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# complete guide for tech beginners

by：Top-In     2020-01-14
Every start will be heard, but you will succeed if you are motivated and determined.
Most students, especially those majoring in engineering, want to make a difference.
The practical experience of doing something makes our study perfect and helps us understand the truth.
While this is very important, most students do not get the right guidelines and do not start from where he should be.
I believe this tutorial will help technical beginners and enthusiasts to start any project.
Buy any type of component you may access: very basic stuff for electronics, and I know you are already familiar with these.
Let\'s recall.
Each substance is made up of atoms, and one atom has three types of particles.
Electrons are one of these particles with negative electricity.
Charge is the property of electrons and protons.
The proton is positively charged.
The charge of an electron is called a unit charge.
In conductive materials (
Silver, copper, gold, aluminum, etc)
There are many free electrons in random motion.
Voltage is a force or pressure that forces an electron to flow or move in a specific direction.
When the Wizard applies a voltage, the electron begins to move in a fixed direction, and the flow of the electron in a specific direction is called a current.
When electrons move in conductors, they face some friction.
This friction is called resistance.
Resistance against electronic free movement.
So we can say that the resistance reduces the current.
Voltage: voltage is the pressure that forces electrons to flow in a particular direction in a conductor.
The voltage is expressed in V.
The battery is a good source of voltage. 3V, 3. 3V, 3.
7 v and 5 v are the most common in electronic circuits and devices.
Current: current is the flow of electrons in a specific direction.
More formally, the current is the rate of change of the electron in a particular direction.
The unit of current is amps, expressed in I.
In an electronic circuit, the current is in the range of milliamperes (
1 amp = 1000).
For example, the typical current of the LED is 20 mA.
The voltage is the cause and the current is the result.
Resistance: Resistance is an obstacle to the flow of charge or electrons.
The unit of resistance is the SI unit of resistance is Ohm (Ω).
There is an important relationship between these three quantities of voltage, current and resistance: V = IR or I = V/R or R = V/IThis relationship is called Ohm\'s law.
Voltage, current and resistance are measured with voltmeter, ammeter and ohmmeter respectively.
The battery is a source of voltage or a more formal source of electrical energy.
The battery provides electrical energy through internal chemical reactions.
The battery is two terminal devices.
One is the call Terminal (+V)
The other is the negative terminal (-V)or ground.
There are two kinds of batteries.
Use once, discard once.
The secondary battery can be discharged and charged many times.
The battery has many shapes and sizes, from the micro-battery used to power hearing aids and watches to the room-sized battery pack that provides backup power for telephone exchange and computer data centers.
Depending on battery chemistry, there can be multiple types of batteries.
Several common battery types used in robotics and technical projects are discussed below. 1.
5 V battery different size 1.
5 v battery is provided.
AA and AAA are the most common sizes.
The capacity range is 500 to 3000 mAh.
3 v lithium battery-
The shaped cells are thin compared to the diameter.
The rated voltage of all these lithium batteries is 3 volts (on-load)
The open circuit voltage is about 3. 6 volts.
Capacity can range from 30 to 500 mAh.
It is widely used in wearable devices in its small size.
These batteries don\'t need to be recharged.
Can be used in small robots. Nickel-Metal Hydride (NIMH)
These batteries have high energy density and fast charging speed.
Another important feature is the price.
NIMH batteries are cheap in size and capacity.
This type of battery is often used in robotic applications. 3. 7 V Li-ion and Li-
Polymer lithium ion and lithium polymer batteries are rechargeable.
It has the features of large discharge capacity, high energy density, large capacity and small volume. Li-
Polymer batteries are widely used in robotics and RC projects.
Li-specific energy
The poly battery is 100-265 W h/kg.
9 V batterlin-
The most common voltage battery was used in the early transistor radio.
It has a rectangular prism shape with a circular edge and a polarized snap connector at the top.
They are all rectangular in shape;
Size is 48 in height. 5mm, length 26. 5 mm, width 17. 5 mm (or 1. 9\"x1. 0\"x0. 68\").
Both terminals are at one end and 1/2 in the center (12. 7 mm)apart.
Capacity is about 600 mAh.
Lead-acid batteries are the main force of industrial batteries.
They are very cheap, rechargeable and easy to buy.
Lead-acid batteries are used in mechanical equipment of UPS (
Uninterrupted power supply)
Robots and other systems that require a lot of power and are less important in weight.
Lead-acid batteries have 2 v batteries, which means you can have an even v battery.
The most common voltages are 2 V, 6 V, 12 V and 24 V.
The series-parallel connection of the battery can be connected in series or parallel.
When connected in series, the voltage level increases, and the current capacity increases when connected in parallel.
Two important things about the battery: the battery capacity is a measure (
Usually in the amplifier-hr)
The quality of the charge stored by the battery is determined by the quality of the active substance contained in the battery.
The battery capacity represents the maximum energy that can be extracted from the battery under specific conditions.
However, the actual energy storage capacity of the battery may vary greatly from the \"nominal\" rated capacity, because the battery capacity depends largely on the life of the battery and the history of the past, charging or discharging status and temperature of the battery.
Battery capacity in Watt-hours (Wh), kilowatt-hours (kWh), ampere-hours (Ahr)or milliampere-hour (mAh). A Watt-
The hour is the voltage (V)
What is the current provided by the battery multiplied (Amps)
The battery can provide a certain amount of time (
Usually in hours).
Voltage * amps * hours = Wh.
Due to the internal chemical properties of the battery type, the voltage is almost fixed (
Alkaline, lithium, lead acid, etc)
, Usually only the AMP * hour measurement is printed on the side, expressed in Ah or mAh (1000mAh = 1Ah).
To get Wh, multiply Ah by the nominal voltage.
Let\'s say, for example, that we have a 3 v nominal battery of 1Amp-
Therefore, it has a capacity of 3 watts.
Lower drain current will make the battery capacity better.
To determine the battery life, divide the capacity by the actual load current to get the life hour.
The 10 ma circuit powered by a 9 volt rectangular battery will work for about 50 hours: 500 mAh/10 ma = 50 hours.
In many types of batteries, the entire energy stored in the battery cannot be extracted (
In other words, the battery cannot be fully discharged)
It will not cause serious and often irreparable damage to the battery.
Discharge depth (DOD)
The power of the battery determines the power score that can be taken out of the battery.
For example, if the manufacturer gives the battery a DOD of 25%, the load can only use 25% of the battery capacity.
The charging/discharge rate affects the rated battery capacity.
If the battery is discharged very fast (i. e.
