Ia protection grade intrinsically safe power supply circuit with constant voltage output for coal mine

Abstract

The invention discloses an ia protection grade intrinsically safe power supply circuit with constant voltage output for a coal mine. The circuit comprises an isolation type power supply conversion circuit (1), a current limiting circuit (2), an overvoltage protection circuit (4) which are connected in sequence and a first voltage feedback control circuit (5) and a second voltage feedback control circuit (6), wherein the input end of the isolation type power supply conversion circuit (1) is connected to an input power supply, the output end of the isolation type power supply conversion circuit(1) is connected to the input end of the current limiting circuit (2), the output end of the current limiting circuit (2) is connected to a load, and the current limiting circuit (2) is used for limiting current output to a load. High-power constant-voltage output of the ia protection grade intrinsically safe power supply within a certain load range is realized, and the problem that the load capacity of the traditional ia protection grade intrinsically safe power supply is seriously insufficient is better solved.

Description

technical field [0001] The invention belongs to the field of explosion-proof electrical and electronic circuit design in coal mines, and relates to an intrinsically safe power supply circuit for coal mines with constant voltage output and ia protection level. Background technique [0002] The underground coal mine is an explosive and dangerous environment such as gas and coal dust. Intrinsically safe power supplies are widely used in various electronic equipment, measuring instruments, control instruments and electrical transmission equipment in coal mines. According to the relevant requirements of GB3836, the electrical equipment used in the environment should generally have the "ib" protection level, while the power supply placed in the gas drainage pipeline and associated with the gas transportation monitoring system and other equipment should reach the ia protection level. Intrinsically safe circuits in electrical equipment with protection level ia require that they shou...

AI Technical Summary

Problems solved by technology

This traditional ia protection level intrinsically safe power supply is limited by the necessary protection methods, the current limiting resistor causes a large amount of power loss, and its output characteristics are linear (such as Figure 4 shown), that is, the voltage delivered to the terminal drops sharply as the load increases, and the load capacity is seriously insufficient

Images