What are the applications of diode principles?
As we all know, diodes have the characteristic of unidirectional conduction, which can be applied in these areas:
1. Rectification
Rectifier diodes are mainly used in rectifier circuits, which convert alternating current into direct current. The pulsating rectifier diodes are all surface junction types, so the junction capacitance is large, resulting in a lower operating frequency, generally less than 3Hz.
2. Switching
Under the action of direct current voltage, the diode has a small resistance and is in a conducting state, equivalent to a closed switch; under the action of reverse voltage, the resistance is very large, and it is in an open state, like an open switch. Utilizing the switching characteristics of diodes, various logic circuits can be formed.
3. Limiting
After the diode conducts in the forward direction, its forward voltage drop remains basically unchanged (0.7V for silicon diodes, 0.3V for germanium diodes). Using this characteristic, it can serve as a limiting component in circuits, restricting the signal amplitude within a certain range.
4. Continuation
It plays a continuation role in inductive loads such as switch power supplies and relays.
5. Detection
The main function of detection diodes is to detect low-frequency signals in high-frequency signals. Their structure is point contact type. Its junction capacitance is small, and the operating frequency is high, so they are generally made of germanium.
6. Damping
Damping diodes are commonly used in high-frequency voltage circuits, capable of withstanding higher reverse breakdown voltages and larger peak currents. They are often used in television circuits, with common types including 2CN1, 2CN2, and BSBS44.
7. Display
Used in displays such as VCD, DVD, and calculators.
8. Voltage Stabilization
This type of tube is made using the reverse breakdown characteristics of diodes, and the voltage across the tube remains basically unchanged in the circuit, serving the purpose of voltage stabilization. Common voltage stabilizing tubes include 2CW55, 2CW56, etc.
9. Triggering
Trigger diodes, also known as bidirectional trigger diodes (DIAC), are a type of symmetrical three-layer structure bipolar semiconductor device. They are commonly used to trigger bidirectional thyristors; used for over-voltage protection in circuits, etc.