High discharge current)
, The amount of energy that can be extracted from the battery is reduced, and the battery capacity is reduced.
Alternatively, using low current to discharge at a very slow rate, more energy can be extracted from the battery and the battery capacity is higher.
For example, a coin battery with a rated current of 1 Ah can\'t actually provide an hour of current of 1 amp, in fact it can\'t even provide 0 amps.
1 amp, there is no excessive extension in itself.
It\'s like saying that a person has the ability to run 30 miles: of course, running 30 miles is a big difference from walking!
Again, the 1Ah coin battery offers 1 mA in 1000 hours is no problem, but it will last less than 10 hours if you try to extract 100 mA from it.
The temperature of the battery also affects the energy extracted from the battery.
At higher temperatures, the battery capacity is usually higher than the lower temperature.
However, deliberately increasing the temperature of the battery is not an effective way to increase the capacity of the battery, because this will also reduce the battery life. C-
Rate: C-measurement of charge and discharge current of the batteryrate.
In addition to lead acid, most portable batteries are rated at 1C.
1C discharge produces a current equal to the rated capacity.
For example, if you discharge at 1C rate, a battery with a rated power of 1000 can provide 1000 mA of the power for 1 hour.
The same battery discharged at 0.
5C offers 500 mA in two hours
At 2C, the same battery can provide 2000 mA of the power in 30 minutes.
1C is usually called one-hour discharge; a 0.
5C will be two.
Hour, a 0.
1C discharge for 10 hours.
The capacity of the battery is usually measured with a battery analyzer.
If the capacity reading of the analyzer is displayed as a percentage of the nominal rating, 100% is displayed, and if 1000 mA can be extracted from the battery when the rated power is 1000 for one hour.
If the battery lasts only 30 minutes before cutting-
Off, showing 50%.
New batteries sometimes provide more than 100% capacity.
In this case, the rated power of the battery is conservative and can withstand a longer discharge time than specified by the manufacturer.
The charge rate is usually expressed as C or C-
Rate, indicating the charge or discharge rate equal to the battery capacity within one hour.
The battery charger can be specified according to the battery capacity or C rate;
The charger rated C/10 will restore the battery capacity within 10 hours, and the charger rated 4C will charge the battery within 15 minutes.
Charging speed is very fast, 1 hour or less, usually requires the charger to carefully monitor battery parameters such as terminal voltage and temperature to prevent excessive charging and battery damage.
How is the battery measured? This is very direct. How big is the battery?
Lead-acid batteries will not be much smaller than C. Battery.
Coin batteries will not be much bigger than a quarter.
There are also standard sizes such as AA and 9 v, which may be desirable.
Weight and power density this is a performance problem: higher quality (
And more expensive)
The power density of the battery will be higher.
If weight is an important part of your project, you will want to use a lighter, higher weightDensity battery.
This is usually expressed in Watt.
Hourly per kilogram
Price is almost proportional to power-density (
You pay more for higher density)
Proportional to the power capacity (
You pay more for more capacity).
In smaller, lighter packages, the more power you want, the more you have to pay for it.
The voltage of the voltage battery is determined by the chemicals used internally.
For example, all alkaline batteries are 1. 5V, all lead-
The acid is 2 v and the lithium is 3 v.
The battery can be made up of multiple batteries, so for example, you rarely see 2 v leadsacid battery.
Usually they are connected together internally to make a 6 v, 12 v or 24 v battery.
Similarly, most electronic devices use multiple bases to generate the voltage required for operation.
Don\'t forget that the voltage is a \"nominal\" measurement, a \"1 \".
The 5 V \"AA battery actually starts at 1.
6 v then drops quickly to 1.
Then drift slowly to 1.
At this point, the battery is considered \"dead \". Re-
Some batteries are charged and can usually be charged hundreds of times.
Which battery is suitable for your project?
You see, there are a lot of types of batteries and a lot of types of battery chemistry, so it\'s not easy to decide which solution works best for your project.
If your project is very strong
For example, large audio systems and electric projects, you can choose lead-acid batteries.
If you want to build a wearable project and need small power, you can choose a lithium coin battery.
For any portable lightweight item that requires medium power, you can choose lithium-ion battery.
You can also choose a cheaper nickel. Metal Hydride (NIMH)
The weight is heavier than Li. ion.
If you like power-hungry RC quad-
It may be lithium ion polymer (LiPo)
This is the best option for you as these batteries are small in size, light in weight compared to other types of batteries, fast in charge and high in current output.
If your battery needs a user replacement, then you should choose a universal AA, AAA, or 9 v battery.
If you need a 5 v battery then you can use 3 AAA or AA alkaline batteries (4. 5V)
Or 4 NiMH cells (4. 8V).
Make sure your device operates at these slightly lower voltages (
This is probably the case).
Do you need to use your rechargeable battery for a long time? Use a high-
High quality charger with sensor, can keep proper charge and trickle charge.
A cheap charger will keep your phone out of power.
In: it is an electric component that is resistant to electronic flow.
Resistance is a very basic and common circuit element.
We use resistors to control the current in the circuit.
Controlling current is very important. Electronic Engineering is only an art of controlling current.
You can\'t find any appliances or circuits without resistors.
The resistors are passive components, which means that they consume only power (
Not generated).
Resistors are usually added to the circuit where they are supplemented like op-
Amplifiers, micro-controllers and other integrated circuits.
Resistance is usually used to limit current, voltage and pull-up I/O lines.
The resistance of the resistance is measured by Ohm.
The larger or smaller value of ohms can be compared with kilo-, mega-, or giga-
Make the big value easier to read.
It is common to see resistance in kilohm (kΩ)and megaohm (MΩ)range (
It is less common to see Milly Ohm (mΩ)resistors).
For example, a resistance of 4,700 Ω is equivalent to a 4.
7 k Ω resistance, 5,600,000 Ω resistance can be written as 5, 600 k Ω or (
More often than not5. 6MΩ.
There are thousands of different types of resistors, which are produced in various forms, because their special properties and accuracy are suitable for certain application fields, such as high stability, high voltage, high current, etc, or use them as universal resistors where their properties are not too problematic.
Some common properties related to common resistors are;
Temperature coefficient, voltage coefficient, noise, frequency response, power and resistance temperature rating, physical size and reliability.
According to the conductive properties of the resistance, it can be divided into: Linear resistance is the type of resistance, and the resistance remains unchanged as the potential difference or voltage applied to it increases.
Or the resistance or current through the resistor does not change with the applied voltage (P. D )changes. The V-
This resistance is characterized by a straight line.
