CN203396874U

CN203396874U - Low-capacity capacitor tester

Info

Publication number: CN203396874U
Application number: CN201320555559.1U
Authority: CN
Inventors: 黄月华
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-09-09
Filing date: 2013-09-09
Publication date: 2014-01-15
Anticipated expiration: 2023-09-09

Abstract

The utility model provides a low-capacity capacitor tester characterized by comprising a 3V DC power source, a like-polarity Darlington circuit, a display circuit and a testing port. The specification of three NPN-type triodes (VT1, VT2,VT3) in the like-polarity Darlington circuit is 2SC9013. A capacitor having capacitance that is lower than 0.01 microfarad is difficult to measure by using a common universal meter. Although a plurality of methods can be adopted for measuring the small-capacity capacitor, the most convenient method is adopting a digital capacitance meter. However, a special capacitance measuring instrument is unaffordable for general workers in electric fields or electric product amateurs. In order to meet general requirements for measuring the low-capacitor capacitor, the low-capacity capacitor tester provided by the utility model employs the like-polarity Darlington triodes for reducing requirements for drive power of devices and general performance of the low-capacity capacitor can be judged through lighting condition of a light emitting diode.

Description

Low capacity capacity measuring set

Technical field

The utility model belongs to electronic component field of measuring technique, is about a kind of low capacity capacity measuring set.

Background technology

With common multimeter, be difficult to the electric capacity of test capacity below 0.01 μ F, although test low capacity electric capacity has several different methods, but, should use the most easily digital capacitance meter test, but professional capacitance measuring instrument is all difficult to be equipped with for general electronic working personnel or amateurish electrophile.In order to solve the requirement of low capacity electric capacity general measure, the circuit of low capacity capacity measuring set described in the utility model is used same polarity Darlington triode, be in order significantly to reduce the requirement of device to driving power, utilize lumination of light emitting diode whether to judge the cardinal principle performance of low capacity electric capacity.

Below describe low capacity capacity measuring set described in the utility model related relevant technologies content in implementation process in detail.

Utility model content

Goal of the invention and beneficial effect: with common multimeter, be difficult to the electric capacity of test capacity below 0.01 μ F, although test low capacity electric capacity has several different methods, but, should use the most easily digital capacitance meter test, but professional capacitance measuring instrument is all difficult to be equipped with for general electronic working personnel or amateurish electrophile.In order to solve the requirement of low capacity electric capacity general measure, the circuit of low capacity capacity measuring set described in the utility model is used same polarity Darlington triode, be in order significantly to reduce the requirement of device to driving power, utilize lumination of light emitting diode whether to judge the cardinal principle performance of low capacity electric capacity.

Circuit working principle: the circuit of low capacity capacity measurement is to utilize lumination of light emitting diode whether to judge the quality of low capacity electric capacity.NPN type triode VT1 in circuit theory diagrams～VT3 forms same polarity Darlington compositing amplification tube, and the enlargement factor of circuit is the product of 3 triode enlargement factors.When the red test pencil TX1 of low capacity capacity measuring set, black meter pen TX2 hand capacity two ends, just there is the charging current testing capacitance of flowing through, although this charging current is very small, through the Darlington triode VT1～VT3 of high-amplification-factor, amplify metapedes to drive LED to be lit.If LED is not luminous, represent that electric capacity is without charging ability, the inner broken string of measured capacitance is described or damages.

Technical characterictic: low capacity capacity measuring set, it comprises 3V direct supply, same polarity Darlington circuit and display circuit, test interface, it is characterized in that:

Same polarity Darlington circuit and display circuit: it is comprised of 3 NPN type triode VT1～VT3, the emitter of NPN type triode VT1 connects the base stage of NPN type triode VT2, the emitter of NPN type triode VT2 connects the base stage of NPN type triode VT3, the emitter connection circuit ground GND of NPN type triode VT3, the anodal VCC of collector connection circuit of the collector of NPN type triode VT1 and NPN type triode VT2, the collector of NPN type triode VT3 connects the negative pole of LED, the anodal VCC of anodal connection circuit of LED;

Test interface: the anodal VCC of red test pencil TX1 connection circuit, black meter pen TX2 connects the base stage of NPN type triode VT1 by resistance R 1;

The anodal VCC of anodal connection circuit of 3V direct supply, the negative pole connection circuit ground GND of 3V direct supply.

