Diode is a semiconductor electronic component that has ½ conductor, the materials often used are germanium (0.3) and silicon (0.7). Semiconductor diodes consist of two parts, namely N and P, in the N part a number of free electrons arise because they contain particles (-), while in the P part a state of electrons breaking away occurs which is often called a "Hole" in this hole is charged (+), in the N part = Cathode leg and P = Anode leg.
Dioda Family
Diode Symbol
Semi Conductor
Components that usually have this code are diodes, transistors and triacs.
Silicon (Si):
- Yes N (Silicon Negative)
- Yes P (Silicon Positive)
Germanium (Ge)
- Ge N (Germanium Negative)
- Ge P (Germanium Positive)
(N) Valence 5: Phospor, arsenic, antimony
(P) Valence 3: aluminum, gallium, boron, indium
A diode is a component made of semiconductor material, which is divided into two types, namely:
- silicon (0.6 - 0.7 volts)
- germanium (0.2 - 0.3 volt)
Diodes are divided into several types with their characteristics, namely:
a. Germanium
- the physical form is small
- Used for electronic circuits with large power output.
- withstand high voltage up to a maximum of 500 volts.
- withstands maximum high current of 10 amperes
- voltage loss is only about 0.7 volts
b. Silicone
- the physical form is small
- often used in adapters as current rectifiers or as electronic switches
- withstand high currents of around 150 amperes maximum
- withstands maximum high voltage of 1000 volts
c. Selenium
- his physical form is large
- used as a current rectifier on motorbikes that use batteries
- voltage loss 1 volt
- only withstands a maximum medium voltage of 30 V, and a maximum current
- 0,5 ampere
The way to make it is by mixing / polluting between valence 5 and 3:
- valence 5 forms a negative polarity (-)
- valence 3 forms positive polarity (+)
1. Zener diode
Transistors and zener diodes are components that are related because they are both made from semiconductor materials, but what differentiates the two is how they work.
The implementation of zener diodes is most often found in voltage stabilizer circuits, see how it works HERE .
This diode has normal characteristics, namely it is passed by current like a normal diode when forward biased. When reverse biased / reversed it will work in the same way, but drops drastically (falls suddenly) when the zener voltage is reached.
Other characteristics are:
- The physical form is small
- Often used in power supply circuits, voltage stabilizers and so on.
- Withstands maximum voltage of 0.7 to 11 volts
- Only withstands small currents, maximum 1 mA to 50 mA.
- The voltage loss in a conductor is almost non-existent.
The working voltage range of the zener diode starts from 3.3; 4.7; 5.1; 6.2; 6.8; 9.1; 10; 11; 12; 13; 15 to 200 Volts.
2. Silicon Control Rectifier (SCR)
SCR symbol
Silicon Control Rectifier (SCR) is a semiconductor component used as a switch / switch conditions for SCR to work in addition to the voltage is met, namely it can also be with a trigger or trigger on the gate, the following is the symbol of SCR. Here is a picture of how it works:
Trigger SCR
Note:
- Trigger current when sending = 0.45 mA
- Between node and cathode = 0.5 s/d 0.7 V
- Holding current (flowing between the anode and cathode = 0.1mA to 85mA.
3. LED (Light Emitting Diode)
LED (light emiting dioda) Family
It is a kind of function diode that can emit light if it gets forward current. LED requires a working voltage between 1.5V -- 2.5V and a current between 5mA-20mA.
The shapes are varied, from small to large and only withstand forward bias voltages of 1.5V to 2.5 Volts. But recently the latest LED technology has support for 3 Volts.
LED symbol
Common damage that often occurs to diodes including LEDs is:
- Break between the anode and cathode.
- Connected between the anode and cathode legs
- Leakage between the anode and cathode.
The basic materials of LED are:
- Gallium Arsenide (GaAs) emits infrared light
- Gallium Arsenide phosphide (GaAsP) emits a yellow color
- Gallium Phospide (GaP) emits red or green color
Testing Diodes
When Diode Gets Forward Voltage/Current
When Diode Gets Reverse Voltage/Current
- Place the selector switch in the ohm meter (range) position.
- Attach the red (+) plug to the cathode pole, and the black (-) plug to the anode pole.
- If the needle moves it means the diode is good and if the needle is still then the diode is broken.
- Then turn it over, the (+) connector gets the anode and the (-) connector gets the cathode.
- If the needle is still, it means the diode is good and if the needle moves it means the diode is damaged.