Non-linear resistance
Linear resistance refers to the type of resistance through which its current is not fully proportional to the potential difference applied to it.
These types of resistors have non-liner V-
I features and does not strictly follow Ohm\'s law.
There are several types of nonlinear resistors, but the most commonly used ones are: NTC resistors (
Negative temperature Co-efficient)-
Their resistance decreases as the temperature rises. PTC resistors (
Positive temperature Co-efficient)-
As the temperature rises, their resistance increases. LDR resistors (
Optical dependent resistance)-
As the light increases, their resistance decreases. VDR resistors (
Voltage Dependent Resistance)-
When the voltage exceeds a certain value, their resistance decreases sharply.
Use non-linear resistors in different projects.
LDR is used as a sensor in various robot enthusiast projects.
Fixed value resistor according to the value of the resistor: fixed value resistor refers to the type of resistor that has been fixed in the manufacturing process and cannot be changed during use.
Variable resistance or potentiometer: variable resistance or potentiometer is the type of resistance that can change its value during use.
These types of resistors usually contain an axis that can be rotated or moved by hand, or a screwdriver to change its value in a fixed range
0 to 100 ohms.
Potentiometer is used for volume and speed control of different items and equipment.
Package resistors: These types of resistors are a resistor that contains a package containing two or more resistors.
It has many terminals, the resistance of the resistor can be selected by using any two terminals in the available terminals, and can also be used as a resistance array for various purposes.
Composition-based: carbon composition: These types of resistors are made up of carbon particles that are combined by the combination of resignation.
The ratio of the carbon particles used and the resignation determines the value of the resistance.
At both ends of the composition, there is a metal cover with a small tin rod connected to weld it or use it in the circuit, and then package the whole package in a plastic box, to prevent moisture and reaction with air.
These types of resistors usually create noise in the circuit, because electrons pass through one carbon particle to another, so these types or resistors are not used in key circuits, although cheap.
Carbon Deposition: The Resistance made by depositing a thin layer of carbon around the ceramic rod is called carbon deposition resistance.
They are made by heating ceramic rods in a methane flask and depositing carbon around them through a glass breaking process.
The value of the resistor is determined by the amount of carbon deposited around the ceramic bar.
Metal film: the resistance of the metal film is made by vacuum deposition of evaporated metal on the ceramic core rod.
These types of resistors are very reliable with high tolerance and high temperature coefficient.
These types of resistors cost more than others, but are used in critical systems.
Wire winding: wire winding resistance is made by winding the metal wire around the ceramic core.
The metal wire is an alloy made of various metals according to the characteristic and resistance of the required resistance.
These types of resistors have high stability and can also withstand high power, but are usually larger in size compared to other types of resistors.
Ceramic metals: These types of resistors are made by firing certain metals mixed with ceramics on a ceramic base plate.
The ratio of the mixture in the mixed ceramic and metal determines the value of the resistance.
These types of resistors are very stable and they are also very accurate.
These types of resistors are mainly used as surface mount resistors used in smd pcb.
According to the function of the resistance: the precision resistance is a resistance with a very low tolerance value, so they are very accurate (
Close to their face value).
All resistors have a tolerance value, expressed as a percentage.
The tolerance value tells us how close the nominal value of the resistance is.
For example, a 10% resistor with a tolerance value of 500, whose resistance may be between 10% or more (550Ω)
Or less than 10% RMB (450Ω).
If the tolerance of the same resistance is 1%, the resistance will only be 1% different.
Therefore, the resistance of 495 kWh and 505 kWh 500 kWh can vary.
Take tolerance as an example.
A precision resistor is a resistor with a tolerance level as low as 0. 005%.
This means that the precision resistance will only change 0.
From its face value of 005%.
The tolerance percentage value of the precision resistor is very low, making it super precise with the nominal value.
They differ very little from the nominal values, so they are used for high-
Accuracy is necessary in terms of resistance values.
Easy melt resistance: easy melt resistance is a wire-
Winding resistance, which is designed to burn easily when the rated power of the resistor exceeds.
In this way, the melt resistance has a dual function.
It acts as a resistance limiting current when it does not exceed the power.
When the rated power is exceeded, it acts as a fuse, burns up and becomes open in the circuit to protect the elements in the circuit from excess current.
Cement resistance: the cement resistance is the power resistance of heat resistance and flame retardant.
The cement resistance is used to handle a large amount of electricity flowing through it and it will not be damaged by heat or flames.
If you are designing a circuit in which a large amount of current passes through the resistance and needs to resist high temperature and flame, the cement resistance is a good design option.
Typical rated power ranges from 1 w to 20 w or more.
The tolerance from the specified resistance value is about 5%.
Thermal resistor: the thermal resistor is a thermal resistor whose resistance value varies with the operating temperature.
Because of the self
The heating effect of the current in the thermal resistor, the device changes the resistance as the current changes.
The thermal resistor has a positive temperature coefficient (PTC)
Or negative temperature coefficient (NTC).
If the thermal resistor has a positive temperature coefficient, its resistance increases as the operating temperature increases.
Conversely, if the thermal resistor has a negative temperature coefficient, its resistance decreases as the operating temperature increases.
The degree to which the resistance varies with the operating temperature depends on the size and structure of the thermal resistor.
It is best to check the data sheet of the thermal resistor being used to understand all the specifications of the thermal resistor.
Thermal resistors are often used in electronic circuits dealing with temperature measurement, temperature control, and temperature compensation.
Optical resistance device: the optical resistance device is a resistance that changes the resistance value according to the light on the impact resistance surface.
In a dark environment, the resistance of the optical resistor is very high, and there may be several m MOSFETs, depending on the resistance level of the specific optical resistor in use.
When the strong light shines on the surface, the resistance of the optical resistance decreases sharply, possibly to 400 kWh.
Therefore, the optical resistor is a variable resistor whose resistance value varies with the amount of light hitting its surface. Leaded and non-
Lead resistance type lead resistance: this type of resistance has been used since the first electronic element was put into use.
Normally, the assembly is connected to a terminal in one form or another, and leads from the resistor element are required.
Over time, printed circuit boards are used and leads are inserted through holes on the board, usually welded on the reverse side of finding the track.
Surface mounting resistance: these resistance types have been used more and more since the introduction of surface mounting technology.
Typically, this type of resistance is made using thin film technology.
A complete range of values can be obtained.
Electronic Industry Association (EIA)
And other authorities, specifying standard values for resistors, sometimes called \"preferred values\" systems.
