CN103439618A

CN103439618A - Low-capacity capacitor tester

Info

Publication number: CN103439618A
Application number: CN2013104053855A
Authority: CN
Inventors: 黄月华
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-09-09
Filing date: 2013-09-09
Publication date: 2013-12-11

Abstract

The invention provides a low-capacity capacitor tester. The low-capacity capacitor tester is characterized by comprising a 3 V DC power supply, a same-polarity Darlington circuit and display circuit, and a test interface, wherein the three NPN-type triodes VT1-VT3 of the same-polarity Darlington circuit and display circuit are 2SC9013 triodes. It is difficult to test a capacitor with a capacity of below 0.01 [mu] F by a conventional universal meter. Though there are many methods to test a low-capacity capacitor, the most convenient method involves using a digital capacitance meter for testing for the best. However, it is not easy for ordinary electronic workers or amateur electronics lovers to equip themselves with a professional capacitor tester. For the purpose of solving the general measuring requirements of the low-capacity capacitor, the same-polarity Darlington triodes are adopted in the circuit of the low-capacity capacitor tester provided by the invention, so that the requirements of a device for driving power can be substantially recued, and the general performance of the small-capacity capacitor is determined by whether a light emitting diode emits light or not.

Description

The low capacity capacity measuring set

Technical field

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

Background technology

Be difficult to the electric capacity of test capacity below 0.01 μ F with common multimeter, although test low capacity electric capacity has several different methods, but, should use the most easily the digital capacitance meter test, but professional capacitance measuring instrument all is 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 of the present invention is used the 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 of the present invention related relevant technologies content in implementation process in detail.

Summary of the invention

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 the digital capacitance meter test, but professional capacitance measuring instrument all is 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 of the present invention is used the 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.

The 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, the one charging current testing capacitance of flowing through is just arranged, although this charging current is very small, through the Darlington triode VT1 of high-amplification-factor～VT3, amplify metapedes to drive LED to be lit.If LED is not luminous, mean that electric capacity is without charging ability, the inner broken string of measured capacitance is described or damages.

Technical characterictic: the 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 the collector connection circuit of the collector of NPN type triode VT1 and NPN type triode VT2, the negative pole of the collector sending and receiving optical diode LED of NPN type triode VT3, the anodal VCC of the 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 the anodal connection circuit of 3V direct supply, the negative pole connection circuit ground GND of 3V direct supply.

The accompanying drawing explanation

Accompanying drawing is the embodiment circuit working schematic diagram that the invention 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 described each several part circuit of summary of the invention, and the components and parts technical parameter described in embodiment requires and the circuit production main points are implemented to realize the present invention, below in conjunction with embodiment, correlation technique of the present invention is further described.

Components and parts are selected and technical parameter

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

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;

The 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

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

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

While using the low capacity capacity measuring set, only need 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, means the inner broken string of electric capacity or damage; If the glittering rear luminosity of LED is only dimmed, rather than extinguishes, mean the inner existence electric leakage of electric capacity; If LED Chang Liang does not extinguish, mean the short circuit of electric capacity inside;

When test low capacity electric capacity, the 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;

The 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 the quality that can differentiate 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 the collector connection circuit of the collector of NPN type triode VT1 and NPN type triode VT2, the negative pole of the collector sending and receiving optical diode LED of NPN type triode VT3, the anodal VCC of the 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.