CN104965146A

CN104965146A - Short circuit detector

Info

Publication number: CN104965146A
Application number: CN201510329773.9A
Authority: CN
Inventors: 王志
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-06-15
Filing date: 2015-06-15
Publication date: 2015-10-07

Abstract

The present invention provides a short circuit detector, characterized by comprising a 3V DC power supply, a detected input circuit, a bridge balancing circuit, and a sound prompt circuit. A professional short circuit/circuit break detector has the problems of high price, uneasy popularization in the working fields of cable maintenance and electrician, and so on. The short circuit detector of the present invention can compensate and overcome the defects, and can detect short circuit situations of a circuit in the process of installing, debugging and maintaining electron equipment, thus the short circuit detector is a practical tool which is low in price, convenient in use, reliable in detection result and easy in popularization, and is suitable for batch development of factories.

Description

Short circuit detector

Technical field

The invention belongs to electronics and technical field of electrical measurement, relate to a kind of short circuit detector.

Background technology

It is the problem often run in electric circuit inspection process that short circuit/open circuit detects, but sometimes detects to get up to waste time and energy.For automobile circuit, more often that fault is detected, the particularly short interruption fault of automobile, and this kind of fault detect is got up very difficult, even if experienced maintenance personal also roughly can only judge some position, finally also to remove " taking off " this section of circuit, and if unfamiliar maintenance personal, then can only the effort of one one go " smoothing out with the fingers ", short circuit/open circuit detector is special in detecting the special detector that various circuit is developed.

But professional short circuit/open circuit detector have price high, in the career field such as maintaining cables and electrician the not easily problem such as universal, short circuit detector of the present invention can make up and overcome these defects, it can also be installed at electronic equipment, debug and in maintenance process, the short-circuit conditions of testing circuit, it is that a kind of price is low, easy to use, testing result reliable, is easy to universal utility.

Below describe in detail short circuit detector of the present invention necessity involved in implementation process, guardian technique content.

Summary of the invention

Goal of the invention and beneficial effect: professional short circuit/open circuit detector have price high, in the career field such as maintaining cables and electrician the not easily problem such as universal, short circuit detector of the present invention can make up and overcome these defects, it can also be installed at electronic equipment, debug and in maintenance process, the short-circuit conditions of testing circuit, it is that a kind of price is low, easy to use, testing result reliable, is easy to universal utility, is suitable for factory's batch exploitation.

Circuit working principle: detection probe TX1, between detection probe TX2 and circuit-under-test resistance composition input stage, form bridge balance circuit by NPN transistor VT1, VT2 and resistance R2 ~ R7.Sound prompting circuit is formed by elements such as NPN transistor VT3 and hummer HA.

When short circuit detector detects short circuit, hummer HA sounds, the control that hummer HA exports by NPN transistor VT2; When tested input resistance is greater than 10 Ω, NPN transistor VT2 conducting, its collector potential is close to zero, hummer HA no audio signal, when input resistance is enough low, NPN transistor VT2 is ended, NPN transistor VT3 obtains biased, drive hummer HA to pipe, the hummer HA frequency that pipes selects 1200Hz to be advisable.

Technical characteristic: short circuit detector, it comprises 3V direct supply, tested input circuit, bridge balance circuit, auditory tone cues electric circuit, it is characterized in that:

Tested input circuit: it is made up of detection probe TX1, detection probe TX2, resistance R1 and germanium diode D1, the non-test side of detection probe TX1 connects germanium diode D1 positive pole by resistance R1, the non-detection termination germanium diode D1 negative pole of detection probe TX2 and circuit ground GND;

Bridge balance circuit: it is by NPN transistor VT1, NPN transistor VT2, resistance R2 ~ resistance R7 forms, one end of the emitter connecting resistance R2 of NPN transistor VT1 and germanium diode D1 positive pole, the collector of NPN transistor VT1 is by resistance R3 connection circuit positive pole VCC, the base stage of NPN transistor VT1 connects the base stage of NPN transistor VT2 and one end of resistance R4, the other end connection circuit positive pole VCC of resistance R4, the collector of NPN transistor VT2 is by resistance R5 connection circuit positive pole VCC, one end of emitter connecting resistance R6 of NPN transistor VT2 and one end of resistance R7, the other end connection circuit positive pole VCC of resistance R6, the other end connection circuit ground GND of resistance R7,

Auditory tone cues electric circuit: it is made up of resistance R8, NPN transistor VT3 and hummer HA, the base stage of NPN transistor VT3 connects the collector of NPN transistor VT2 by resistance R8, the collector of NPN transistor VT3 connects the negative pole of hummer HA, the emitter connection circuit ground GND of the positive pole connection circuit positive pole VCC of hummer HA, NPN transistor VT3;

The positive pole of 3V direct supply passes through keyswitch AN connection circuit positive pole VCC, the non-test side of the negative pole connection circuit ground GND and detection probe TX2 of 3V direct supply.