The preferred value system originated early in the last century, when most resistors were carbon-
Make graphite with relatively poor tolerance.
The reason is simple-
Select the value of the part based on the tolerance that can make the part.
Take 10% tolerance devices as an example, assuming that the first preferred value is 100 ohms.
It makes no sense to produce a resistance of 105 ohms, as 105 ohms falls within the 10% tolerance range of the 100 ohm resistance.
The next reasonable value is 120 ohms, because the value of a 100 ohm resistor with a tolerance of 10% is expected to be between 900 and 110 ohms.
The value of the 120 ohm resistance is between 110 and 130 ohms.
According to this logic, the preferred value is 10% tolerance 100 to 1,000 ohm resistor 100,120,150,180,220,270,330, etc (
Appropriate rounding);
This is the E12 series shown in the table below.
The EIA \"E\" series specifies the preferred value for various tolerances.
The numbers behind \"E\" specify the number of log steps per decade.
The table below is a standardized table for ten years between 100 and 1,000.
The value in any decade can be obtained by dividing the table entry by or multiplying by the power of 10.
The series is as follows: E6 20% tolerance, E12 10% tolerance, E24 5% tolerance (
And usually 2% tolerance)
, E48 2% tolerance, E96 1% tolerance, E192. 5, . 25, .
1% and higher tolerances.
Ten-year resistance value of standard EIA: E6 series :(20% tolerance)
Series 10, 15, 22, 33, 47, 68 E12 :(10% tolerance)
Series 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 E24 :(5% tolerance)
10, 11, 12, 13, 15, 16, 18, 20, 22, 24, 27, 30, 33, 36, 39, 43, 47, 51, 56, 62 68 series 75, 82 and 91 E48 :(2% tolerance)
100,105,110,115,121,127,133,140,147,154,162,169,178,187,196,205,215,226,237,249,261, 274, 287, 301, 316, 332, 348, 365, 383, 402, 422 cm, 442 cm, 464 cm, 487 cm, 511 cm, 536 cm, 562 cm, 590 cm, 619 cm, series 649 cm, 681 cm, 715 cm, 750 cm, 787 cm, 825 cm, 866 cm, 909 cm, 953 cm E96 :(1% tolerance)
100,102,105,107,110,113,115,118,121,124,127,130,133,137,140,143,147,150,154,158,162, 165, 169, 174, 178, 182, 187, 191, 196, 200, 205,210,215,221,226,232,237,243,249,255,261,267,274,280,287,294,301,309,316,324,332, 340, 348, 357, 365, 374, 383, 392, 402, 412 series 422,432,442,453,464,475,487,491,511,523,536,549,562,576,590,604,619,634,649,665,681, 698, 715, 732, 750, 768, 787, 806, 825, 845, 866, 887, 909, 931, 959, 976 and E192 :(0. 5, 0. 25, 0. 1 and 0. 05% tolerance)
100,101,102,104,105,106,107,109,110,111,113,114,115,117,118,120,121,123,124,126,127, 129, 130, 132, 133, 135, 137, 138, 140, 142, 143,145,147,149,150,152,154,156,158,160,162,164,165,167,169,172,174,176,178,180,182, 184, 187, 189, 191, 193, 196, 198, 200, 203, 205,208,210,213,215,218,221,223,226,229,232,234,237,240,243,246,249,252,255,258,261, 264, 267, 271, 274, 277, 280, 284, 287, 291, 294,298,301,305,309,312,316,320,324,328,332,336,340,344,348,352,357,361,365,370,374, 379, 383, 388, 392, 397, 402, 407, 412 417, 422,427,432,437,442,448,453,459,464,470,475,481,487,493,499,505,511,517,523,530,536, 542, 549, 556, 562, 569, 576, 583, 590, 597, 604,612,619,626,634,642,649,657,665,673,681,690,698,706,715,723,732,741,750,759,768, 777, 787, 796, 806, 816, 825, 835 845, 856, 866, 876, 887, 898, 909, 920, 931, 942, 953, 965, 976, 988, when designing the equipment, keep the lowest E-
First, the series part. e.
Using E6 is better than using e12.
In this way, the number of different parts in any device can be minimized.
If ten years are worth it, I. e.
100R, 1 k, 10, etc. can be used better.
These are very common resistor values and are widely used.
It also reduces the variety of components and makes inventory easier to manage.
For many digital designs where the resistor is used as a pull-up or drop-down, the value of the resistor has little effect, which is easy.
This is a bit complicated for analog design and requires E12 or E24 values.
High precision and close tolerance requirements require values of the E48, E96 and even the E192 series.
Because the higher order series are used less, the cost is usually also higher.
Using common resistor values can reduce costs or inventory.
Details: learn many different types of resistors that can be used in electrical and electronic circuits to control current flow or to generate voltage in a variety of different ways.
But in order to do this, the actual resistance needs to have some form of \"resistance\" or \"resistance\" value.
Resistance can obtain a series of different resistance values from the fraction of ohms (Ω )
Millions of ohms.
When the resistor body is large enough to read printing, resistance values, tolerances, and wattage ratings are usually printed on the resistor body in the form of numbers or letters, such as high-power resistors.
But when the resistance is small, such as the carbon or film type of 1/4 W, these specifications must be shown in other ways because the printing is too small to read.
Therefore, in order to overcome this problem, the small resistor uses color painting to bring the resistance value and tolerance indicating it, and the physical size of the resistor indicates its wattage rating.
These color paint strips produce an identification system commonly referred to as a resistance color code.
Many years ago, an international universal resistance color code scheme was developed as a simple and quick way to identify Ohm values regardless of the size or condition of the resistor.
It consists of a single color ring or band representing the spectral order of each digit of the resistance value.
The resistance color code Mark always starts from left to right, reading a band at a time, and the larger width tolerance band faces the right side, indicating its tolerance.
By matching the color of the first band with its associated number in the numeric column of the color chart below the first digit, this represents the first digit of the resistance value.
Similarly, by matching the color of the second band with its associated number in the numeric column of the color chart, we get the second number of the resistance value, and so on.
Then read the resistance color code from left to right, as shown in the figure.
Tips for reading resistance codes the direction of reading may not always be clear.
Sometimes the added space between Band 3 and band 4 gives the direction of reading.
Also, the first band is usually the closest to the lead.
Gold or silver bands (the tolerance)
Always the last band.
It is a good practice to check the manufacturer\'s documentation to determine the coding system used.
The better way is to use multiplemeter.
In some cases this may even be the only way to find out the resistance;
For example, when the ribbon is burned.
