Principle of high-frequency power supply
Main circuit
The entire process of input and output from the AC power grid, including: 1. Input filter: Its function is to filter out the clutter existing in the power grid, while also hindering the feedback of the generated clutter to the public power grid. 2. Rectification and filtering: Directly rectifying the AC of the power grid into smoother DC power for the next level of transformation. 3. Inversion: Transforming rectified direct current into high-frequency alternating current, which is the core part of high-frequency. The higher the frequency, the smaller the ratio of volume, weight, and output power. 4. Output rectification and filtering: Provide stable and reliable DC power supply according to load requirements.
control circuit
On the one hand, samples are taken from the output end, compared with the set standard, and then the inverter is controlled to change its frequency or pulse width to achieve stable output. On the other hand, based on the information provided by the test circuit and identified by the protection circuit, control circuits are provided to provide various protection measures for the entire machine.
Detection circuit
In addition to providing various operating parameters in the protection circuit, various display instrument data are also provided.
Auxiliary power supply
Provide different required power supplies for all single circuits. Switch control voltage stabilization principle Switch K is repeatedly turned on and off at a certain time Spaced repetition. When switch K is turned on, input power E is supplied to load RL through switch K and filter circuit. During the whole switch on period, power E provides energy to load; When switch K is disconnected, input power E interrupts the supply of energy. It can be seen that the input power supply provides energy to the load intermittently. In order for the load to receive continuous energy supply, the switch regulated power supply must have an energy storage device that stores a portion of the energy when the switch is turned on, and releases it to the load when the switch is turned off. In the figure, the circuit composed of inductor L, capacitor C2, and diode D has this function. Inductance L is used to store energy. When the switch is disconnected, the energy stored in inductance L is released to the load through diode D, so that the load can obtain continuous and stable energy. Because diode D makes the load current continuous, it is called Flyback diode. The average voltage EAB between AB can be represented by the following equation: EAB=TON/T * E, where TON is the time each switch is turned on, and T is the working cycle of the switch on/off (i.e. the sum of the switch on time TON and off time TOFF). From the equation, it can be seen that changing the ratio of switch on time and working cycle also changes the average voltage between AB. Therefore, automatically adjusting the ratio of TON and T with changes in load and input power voltage can maintain the output voltage V0 unchanged. Changing the on time TON and duty cycle ratio, also known as changing the duty cycle of the pulse, is a method called "Time Ratio Control" (TRC).