Accompanying drawing explanation

Accompanying drawing 1 is short circuit detector provided by the invention embodiment circuit working schematic diagram.

Embodiment

According to the short circuit detector circuit fundamental diagram shown in accompanying drawing 1 and accompanying drawing explanation, and according to annexation between components and parts in each several part circuit described in summary of the invention, and components and parts technical parameter described in embodiment requires and circuit production main points are carried out enforcement and can be realized the present invention, is further described correlation technique of the present invention below in conjunction with embodiment.

The technical parameter of components and parts and selection requirement

VT1 ~ VT3 is NPN transistor, and the model that 3 NPN transistor are selected is 2SC9013;

D1 is germanium diode, and the model selected is 1N60;

Resistance all selects the carbon resister of 1/8W, the resistance of resistance R1 is 5.1 Ω, the resistance of resistance R2 is 4.3K Ω, the resistance of resistance R3 is 22K Ω, the resistance of resistance R4 is 22K Ω, and the resistance of resistance R5 is 4.3K Ω, and the resistance of resistance R6 is 4.3K Ω, the resistance of resistance R7 is 220 Ω, and the resistance of resistance R8 is 27K Ω;

HA is hummer, selects hummer to be built-in with sound signal circuit for generating, and operating voltage is 3V;

Detection probe TX1 and detection probe TX2 uses red test pencil and the black meter pen of common multimeter respectively;

DC is 3V direct supply, can use 2 joint No. 5 alkaline batteries.

Circuit production main points and circuit debugging

Because the circuit structure of short circuit detector is fairly simple, as long as the electronic devices and components performance generally selected is intact, and the components and parts annexation to specifications in accompanying drawing 1 is welded, physical connection line and welding quality are through carefully checking correctly, and circuit of the present invention does not need to carry out debugging and can normally work;

Circuit components layout of the present invention, circuit structure design, its shape and size etc. of outward appearance are not all gordian techniquies of the present invention; neither application claims protection guardian technique content; because not affecting specific implementation process of the present invention, therefore do not illustrate one by one in the description.

Claims

1. a short circuit detector, it comprises 3V direct supply, tested input circuit, bridge balance circuit, auditory tone cues electric circuit, it is characterized in that:

Described tested input circuit is made up of detection probe TX1, detection probe TX2, resistance R1 and germanium diode D1, the non-test side of detection probe TX1 connects germanium diode D1 positive pole by resistance R1, the non-detection termination germanium diode D1 negative pole of detection probe TX2 and circuit ground GND;

Described bridge balance circuit is by NPN transistor VT1, NPN transistor VT2, resistance R2 ~ resistance R7 forms, one end of the emitter connecting resistance R2 of NPN transistor VT1 and germanium diode D1 positive pole, the collector of NPN transistor VT1 is by resistance R3 connection circuit positive pole VCC, the base stage of NPN transistor VT1 connects the base stage of NPN transistor VT2 and one end of resistance R4, the other end connection circuit positive pole VCC of resistance R4, the collector of NPN transistor VT2 is by resistance R5 connection circuit positive pole VCC, one end of emitter connecting resistance R6 of NPN transistor VT2 and one end of resistance R7, the other end connection circuit positive pole VCC of resistance R6, the other end connection circuit ground GND of resistance R7,

Described auditory tone cues electric circuit is made up of resistance R8, NPN transistor VT3 and hummer HA, the base stage of NPN transistor VT3 connects the collector of NPN transistor VT2 by resistance R8, the collector of NPN transistor VT3 connects the negative pole of hummer HA, the emitter connection circuit ground GND of the positive pole connection circuit positive pole VCC of hummer HA, NPN transistor VT3;

The positive pole of described 3V direct supply passes through keyswitch AN connection circuit positive pole VCC, the non-test side of the negative pole connection circuit ground GND and detection probe TX2 of 3V direct supply.