The surface mounting resistor or SMD resistor is a very small rectangular metal oxide film resistor designed to be welded directly to the surface of the circuit board, hence its name.
The surface mounting resistance usually has a ceramic substrate body on which a thick layer of metal oxide resistance is deposited.
The resistance value of the resistance is controlled by increasing the required thickness, the length or type of deposited film used, and a highly accurate low tolerance resistance, down to 0.
Can be produced 1%.
They also have metal terminals or covers at both ends of the body, which allows them to be welded directly to the printed circuit board.
3 or 4-printing for surface mounting resistors
Digital digital code, similar to the digital code used on the more common axial resistance to represent the resistance value.
Standard SMD resistors are marked with three-
Digital code, the first two of which represent the first two digits of the resistance value, the third is the multiplier, x1, x10, x100, etc.
For example: \"103\" = 10 × 1,000 Ohm = \"392\" of 10 kilogrammes = 39 × 100 Ohm = 3.
The \"563\" of 9 K Ω = 56x1,000 Ohm = \"105\" of 56 K Ω = 10x100,000 Ohm = 1 M Ω surface mounting resistance with a value of less than 100 Ω is usually written: \"390\", \"470\", \"560\", and the last zero represents the 10 ^ 0 multiplier, which is equivalent to 1.
For example: \"390\" = 39 × 1 Ω = 39 Ω or 39r Ω \"470\" = 47 × 1 Ω = 47 Ω or 47 R Ω the value of the resistance value of less than ten has a letter \"R decimal point, so 4R7 = 4. 7Ω.
The surface mounting resistance with \"000\" or \"0000\" marks is zero-Ohm (0Ω)
Because the resistance of these components is zero, the resistance, or in other words, short circuit.
In electronics, the resistance is always paired together, usually in series or parallel circuits.
When resistors are connected in series or in parallel, they produce a total resistance, and one of the two equations can be used to calculate the total resistance.
If you need to create a specific resistor value, it will be convenient to know the way the resistor value is combined.
Series resistance when series resistance value, simply add up.
So, for example, if you only need a 12.
33 k Ω resistance, find some common resistance values of 12 k Ω and 30 Ω, and connect them in series.
The resistance of parallel resistance is not so easy to find the resistance of parallel resistance.
The total resistance of the N resistors in parallel is the reciprocal of the sum of all the inverse resistors.
This equation may make more sense than the last sentence.
Some examples of resistance limits apply resistance as the main use of current limiting devices.
Resistance is the key to ensuring that the led does not explode when powered on.
By connecting the resistor in series with the LED, the current flowing through both components can be limited to the safety value.
Note the circuit given below.
Resistor R is in series with LED.
In order to calculate the value of the led current limiting resistor, two important factors should be considered, namely, the typical forward voltage (Vf)
Maximum forward current (If).
The typical forward voltage is the voltage required to make the LED light up, and it will change (
Usually between 1. 7V and 3. 4V)
Depending on the color of the LED.
The maximum forward current of the basic LEDs is usually around 20 mA;
The continuous current through the LED should always be equal to or less than that rated current.
Once you get the value of Vf, if you can use the formula to calculate the size of the current limiting resistor: R = (Vs -Vf)
/Ifwhere, Vs is the supply voltage.
For our case, let\'s assume that we supply power from the 5 v power supply, the led forward voltage is 1. 8 V.
Resistance value of led current of 10 mA: R = (5 -1. 8)/ 10 = 320 ohm.
The voltage divider is a resistor circuit that converts a larger voltage into a smaller voltage.
Using only two series resistors, the output voltage can be generated, which is only a small part of the input voltage, depending on the ratio of the two resistors.
In the circuit on the right, the two resistors R1 and R2 are connected in series and have a voltage source (Vin)
Connect through them.
The voltage from Vout to GND can be calculated as: Vout = Vin x R2 /(R1 + R2)
For example, if R1 is 1.
7 k Omega, R2 is 3.
3 k Ω, 5 v input voltage can be turned into 3.
3 v at the Vout terminal.
The voltage divider is very convenient for reading resistance sensors like photocells, flexible sensors, and force sensors
Sensitive resistance.
Half of the voltage divider is the sensor, which is a static resistor.
The output voltage between the two components is connected to the simulation-to-
Digital converter on the micro controller (MCU)
Read the value of the sensor. Pull-
Pull up the resistance-
When you need to bias the input pin of the micro-controller to a known state, use the up resistor.
One end of the resistor is connected to the pin of the MCU and the other end is connected to the high voltage (Usually 5 V or 3. 3V). Without a pull-
Up resistance, the input on the MCU can remain floating.
There is no guarantee that the floating pin is either very high (5V)or low (0V). Pull-
When connected to a button or switch input, the up resistor is usually used. The pull-
Up resistance can bias input-
The pin when the switch is on.
When the switch is off, it protects the circuit from short circuit.
In the circuit above, when the switch is on, the input pin of the MCU is connected to 5 v by resistor.
When the switch is off, the input pin is connected directly to the GND.
Value of pull-
The Up resistor usually does not need to be specified.
But it should be high enough that if a voltage of about 5 v is applied on it, not much power will be lost.
Usually the value around 10 k Ω works well.
The capacitor is a bit like a battery, but it has different work to do.
The battery uses chemicals to store electrical energy and is slowly released through the circuit; sometimes (
In the case of a quartz watch)
It may take several years.
Capacitors usually release energy faster.
Usually in a few seconds or less.
For example, if you are taking a flash photo, you need your camera to generate a huge burst of light in a second.
The capacitor connected to the flash uses the energy of the camera battery to charge for a few seconds. (
It takes time to charge the capacitor, which is why you usually have to wait a bit. )
Once the capacitor is fully charged, it can release all the energy in an instant through a xenon flash. Zap!
From very small capacitor beads for resonant circuits to large power factor correction capacitors, there are many different types of capacitors to choose from, but they all do the same thing and they store the charge
The basic form of the capacitor is conductive by two or more parallel (metal)
Plates that are not connected or in contact with each other, but are electrically separated by air or some form of good insulating material (such as wax paper, cloud chips, ceramics, plastic for electrolytic capacitors or some form of liquid gel.
The insulation layer between the electrical container plates is usually called the dielectric layer.
Typical capacitance due to this insulation, the DC current cannot flow through the capacitor because it blocks the capacitor, thus allowing the voltage to exist between the plates in the form of a charge.
The electrical energy that a capacitor and a capacitor can store is called a capacitor.
