CN202421385U

CN202421385U - Portable transformer tester

Info

Publication number: CN202421385U
Application number: CN2012200176039U
Authority: CN
Inventors: 叶财; 杨雷; 陈方舟
Original assignee: Dongguan University of Technology
Current assignee: Dongguan University of Technology
Priority date: 2012-01-16
Filing date: 2012-01-16
Publication date: 2012-09-05
Anticipated expiration: 2022-01-16

Abstract

The utility model provides a portable transformer tester, comprising a main controller, a primary coil and secondary coil judging circuit bi-directionally connected with the main controller, a transformer primary coil measuring circuit and a transformer secondary coil measuring circuit, a temperature sensor connected with an input end of the main controller, and a liquid crystal display connected with an output end of the main controller. The main controller of the tester is a singlechip, the primary coil and secondary coil judging circuit consists of a program-controlled constant-current source and a measuring transformer direct current resistance circuit which are sequentially connected, and the program-controlled constant-current source consists of a DA (digital-to-analogue) conversion circuit and an operating and amplifying circuit. The transformer primary coil measuring circuit consists of a DDS (direct digital synthesis) signal generator, a broadband amplifying circuit, a transformer primary coil, a base difference amplifying circuit and an effective value conversion circuit which are sequentially connected, and the transformer secondary coil measuring circuit consists of a transformer secondary coil, a base difference amplifying circuit, a gain-adjustable amplifying circuit, a signal processing circuit and an effective value conversion circuit which are sequentially connected.

Description

A kind of portable transformer tester

Technical field

The utility model relates to a kind of instrument that is used for transformer testing, particularly relates to a kind of portable transformer tester.

Background technology

Traditional transformer testing instrument is with the no-load voltage ratio of no-load voltage ratio bridge measurement transformer; Operating process is loaded down with trivial details, and measurement range is narrow, and is difficult for handling the not clear voltage device of primary and secondary; Instrument involves great expense simultaneously; Bulky, the utmost point is not portable, the fast pace of incompatibility modern surveying, intellectuality, high efficiency requirement.

The utility model content

The purpose of the utility model is to overcome the deficiency of prior art, and a kind of portable transformer tester is provided, and volume is less, is easy to carry about with one, and is simple in structure, and cost is low, and has guaranteed measurement accuracy and degree of accuracy.

In order to achieve the above object; The technical scheme that the utility model adopts is: a kind of portable transformer tester; Comprise master controller; Described tester also comprises and the two-way primary winding that links to each other of master controller and secondary coil decision circuitry, primary of transformer metering circuit and transformer secondary coil metering circuit, the temperature sensor that is connected with the input end of master controller, the LCD that is connected with the output terminal of master controller.Primary winding and secondary coil decision circuitry are judged the primary winding and the secondary coil of transformer judge which part and be primary winding, where are secondary coil partly, after the judgement, measure to primary winding and secondary coil respectively.

Further, the master controller of described tester is a single-chip microcomputer.

Further, primary winding of described tester and secondary coil decision circuitry are by interconnective program controlled constant current source, measuring transformer direct current resistance circuit are formed successively.

Further, described program controlled constant current source is made up of DA D/A converting circuit and discharge circuit.

Further; The primary of transformer metering circuit of described tester is by interconnective DDS signal generating circuit, wideband amplification circuit, primary of transformer, basic differential amplifier circuit and effective value change-over circuit are formed successively; The input end of DDS signal generating circuit is connected with master controller, and the output terminal of effective value change-over circuit is connected with the input end of master controller.

Further, the transformer secondary coil metering circuit of described tester is by interconnective transformer secondary coil, basic differential amplifier circuit, Gain Adjustable amplifying circuit, signal processing circuit, effective value change-over circuit are formed successively.

Compared with prior art, the beneficial effect of the utility model is: volume is less, is easy to carry about with one, and is simple in structure, and cost is low, and guaranteed measurement accuracy and degree of accuracy.

