The working principle and classification of linear power sources
A linear power supply is an electronic device that converts alternating current into stable direct current. Its basic working principle is to use a transformer to reduce AC voltage and rectify it into DC power, and then stabilize the DC power at the required voltage level through a voltage stabilizing circuit.
Specifically, the working principle of a linear power supply includes the following steps:
Transformer voltage reduction: The input AC power is reduced through a transformer, usually using a large inductance coil and an iron core magnetic core to reduce the input voltage to the desired level.
Rectification: Converts the reduced AC power into DC power, usually using a rectification circuit, such as a single-phase or three-phase rectifier bridge, to convert the AC signal into a unidirectional DC signal.
Filter: Filter direct current through components such as capacitors to remove pulsating components in direct current and obtain more stable direct current electrical signals.
Voltage regulation: Use voltage regulation devices such as diodes, transistors, integrated circuits, etc. to regulate the DC voltage to ensure the stability of the output voltage.
Output: Output stable direct current to the device that needs to be used.
It should be noted that the output voltage of a linear power supply usually has a certain relationship with the input voltage. For example, the output voltage is equal to the input voltage minus a certain voltage drop, so it needs to be adjusted and designed according to specific requirements.
Linear power sources can be classified in different ways, and the following are common ways to classify linear power sources:
According to the type of input power supply, it can be divided into AC input type and DC input type. The AC input type usually requires an external transformer to convert AC power into the required DC voltage. The DC input type can directly accept DC power input.
According to the characteristics of output voltage and current, it can be divided into constant voltage type and constant current type. The output voltage of a constant voltage linear power supply is stable, and the output current can change according to load changes. The output current of a constant current linear power supply is stable, and the output voltage changes with the load.
According to the voltage regulation method, it can be divided into ordinary voltage regulation type and open loop voltage regulation type. The ordinary voltage regulator uses feedback circuits to control output voltage stability, requiring the use of voltage regulator devices such as transistors, diodes, integrated circuits, etc. The open-loop voltage regulator type does not have a feedback circuit and usually uses methods such as potentiometers to adjust the output voltage. The output voltage stability is poor, but the cost is lower.
According to power level, it can be divided into low power type and high power type. Low power models generally have low output power and are suitable for supplying power to small electronic devices, such as mobile power supplies, audio devices, etc. The high-power type is suitable for the power supply of large electronic equipment, such as industrial equipment, robots, machine tools, etc.
According to the application field, it can be divided into general and specialized types. The universal model is suitable for various electronic devices, such as computers, mobile phones, digital cameras, etc. Specialized models are suitable for specific fields, such as medical equipment, military equipment, etc.
