### Resistor color code

A resistor is the most important electrical component in almost every electronic circuit, it can limit current to any load such as led, transistor, opamp, etc. We must read resistor color code if we want to know the resistive value, tolerance, temperature coefficient. Resistors have different color bands (3,4,5,6) the more color bands the more resistor's information.Now let's start with 3 bands resistor color code.

The above resistor has only 3 bands First digit, Second digit, and multiply. A 3 bands resistor color code has fixed +/-20% tolerance that means if color code value is 1,000 ohms the real life resistive value may be +/- 200 ohms.
4 band resistor color code

A 4 bands resistor color code has tolerance value color strip, the resistor on an above picture has 5% tolerance. This type of resistor uses in a regular circuit such as television,radio,washing machine.

5 bands resistor color code

A 5 bands resistor color codes have third digit color bands.
1(first digit) 0(second dig…

## Electrical symbol/electronic symbols and functional

### Capacitor symbol

A capacitor is an electronic component that use to block D.C. current, Smoothing DC power supply and it also the important part in R/C circuit, equalizer. A capacitor can store current and bring the current out almost instantly, a big capacitor can melt a metal that short circuit when it charged.
An electrolytic capacitor has polarities, reverse the polarities can make the capacitor explode, damaged and lead to severe injury.

### Diode symbol

A diode is an electronic component that allows current flow only one direction. The current flow from anode to Cathode (+ to -) so the electronic component is used in a rectifier, reverse polarity protection. A silicon diode has a forward voltage of approximately 0.6 volts, a Schottky diode has a lower forward voltage drop and it switching between on and off faster than a silicon diode. A silicon diode has a voltage drop in the component around 0.6 volts so when 12 volts power supply pass through a diode the output drop to 12 - 0.6 = 11.4 volts.

### Hall effect sensor symbol

Hall effect sensor is an electronic component that sends output when detecting the magnetic field. It's widely used for speed meter, brushless motor.A 3144 is a classic hall effect sensor, it sends output low when detecting any magnetic field. See how to use a Hall effect sensor here
http://www.easyandworkproject.xyz/2016/06/hall-effect-sensor-wiring-diagram-and.html

### NPN Transistor symbol

NPN Transistor use in many electronic device, the transistor can amplifly current until it high enough to work for another electronic component in a circuit. The amplifly current gain from NPN transistor call beta(input current x times), the beta value range from 5 to over 500 depending on working current and voltage.  NPN transistor start working when voltage between BASE pin and Emitter pin greater than 0.6 volts.

### Resistor symbol

A resistor is an electronic component that limits current in an electronic circuit. The resistor also can set as voltage divider but output voltage swing when connecting to low resistance load.
A resistor has a color code that shows the resistant value
You can learn how to read the color code here

### Thermistor symbol

A Thermistor is an electronic component that resistance change (decrease or increase depends on model) when temperature increase or decrease. Thermistor has a resistance around 1 - 10 kilo-ohms depends on model, the component is the most important part of temperature sensor circuit, air conditioner, thermal switch.