The capacitance of the capacitor is a bit like the size of the bucket: The larger the bucket, the more water can be stored;
The larger the capacitor, the more power the capacitor can store.
There are three ways to increase the capacitor capacitance.
One is to increase the size of the plate.
The other is to move the plate closer.
The third method is to make the dielectric material a good insulator as much as possible.
Capacitors use media made of various materials.
In a transistor radio, tuning is performed by a large variable capacitor, nothing but the air between the plates.
In most electronic circuits, the capacitor is a sealed element made of ceramic, such as a cloud chip and glass, paper or plastic soaked in oil (such as mylar ).
The size of the capacitor is called farads (F)
Michael Fard, British electrical pioneer (1791–1867).
A farad is a lot of capacitors, so in practice, most of the capacitors we encounter are just part of the farad.
Typical micro-Law (
A few parts per million of a farad, written by μ f), nanofarads (thousand-
Farad wrote a few parts per million of nF)
, And picofarads (
Millions of farad (pF).
The extra charge for the storage of the super capacitor is sometimes rated as thousands of farads.
There are many different types of capacitors in the types of capacitors, and their properties are different and each has its own advantages and disadvantages.
Some types of capacitors can be charged to a higher voltage and, therefore, can be used for high voltage applications.
Some capacitors can be charged to very high charges, such as aluminum electrolytic capacitors.
The leakage rate of some capacitors is very low, while the leakage rate of some other capacitors is very high.
All these factors determine how each capacitor is used and how it is applied in the circuit.
According to the design, the capacitors are divided into the following different types: Electrolytic type: for most applications, we use electrolytic type capacitors.
They are very important for e-students because they are easy to get and use and are also cheap.
When a very large capacitor value is required, an electrolytic capacitor is usually used, usually more than 1 μF.
Here, instead of using a very thin layer of metal film for one of the electrodes
Use a liquid electrolyte solution in the form of jelly or paste as the second electrode (
Usually cathode).
The dielectric is a very thin oxide layer that is electrically grown
In production, the thickness of the film is less than ten microns.
This insulation layer is very thin, so it is possible to make capacitors with a larger capacitance value in the case of a smaller physical size, because the distance d between the plates is very small.
Most electrolytic types of capacitors are polarized, that is, the DC voltage applied to the capacitor terminals must be the correct polarity, I . E. e.
Positive terminals are positive terminals and negative terminals are negative terminals, because incorrect polarization can destroy the insulating oxide layer and may cause permanent damage.
The polarity of all polarized electrolytic capacitors is clearly marked with a negative number to indicate the negative terminal, and this polarity must be followed.
Electrolytic capacitors are commonly used in DC power supply circuits because of their large electrical capacity and small size to help reduce ripple voltage, or for coupling and decoupling applications.
One of the main disadvantages of electrolytic capacitors is that the voltage ratings are relatively low, and because of the polarization of electrolytic capacitors, they cannot be used on AC power supplies.
There are generally two basic forms of electrolysis;
Aluminum electrolytic capacitors and ta electrolytic capacitors.
Electrolytic capacitors are usually marked with these things: 1.
Capacitance value. 2.
Maximum voltage. 3.
Maximum temperature. 4. Polarity.
For electrolytic capacitors, the capacitance is measured by micromethod.
Select the appropriate capacitor as needed.
With the increase of the capacitor, the size of the capacitor also increases.
The voltage rating of the capacitor or all capacitors has a maximum voltage rating, and when selecting the capacitor, the amount of voltage to be applied on the capacitor must be considered.
The data sheet usually gives the maximum amount of voltage that can be applied to the capacitor without damaging its dielectric material, such as: WV ,(Operating voltage)or as WV DC, (
DC operating voltage).
If the voltage applied to the capacitor becomes too large, the dielectric breakdown (
Called electrical fault)
There will be an arc between the electrical container plates, resulting in a short circuitcircuit.
The working voltage of the capacitor depends on the type of dielectric material used and its thickness.
The DC operating voltage of the capacitor is like this, and the maximum DC voltage of the capacitor with a DC voltage rating of 100 V instead of the maximum AC voltage cannot safely withstand the AC voltage of 100 V.
Because the AC voltage has r. m. s.
The value is 100 V but the peak is over 141 V! .
The capacitor required to work under 100 v ac should then have a working voltage of at least 200 V.
In practice, the capacitor should be selected so that its operating voltage DC or AC is at least 50% higher than the maximum effective voltage applied to the capacitor.
Polyester type: a polyester capacitor is a capacitor consisting of a metal plate with a polyester film between the metal plates, or a metal film deposited on an insulator.
The polyester capacitor is available in the range of 1nF to 15 f and the operating voltage is from 50 v to 1500 V.
Their tolerance ranges are 5%, 10% and 20%.
They have a high temperature coefficient.
They have high isolation resistance, so they are a good choice capacitor for coupling and/or storage applications.
Compared to most other types, the unit volume capacitance of the polyester capacitor is very high.
This means that more capacitors can be installed in smaller capacitors physically.
This feature, coupled with its relatively low price, makes the polyester capacitor a capacitor that is widely used, popular and cheap.
Ta type: ta capacitor is a capacitor made of pentoxide sodium.
Like aluminum, ta capacitors are electrolytic capacitors, which means they are polarized.
Their main advantages (
Aluminum Capacitors in particular)
They are smaller, lighter and more stable.
They have a lower leakage rate and a smaller inductance between leads.
However, their disadvantages are the low storage of the maximum capacitor and the low maximum operating voltage.
They are also more vulnerable to high current spikes.
For the last reason, ta capacitors are mainly used for analog signal systems that lack high currentspike noise.
Ceramic Capacitors: Commonly known as ceramic capacitors or disc capacitors, are two sides of a small porcelain plate or ceramic plate coated in silver and then stacked together to make capacitors.
For very low capacitance values, one is about 3-6mm is used.
Ceramic capacitors have high dielectric constant (High-K)
And a relatively high capacitance can be obtained at a smaller physical size.
Ceramic capacitors have large non-
The capacitance changes linearly with temperature and is therefore used as a de-coupling or by-
Through capacitors because they are also non-
Polarization device.
The numerical range of ceramic capacitors ranges from a few to one or two micromethods ,(μF )
But their rated voltage is usually very low.
Capacitors of ceramic type usually have 3-
Digital code printed on the body to pico-farads.
Typically, the first two represent the capacitor value, and the third represents the number of zeros to be added.
For example, ceramic disc capacitors marked 103 will indicate 10 and 3 zeros in pico-
Farads equal to 10,000 pF or 10nF.
