Device for preventing electric current backward flowing and output capacitor discharging

Abstract

The invention relates to a device for preventing electric current backward flowing and output capacitor discharging. The output end of a rectification unit is connected with a filtering unit, the output positive end of the filtering unit is connected with a backward-flowing prevention diode and an output control switch, the output control switch is connected with a voltage reduction circuit, and a cathode of the backward-flowing prevention diode is connected with a voltage detection branch, a switch and a large capacitive load; one end of the voltage detection branch is located at the front end of the large capacitive load, one end of a sampling branch is connected with the rear end of the large capacitive load, the other end of the voltage detection branch and the other end of the sampling branch are connected to a control circuit unit, the control circuit unit is connected with the switch and the output control switch in a control mode, the other end of the switch is connected with a booster circuit, the booster circuit and the voltage reduction circuit are connected with a high-voltage energy-storage capacitor, and the control circuit unit, the filtering unit, the booster circuit, the voltage reduction circuit and the high-voltage energy-storage capacitor are grounded. Energy flowing backwards from a load capacitor is rapidly absorbed and stored, the energy is rapidly released to an output capacitor when the device needs charging, and the on-off state of a main circuit and an energy storing circuit is controlled synchronously through an MCU.

Description

technical field [0001] The invention relates to an output capacitor energy recovery device when a large-capacitance load power supply is switched on and off quickly, in particular to a device for preventing current backfeeding and output capacitor discharge. Background technique [0002] At present, the DC power supply converts the mains power into a constant or variable DC voltage, and can adjust the output voltage and current limit to supply power to the load. In order to maintain the stability of the output voltage, many large-capacity electrolytic capacitors are generally connected in parallel at the output end. When the load current is small, the energy stored in the output capacitor takes a long time to be released. If it is necessary to switch the power supply quickly to obtain a square wave output voltage, the internal components of the power supply need to dissipate the energy on the capacitor. In general, an anti-reverse diode is connected to the output of the po...

AI Technical Summary

Problems solved by technology

If you need to switch the power supply quickly to get a square wave output voltage, you need the internal components of the power supply to consume the energy on the capacitor

In general, an anti-reverse diode is connected to the output of the power supply to prevent the current from pouring back, so that the energy on the capacitor cannot be consumed through the internal components of the power supply. As a result, the voltage on the capacitor cannot be released, and a square wave output cannot be obtained. , In addition, many devices also have the requirement of shutdown and discharge time, and such a design cannot meet this requirement

Some designs use dead load to consume energy, which not only loses a lot of energy, but also has poor effect when the capacitance is large.

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