Current output power distribution switching circuit

Abstract

The invention discloses a current output power distribution switching circuit which overcomes the problems in the prior art that the current active and passive output functions cannot be simultaneously met; a device is actively broken by backward flowing, meanwhile, a signal cannot be normally transmitted due to passivity, or ports need to be added, and the positive and negative signal lines needto be exchanged during internal and external power distribution. The current output power distribution switching circuit adopts an internal power supply, a function selection switch, a current limiting module and a feedback module which are connected in sequence, the input end of the current limiting module is connected with a guide module, and the function selection switch is a controlled electromagnetic switch linked with a detection switch; the detection switch is further connected with a logic judgment module for judging the power supply condition, and an either-or function selection switch is used, so that the output requirements are met simultaneously, the circuit is simple, and the functions are complete. A diode is used for controlling the direction of current in the circuit, anda reverse connection preventing function is achieved, so that the circuit safety is guaranteed. Whether the circuit is active or passive inside and outside simultaneously is judged, so that the manualerrors are avoided, and the reliability is improved.

Description

technical field [0001] The invention relates to the field of power distribution, in particular to a current output power distribution switching circuit. Background technique [0002] For instruments with AO current output function (usually 4~20mA standard signal), such as isolator, recorder, PLC, etc., due to the variety of equipment or measurement equipment (such as DCS system, PLC, actuator, etc.) on the current input side , complicated, and there is no unified standard, often encounter the problem of who will provide the power supply for the AO current output. From the point of view of field application, most of the cases are provided by the current output module itself, that is to say, as a current signal source, it outputs a standard 4~20mA current signal; but sometimes the current input side already has a power supply, which needs to be provided by the current output device A 4~20mA passive signal is usually called LOOP measurement. If the input and output devices ar...

AI Technical Summary

Problems solved by technology

[0004] The present invention mainly solves the problem that the original technology cannot satisfy current active and passive output functions at the same time, or needs to increase ports, and needs to exchange positive and negative signal lines when internal and external power distribution; provides a current output power distribution switching circuit that can simultaneously meet Active and passive output functions of current signals, without adding ports, without exchanging positive and negative signal lines during internal and external power distribution, with anti-reverse connection protection function, high reliability

The present invention also solves the problem in the prior art that both inside and outside are active at the same time, and the equipment will be reversed and broken, and at the same time, passive will cause the signal to fail to transmit normally; it provides a current output power distribution switching circuit, which can detect whether the inside and outside are active or not at the same time. source, automatically switching to the correct circuit

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