Similarly, the number 104 represents 10 and 4 zeros in pico-
Equivalent to farads such as 100,000 pF or 100nF.
So in the ceramic capacitor image above digital 154, pico-
Farads equal to 150,000 pF or nf or 0. 15uF.
Sometimes letter codes are used to represent their tolerance values, such as: J = 5%, K = 10%, or M = 20%, etc.
The general use of capacitor inductance is a passive electronic component that stores energy in the form of a magnetic field.
As we know, the resistance can resist the flow of the current, and the inductance can resist the change of the flow current through it.
Therefore, for DC current inductor, it is like a conductor.
In other words, the inductor can resist or oppose the change of current, but it is easy to pass through the steady-state DC current.
The current flowing through the inductor produces a magnetic flux proportional to it.
But unlike a capacitor, which opposes the change in voltage at both ends of the plate, an inductor opposes the rate of change in current flowing through it due to self accumulation
Induction energy in a magnetic field.
In the most basic form, the inductor is nothing more than a coil wound around the center core.
For most coils, the current flowing through the coil produces a magnetic flux proportional to the current flow.
Also known as the inductor of the choke.
The inductor is formed with a line tightly wound on the solid center core, which can be either a straight cylindrical rod or a continuous loop or ring to concentrate the magnetic flux.
The schematic diagram of the inductor is the schematic diagram of the coil, so the coil can also be called the inductor.
The inductor is usually classified according to the type of internal core, such as the hollow core (free air)
, By adding continuous or dotted parallel lines next to the online coil to distinguish the solid core or soft iron core with different core types, as shown below.
The standard unit of inductance is Henry, abbreviated as H.
This is a big unit.
The more common unit is microhenry, abbreviated as h (1 µH =10^-6H)
And millihenry, abbreviated as mH (1 mH =10^-3 H).
Occasionally, Henry Nano (nH)is used (1 nH = 10^-9 H).
The application of induttorsfiltersindutors is widely used in capacitors and resistors to create filters for analog circuits and signal processing.
With this alone, the inductor has a low function
Pass the filter because the impedance of the inductor increases as the signal frequency increases.
When combined with the capacitor, the impedance of the capacitor decreases with the increase of the signal frequency, and a notch filter that allows only a certain frequency range to pass can be made.
By combining capacitors, inductors, and resistors in a number of ways, you can create an advanced filter topology for any number of applications.
Most electronics use filters, although since capacitors are smaller and cheaper, capacitors are often used instead of inductor when possible.
The sensor contactless sensor is highly praised for its reliability and ease of operation, and the inductor can be used to sense the presence of magnetic fields or penetrating materials from a distance.
At almost every intersection with traffic lights, induction sensors are used to detect vehicle traffic and adjust the signal accordingly.
These sensors work very well on cars and trucks, but some motorcycles and other vehicles do not have enough features and the sensors cannot be detected by adding h3 magnets to the bottom of the vehicle, there will be no extra boost.
There are two main limitations of the induction sensor, the object to be detected must be magnetic, and the current is induced in the sensor, or the sensor must be energized to detect the presence of the material interacting with the magnetic field.
This limits the application of induction sensors and has a significant impact on the design of using them.
A transformer that combines an inductor with a shared magnetic circuit will form a transformer.
The transformer is a basic component of the State Grid and can be found in many power supplies, or the voltage can be raised or lowered to the desired level.
Since the magnetic field is generated by a change in current, the faster the current changes (
Frequency increase)
The more effective the transformer is.
Of course, as the input frequency increases, the impedance of the inductor begins to limit the effectiveness of the transformer.
The indutors snormally inductor is in a fixed position and is not allowed to move to align with any magnetic field nearby.
The induction motor converts electrical energy into mechanical energy using the magnetic force applied to the inductor.
The induction motor is designed to generate a rotating magnetic field in a timely manner in the case of AC input.
Since the rotational speed is controlled by the input frequency, the induction motor is usually used for applications with fixed speed and can be powered directly from a power supply at 50/60 hz.
Compared to other designs, the biggest advantage of the induction motor is that there is no need for electrical contact between the rotor and the motor, which makes the induction motor very sturdy and reliable.
Energy storage capacitors and inductors can be used for energy storage.
Unlike capacitors, the inductor has a great limit on the time it takes to store energy, because the energy is stored in the magnetic field, and once it is powered off, the magnetic field crashes quickly.
The main use of the inductor as an energy storage is in the switch-
Mode power supply, such as power supply in PC.
In the simpler, non-Isolation Switch-
Mode power supply, replacing transformer and energy storage elements with a single inductor.
In these circuits, the ratio of the inductor power-on time to the power-on time determines the input-output voltage ratio.
The inductor is also used for wireless power transmission and electricity
Mechanical relay.
A diode is a special electronic element with two electrodes, called an anode and a cathode.
Most diodes are made from semiconductor materials such as silicon, ge or selenium.
Diodes can be used as rectifier, signal limiter, voltage regulator, switch, Signal Modulator, signal mixer, signal modem and oscillator.
The fundamental feature of the diode is that it tends to upload only a conductive stream in one direction.
When the cathode is negatively charged with respect to the anode at a voltage greater than a certain minimum, called forward conduction, the current flows through the diode.
If the cathode is positive relative to the anode, it is at the same voltage as the anode, or it is negative compared to the forward conduction voltage, and then the diode does not conduct the current.
This is a simple point of view, but this is correct for diodes that are used as rectifier, switch and qualifier.
The forward conduction voltage is about 6 out of 10 of the voltage (0. 6 V)
For silicon devices, 0.
The Ge device is 3 v and the selenium device is 1 v.
The breakdown voltage if a negative voltage large enough is applied to the diode, it will yield and allow the current to flow in reverse.
This large negative voltage is called the breakdown voltage.
Some diodes are actually designed to work in the breakdown area, but they are not healthy to withstand large negative voltages for most common diodes.
For ordinary diodes, the breakdown voltage is-50V to -
100 V, even more negative.
Many different types of diodes are used in today\'s electronics.
Different types have their own special uses.
I will only discuss more common types.
Rectifier diodes: These diodes are used to correct the AC power input in the power supply.
A rectifier or power diode is a standard diode with a higher maximum rated current.
This higher rated current is usually at the expense of a larger forward voltage.
For example, the rated current of 1N4001 is 1A and the forward voltage is 1. 1V.
Signal diode: small signal diode is small non-
Linear semiconductor, usually used in electronic circuits involving high frequency or small current in television, radio and digital logic circuits.
