Devices to prevent current backfeeding and output capacitor discharge

Abstract

The invention relates to a device for preventing current backfeeding and output capacitor discharge. The output terminal of the rectification unit is connected with the filter unit, the positive output terminal of the filter unit is connected with an anti-backfeed diode and an output control switch, the output control switch is connected with a step-down circuit, and the anti-backfeed diode The cathode is connected to the voltage detection branch, switch and large capacitive load, one end of the voltage detection branch is located at the front end of the large capacitive load, one end of the sampling branch is connected to the back end of the large capacitive load, the other end of the voltage detection branch is connected to the other end of the sampling branch Connected to the control circuit unit, the control circuit unit is connected to the switch and the output control switch, the other end of the switch is connected to the boost circuit, the boost circuit and the step-down circuit are connected to the high-voltage energy storage capacitor, the control circuit unit, the filter unit, and the boost circuit , the step-down circuit and the high-voltage energy storage capacitor are grounded. Quickly absorb and store the energy poured back from the load capacitor, and quickly release the energy to the output capacitor when charging is required. The MCU synchronously controls the on-off status of the main circuit and the energy storage circuit.

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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