Program control AC constant current source system

Abstract

The invention relates to a program control AC constant current source system, and the system comprises a constant current source circuit module. A single-chip microcomputer unit of the constant current source circuit module outputs two complementary pulse width modulation drive signals for controlling a DC-AC full-bridge inverter circuit, and carries out the time sequence control of the two complementary pulse width modulation drive signals. The output end of a DC conversion module is connected with the DC-AC full-bridge inverter circuit, and the output end of the DC-AC full-bridge inverter circuit is connected with a filter circuit. A current-increasing transformer carries out the voltage reduction and current increasing of a high-voltage small current outputted by the filter circuit, and then supplies the high-voltage small current to a load circuit. A voltage-adjusting type self-coupling transformer is located between the constant current source circuit module and the current-increasing transformer, and the duty ratios of the pulse width modulation drive signals are mainly controlled to be 20%-80% through changing the number of turns of a secondary coil of the voltage-adjusting type self-coupling transformer. The system also comprises a current feedback circuit module for detecting the size of a current of the load circuit. The system is high in response speed and is high in precision.

Description

technical field [0001] The invention relates to a power supply system, specifically a program-controlled AC constant current source system. Background technique [0002] The constant current source is also called the current source and the steady current source, and it is a standard 50HZ high-precision AC steady-current power supply. During the factory inspection of thermal relays and intelligent circuit breakers in low-voltage electrical appliances, they need to be tested with constant power frequency alternating current (50Hz in China). The traditional traditional test uses a power transformer in series with a high-power resistor, adjusts the voltage according to the load resistance, and obtains the corresponding test current, which has problems such as poor accuracy and slow adjustment speed. Contents of the invention [0003] Purpose of the present invention: To overcome the defects of the prior art, the present invention provides a program-controlled AC constant curr...

AI Technical Summary

Problems solved by technology

The traditional traditional test uses a power transformer in series with a high-power resistor, adjusts the voltage according to the load resistance, and obtains the corresponding test current, which has problems such as poor accuracy and slow adjustment speed.

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