Small signal diodes are smaller in size compared to conventional power diodes.
They usually have a medium.
The forward voltage drop is high and the maximum current rating is low.
A common example of a signal diode is 1n4148.
Very common, the typical forward voltage is reduced to 0.
72 V with a maximum forward current rating of 300 mA.
Schottky diodes: These diodes have lower forward voltage drop compared to ordinary silicon pn junction diodes.
The voltage drop may be between 0. 15 and 0.
Compared with 0, 4 volts at low current.
6 V voltage of silicon diode.
To achieve this performance, the structures of these diodes are different from those of ordinary diodes, where metals are in contact with semiconductors.
Schottky diodes are used for RF applications, rectifier applications, and clamping diodes.
Zina diode: Zina diode is a strange abandon in the diode family.
They are usually used to carry out the reverse current intentionally.
The Zina is designed to have a very precise breakdown voltage called a Zina breakdown or a Zina voltage.
When sufficient current is reversed through Zener, the voltage drop at both ends of it will remain stable at the breakdown voltage.
The Zener diode utilizes its breakdown properties and is commonly used to produce known reference voltages at the Zener voltage.
They can be used as voltage regulators for small loads, but they are not really used to regulate the voltage of the circuit that will produce a lot of current. Light-
LEDs: like normal diodes, LEDs only allow current to pass through one direction.
They also have a forward voltage rating, which is the voltage they need to light up.
The VF rating of the LED is usually greater than the VF rating of the normal diode (1. 2~3V)
, It depends on the color of the LED.
For example, the rated forward voltage of the ultra-bright blue LED is about 3.
3 v, and only 2 super bright red LED of the same size. 2V.
I will discuss LEDs in more detail later.
Diodes: diodes are used to detect light and have a wide and transparent junction.
Typically, these diodes work in reverse bias where a small amount of current from light can even be easily detected.
Diodes can also be used for power generation, as solar cells, and even for light metering.
Laser diode: This diode is different from the LED because it produces coherent light.
These diodes are widely used in DVD and CD drivers, laser indicators and other fields.
Laser diodes are more expensive than LEDs.
However, they are cheaper than other forms of laser generators.
In addition, the lifetime of these laser diodes is limited.
LEDs are often called LEDs and are truly unsung heroes in the electronic world.
They do dozens of different jobs that can be found in a variety of devices.
Among other things, they form numbers on the digital clock, transfer information from the remote control, light up the watch and tell you when to turn on the appliance.
They are collected together to form an image on a giant TV screen or to light up the traffic lights.
Basically, LEDs are just small bulbs simply installed in the circuit.
But unlike ordinary incandescent lamps, they don\'t burn out fine wires and don\'t get particularly hot.
They are only illuminated by the movement of electrons in semiconductor materials, and they are as long as standard transistors.
The life of the LED exceeds the short life of the incandescent lamp by thousands of hours.
To make thinner TVs, tiny LEDs have replaced the tubes that light up LCD HD TVs.
Led is mainly used in both lighting and indication.
Lighting refers to \"shining light on something \"--
Like a flashlight or headlights.
You want your headlights to turn on like ghosts.
Instructions refer to \"pointing out something \"-
Just like a turn light or brake light on a car.
You don\'t want your car to turn the lights on the blind!
The diffuse LEDs are very good at indication and look soft and uniform and can see them well from any angle.
Clear led very good at lighting, direct and powerful light
But you can\'t see them well from an angle because the light will only move on.
LED circuit design LED is a diode, it is biased with current instead of voltage.
To put it simply, when the LED is \"injected\" by some positive current (
Positive and negative, or anode to cathode, it will start to shine at the minimum current.
A typical red LED takes about 10 mA to 20 mA of the current to get a good brightness.
No more help. -
When the limit is exceeded, the LED is under pressure and may be destroyed.
Since the LED is a current device, the voltage cannot be applied directly on it, so the LED cannot be directly connected to the battery or power supply.
The LED will be destroyed immediately because the current is too large.
Current must be reduced.
The easiest way is to use a resistor.
The resistor will reduce the current and reduce the voltage to a manageable level.
So, how do we calculate what value resistors are used?
We will use Ohm\'s law for this.
Ohm\'s law states that the voltage is the product of the current and the resistance, or V = IR where \"I\" is the current.
Calculate the LED resistor value with the following formula: LED resistor value, R = (Supply Voltage-LED voltage)
For example, let\'s say we use a 9 v battery and then the supply voltage is = 9 v.
Starting from step 2, the LED voltage of the red LED is 2.
0 v LED current is 20 mA (
This is a typical value if the manufacturer does not provide it)
If the resistor value is not available, select the nearest standard resistor value, which is larger.
If you want to increase battery life, you can choose a higher resistor to lower the current.
Lower current causes the LED to darken.
For 15 mA led current, R = (9 -2. 0)
/15 mA = 466 ohms, using the next higher standard value = 470 ohms.
Transistors, like many electronic components, can be regarded as a type of electronic switch.
Transistors are much faster than mechanical switches.
There are two types of basic transistors: bi-Polar knot (BJT)and metal-oxide field-effect (MOSFET)
There are actually two versions of BJT: PNP and PNP.
Most circuits tend to use pnknots.
There are hundreds of transistors that work at different voltages, but they all fall into these two categories.
The transistor has different shapes, but has three leads (legs). The BASE -
Is the lead that is responsible for activating the transistor. The COLLECTOR -
This is a positive lead. The EMITTER -
This is negative.
The transistor is really simple.
Very complicated.
A transistor is a miniature electronic component that can do two different jobs.
It can work as an amplifier or switch: When it works as an amplifier, it accepts tiny currents at one end (
An input current)
Generate a larger current (
Output current)at the other.
In other words, it is a current booster.
This is very useful in hearing aids and so on, and this is the first thing that people use transistors.
There is a micro microphone in the hearing aid that can receive the sounds of the world around them and turn them into fluctuating currents.
These are input into a transistor that can lift them up and power the micro speakers, so you\'ll hear a larger version of the sound around you.
Transistors can also be used as switches.
The tiny current flowing through one part of the transistor allows a larger current to flow through the other part of the transistor.
In other words, a small current switch on a larger current.
This is how all computer chips work.
For example, the storage chip contains hundreds of millions or even billions of transistors, each of which can be turned on or off separately.
Since each transistor can be in two different states, it can store two different numbers, zero and one.
With billions of transistors, a chip can store billions of 0 and 1, with almost as many ordinary numbers as letters (
Or what we call characters).