Description of drawings

Fig. 1 is the schematic block circuit diagram of the utility model;

Fig. 2 is the specific embodiment synoptic diagram of Fig. 1.

Embodiment

Be elaborated with reference to accompanying drawing below in conjunction with embodiment, so that the technical characterictic and the advantage of the utility model are carried out more deep annotation.

The schematic block circuit diagram of the utility model is like Fig. 1, shown in 2; A kind of portable transformer tester; Comprise master controller; Described tester also comprises and the two-way primary winding that links to each other of master controller and secondary coil decision circuitry, primary of transformer metering circuit and transformer secondary coil metering circuit, the temperature sensor that is connected with the input end of master controller, the LCD that is connected with the output terminal of master controller.

This product is master controller with the single-chip microcomputer, through the constant-current source circuit that control DA and amplifier are constituted, realizes the controllability of output current; It is inserted the two ends of transformer; Just can measure direct current resistance, the primary and secondary that is used for transformer judges that using relay after is elementary with the big end of direct current resistance to four pins of transformer; The other end is secondary, the transposing good position.The programmable waveform generator that with the precision is 0.1Hz reference frequency output 0MHz-12.5MHz is a signal generator; Through sealing in sampling resistor after the processing and amplifying; Insert transformer and effective value change-over circuit; Simultaneously incorporate differential amplifier circuit into, so just can extract the current/voltage of input at the two ends of primary winding.Secondary coil connects basic differential amplifier circuit; Can be anti-interference, common-mode signal is suppressed, difference mode signal is amplified; Because the output voltage of secondary coil is little; So through by the controllable gain amplifying circuit that DAC0832 constituted it being carried out controlled amplification, the effective value change-over circuit through being built by AD637 after amplifying---allow the crest factor measurement signal to be up to 10, extra error is less than 1%.Wide bandwidth allows to measure 200mV root mean square, frequency is up to the input signal of 600kHz and the input signal that 1V root mean square is above, frequency is up to 8MHz, because AD637 is output as simulating signal, can converts digital signal to through AD and send into to CPU.CPU measures Current Temperatures through the DS18B20 temperature sensor, and the characterisitic parameter of respectively organizing that will handle simultaneously inserts 12864 liquid crystal together with temperature with serial, and shows.

The content of mentioning in the foregoing description is not to be the qualification to the utility model, and under the prerequisite of the utility model design that does not break away from the utility model, and any conspicuous replacement is all within the protection domain of the utility model.

Claims

1. portable transformer tester; Comprise master controller; It is characterized in that: described tester also comprises and the two-way primary winding that links to each other of master controller and secondary coil decision circuitry, primary of transformer metering circuit and transformer secondary coil metering circuit; The temperature sensor that is connected with the input end of master controller, the LCD that is connected with the output terminal of master controller.

2. portable transformer tester according to claim 1 is characterized in that: the master controller of described tester is a single-chip microcomputer.

3. portable transformer tester according to claim 2 is characterized in that: primary winding of described tester and secondary coil decision circuitry are by interconnective program controlled constant current source, measuring transformer direct current resistance circuit are formed successively.

4. portable transformer tester according to claim 3 is characterized in that: described program controlled constant current source is made up of DA D/A converting circuit and discharge circuit.

5. portable transformer tester according to claim 3; It is characterized in that: the primary of transformer metering circuit of described tester is by interconnective DDS signal generating circuit, wideband amplification circuit, primary of transformer, basic differential amplifier circuit and effective value change-over circuit are formed successively; The input end of DDS signal generating circuit is connected with master controller, and the output terminal of effective value change-over circuit is connected with the input end of master controller.

6. portable transformer tester according to claim 5 is characterized in that: the transformer secondary coil metering circuit of described tester is by interconnective transformer secondary coil, basic differential amplifier circuit, Gain Adjustable amplifying circuit, signal processing circuit, effective value change-over circuit are formed successively.