Two-color fault indicator with programmable alarm current value

Abstract

The invention relates to an alarm current value settable bi-color fault indicator which comprises an alarm current setting switch, a current sensing element, a signal conditioning circuit, a processing unit and an optical signal generating circuit, wherein the current sensing element, the signal conditioning circuit, the processing unit and the optical signal generating circuit are sequentially and electrically connected in the signal transmitting direction. The processing unit comprises an A / D converter for digitalizing voltage signals output by the signal conditioning circuit, a comparator for comparing voltage signals, judging whether the voltage signals exceed a set awakening threshold value and then triggering and awakening a CPU if the voltage signals exceed the set awakening threshold value, and the CPU for controlling work of the A / D converter, calculating a digitalization result of the A / D converter and sending a fault indication control signal if the digitalization result shows that a fault is produced, wherein the control signal triggers the optical signal generating circuit to send an optical signal and give an alarm indication. The alarm current value settable bi-color fault indicator has the LED indication advantages of being high in accuracy, low power consumption, capable of achieving accurate multi-gear setting of alarm current values and various in output mode, and a user can perform flexible setting according to line load current level.

Description

technical field [0001] The invention relates to an electrical fault indicator, in particular to a fault indicator whose alarm current value can be set. Background technique [0002] In the electrical system, fault indicators are usually used to detect electrical faults such as short circuit, grounding, and open circuit in the distribution network lines of the system and give alarm indications. Generally, the current value of the line is detected by the current sensor. When the current of the detected line An alarm indication is issued when the value is outside the normal range. Such as figure 1 As shown, most of the current sensors in the prior art are analog current sensors, and the alarm threshold is set in the analog trigger circuit. Adjustable, so as to change the alarm threshold, but this adjustment is difficult to grasp whether the resistance value of the potentiometer connected to the circuit after adjustment is the value you really want to set, resulting in low acc...

AI Technical Summary

Problems solved by technology

like figure 1 As shown, most of the current sensors in the prior art are analog current sensors, and the alarm threshold is set in the analog trigger circuit. Adjustable, so as to change the alarm threshold, but this adjustment is difficult to grasp whether the resistance value of the potentiometer connected to the circuit after adjustment is the value you really want to set, resulting in low accuracy and precision of alarm threshold adjustment, which is easy to cause In the case of the alarm, there is no alarm and false alarm when it should not be alarmed

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