Accompanying drawing explanation

Accompanying drawing is the embodiment circuit working schematic diagram that the utility model provides a low capacity capacity measuring set.

Embodiment

According to low capacity capacity measuring set circuit working schematic diagram shown in the drawings and accompanying drawing explanation, and according to annexation between components and parts in the each several part circuit described in utility model content, and the components and parts technical parameter described in embodiment requires and circuit production main points are implemented to realize the utility model, below in conjunction with embodiment, correlation technique of the present utility model is further described.

Components and parts are selected and technical parameter

In circuit, the model of 3 NPN type triode VT1～VT3 is: 2SC9013, requires β value >=150 of 3 NPN type triode VT1～VT3, and require penetrating current less better;

R1 is resistance, selects RTX-1/8W type carbon resister, and its resistance is 12K Ω;

LED is light emitting diode, selects red super bright light emitting diode;

3V direct supply can save No. 5 manganese-zinc batteries with two;

The test pencil that red test pencil TX1, black meter pen TX2 can be used common universal electric meter to use.

Circuit production main points, circuit debugging and using method

Low capacity capacity measuring set, when not using, does not consume electric energy substantially, so low capacity capacity measuring set needn't arrange power switch;

The element using due to low capacity capacity measuring set circuit seldom, thereby put into all components and parts in plastic casings by available small-sized circuit board.Just can be luminous at tester outside tape insulation layer conductor 220V alternating current 1.5cm, require tester more far better apart from the distance of computer CRT display screen;

Because low capacity capacity measuring set has higher measurement sensitivity, it be suitable for testing capacitor capacity below 0.01 μ F to little electric capacity more than tens PF;

While using low capacity capacity measuring set, only need be by the two ends of red, black two test pencils while contact measured electric capacity, LED should be once glittering, then extinguishes, and shows that measured capacitance is intact; If LED is not glittering, represents the inner broken string of electric capacity or damage; If the glittering rear luminosity of LED is only dimmed, rather than extinguishes, represent the inner existence electric leakage of electric capacity; If LED Chang Liang does not extinguish, represent the short circuit of electric capacity inside;

When test low capacity electric capacity, staff two ends do not contact the metal part of red test pencil TX1, black meter pen TX2 simultaneously, otherwise have human body resistance to add, and can make LED send out all the time the low light level, easily think capacity fall off by mistake;

Low capacity capacity measuring set, can also be according to the luminous situation of LED, by the break-make situation of the circuit that conducts a survey except differentiating the quality of little capacitive property.

Claims

1. a low capacity capacity measuring set, it comprises 3V direct supply, same polarity Darlington circuit and display circuit, test interface, it is characterized in that:

Described same polarity Darlington circuit and display circuit are comprised of 3 NPN type triode VT1～VT3, the model that 3 NPN type triode VT1～VT3 select is 2SC9013, the emitter of NPN type triode VT1 connects the base stage of NPN type triode VT2, the emitter of NPN type triode VT2 connects the base stage of NPN type triode VT3, the emitter connection circuit ground GND of NPN type triode VT3, the anodal VCC of collector connection circuit of the collector of NPN type triode VT1 and NPN type triode VT2, the collector of NPN type triode VT3 connects the negative pole of LED, the anodal VCC of anodal connection circuit of LED,

Described test interface is exactly the anodal VCC of red test pencil TX1 connection circuit, and black meter pen TX2 connects the base stage of NPN type triode VT1 by resistance R 1;

The anodal VCC of described 3V DC power anode connection circuit, 3V DC power cathode connection circuit ground GND.