CN2760569Y - Grounding monitor - Google Patents

Abstract

The utility model relates to a grounding monitor. The utility model comprises an input sampling circuit carrying out sampling to voltage difference generated when the ground fault of a circuit happens, a voltage comparing circuit for comparing the output voltage signals of the input sampling circuit with a setting voltage, a pre-alarm indication circuit connected with the output end of the voltage comparing circuit, a time delay circuit connected with the output end of the voltage comparing circuit and a grounding alarm circuit connected with the output end of the time delay circuit. The utility model can be totally used in direct currents, alternating currents and three-phase ungrounded feeding systems to accurately separate a specific circuit which generates the ground fault.

Description

Grounded Monitor

Technical field

The utility model relates to a kind of Grounded Monitor that ground connection is reported to the police.

Background technology

In the prior art, in direct current or AC two-conductor system and the earth-free feed system of three-phase, reason generation earth fault jeopardizes safety because the bus insulation against ground is aging etc. often, therefore must implement persistent surveillance to its feeder line.

Existing in the market corresponding device thereof is in operation, similar have insulating monitoring relay, insulation monitoring device, a Grounded Monitor etc., but all there is defective in prior art in varying degrees, if any the insulation monitoring device only can be used in direct current two-wire system feed system, and ceiling voltage only reaches 300V/DC, and different electric pressures can not be compatible; The line insulation situation is to reflect by the digital watch of indicating leakage current value in addition, this kind method can only be used for one of two buses and thoroughly do away with edge decline, another thoroughly does away with the good situation of edge, otherwise when two bus insulation resistance all descend, then can't correctly reflect.The Grounded Monitor usable range that has has enlarged, in direct current or AC two-conductor system and the earth-free feed system of three-phase, all can use, the voltage that is monitored circuit is also from direct current 24V-880V, exchange 50HZ, 24V-600V, but the problem of this class monitor maximum is can in time send alerting signal when earth fault takes place, but can't specifically distinguish the circuit place of breaking down, this brings certain difficulty for the timely earth fault of getting rid of.

Summary of the invention

Technical scheme of the present invention is: a kind of Grounded Monitor, is used for the voltage comparator circuit that the voltage signal of input sampling circuit output is compared with setting voltage, the pre-alarm indication that is connected with the output terminal of described voltage comparator circuit, the delay circuit that is connected with the output terminal of described voltage comparator circuit, the grounding alarm circuit that is connected with the output terminal of described delay circuit at the input sampling circuit that the voltage difference that produces when comprising circuit generation earth fault is taken a sample.

The utility model compared with prior art has following advantage:

All can use in the earth-free feed system of direct current or interchange and three-phase, can accurately distinguish the concrete circuit that earth fault takes place, the voltage that is monitored circuit also can be at direct current 24V-880V, exchange in 50HZ, the 24V-1000V scope, actual needs according to the user is made adjustment, and need not to change hardware.

Description of drawings

Accompanying drawing 1 is the utility model circuit block diagram;

Accompanying drawing 2 is circuit theory diagrams of the present utility model;

Embodiment

Referring to accompanying drawing 1, a kind of Grounded Monitor, the input sampling circuit 1 that the voltage difference that produces when comprising circuit generation earth fault is taken a sample, the voltage comparator circuit 2 that is used for the voltage signal of input sampling circuit 1 output is compared with setting voltage, the pre-alarm that is connected with the output terminal of described voltage comparator circuit 2 indicate 5, the delay circuit 3 that is connected with the output terminal of described voltage comparator circuit 2, the grounding alarm circuit 4 that is connected with the output terminal of described delay circuit 3.Referring to accompanying drawing 2, the input end of described input sampling circuit 1 is serially connected with the bridge rectifier circuit of four diode D1, D2, D3, D4 composition.Pre-alarm indication 5 comprises LED 1 and triode Q1.Form integrator delay-time circuit by resistance R 2, capacitor C 2, this integrator delay-time circuit and comparer U2 form delay circuit 3 jointly, after the voltage sample of input sampling circuit 1 continues about 10 seconds, U2 exports high level, then bidirectional triode thyristor Q2 conducting, make relay K 1 conducting in the grounding alarm circuit 4, output alarm signal, and by LED 2 luminous warnings.

Claims (2)

1, a kind of Grounded Monitor, the grounding alarm circuit [4] that the input sampling circuit [1] that the voltage difference that produces when comprising circuit generation earth fault is taken a sample, the voltage comparator circuit [2] that is used for the voltage signal of input sampling circuit [1] output is compared with setting voltage, the pre-alarm that is connected with the output terminal of described voltage comparator circuit [2] are indicated [5], the delay circuit [3] that is connected with the output terminal of described voltage comparator circuit [2], are connected with the output terminal of described delay circuit [3].

2, Grounded Monitor according to claim 1 is characterized in that: the input end of described input sampling circuit [1] is serially connected with the bridge rectifier circuit of four diode D1, D2, D3, D4 composition.

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