CN2159026Y - Liquid crystal numerical AC current meter - Google Patents
Liquid crystal numerical AC current meter Download PDFInfo
- Publication number
- CN2159026Y CN2159026Y CN 93203704 CN93203704U CN2159026Y CN 2159026 Y CN2159026 Y CN 2159026Y CN 93203704 CN93203704 CN 93203704 CN 93203704 U CN93203704 U CN 93203704U CN 2159026 Y CN2159026 Y CN 2159026Y
- Authority
- CN
- China
- Prior art keywords
- liquid crystal
- amplifier
- current
- utility
- power supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Abstract
The utility model relates to a liquid crystal digital AC current meter, which is a device used for displaying current in a digital form. The utility model is used for an apparatus or a device used for measuring various power frequencies of AC current. The utility model comprises a DC current power supply, a detecting loop, an amplifier, an A/D convertor and a liquid crystal digital display, wherein, the DC current power supply is composed of a power supply, a coupling capacitor, a rectifier and a voltage stabilizer, the detecting loop is composed of an induction coil and an amplifier, and the measured induction signal of the induction coil is transmitted to the liquid crystal digital display through the amplification, the demodulation and the A/D conversion. The utility model has the advantages that the current transformer of the existing meter is replaced with the induction coil of which the weight is only a plurality of grams, and the amplifier, the power transformer is replaced with the coupling capacitor, the size, the weight and the cost are reduced largely, and the precision and the measuring range are increased.
Description
The utility model relates to a kind of device that shows electric current with digital form.
Existing alternating current ammeter, there are pointer-type, pointer to add shunt formula or D.C mutual-inductor formula (being used to measure big electric current), if it is digital, except that need use AC current transformer as detecting the loop, the direct supply of this instrument or the direct supply of being changed by power transformer also will be provided, and its volume and weight is all bigger.
The purpose of this utility model is to provide a kind of instrument that is mainly used in the various industrial frequency AC electric currents of measurement of liquid crystal digital demonstration or the liquid crystal digital alternating current ammeter on the device.
The utility model comprises direct supply, detects loop, amplifier, wave detector, A/D converter and liquid crystal digital display.Direct supply is made up of communication power supply and coupling capacitance, rectifier, pressure stabilization filter, supply with the required direct supply of instrument, detecting the loop adopts telefault to add amplifier, the brilliant digital indicator of the tested induced signal of telefault liquor charging behind amplifier, wave detector and A/D converter is to show tested current value.
Above-mentioned telefault matches with amplifier and has replaced the D.C mutual-inductor of usually nearly 1Kg.
The DC power voltage stabilizing device adopts the two-stage diode circuit of voltage regulation.
The utility model utilization only has the telefault (have not iron core all can) of several grams to add operational amplifier and has replaced current transformer in the existing instrument, the volume and weight of instrument is compared with existing instrument of the same type all be about 1/100.Next has adopted capacitive coupling to replace the direct current supply of transformer to circuit, and the volume of power unit and weight are dwindled significantly.Respectively 18V and 9V are carried out voltage stabilizing by the two-stage voltage stabilizing diode in addition, satisfied the requirement of A/D converter to high stability dc power supply, guaranteed the precision of instrument, its error is less than ± 1.2%, and measurement range can be from 100MA to 20000A.In addition, also can utilize the power supply before the voltage stabilizing that illumination is provided, not only solve illumination but also guaranteed the safety of circuit, instrument not had under the light at night also can observe.
Fig. 1 is a functional-block diagram of the present utility model.
Fig. 2 is circuit theory diagrams of the present utility model.
Embodiment:
As depicted in figs. 1 and 2, the utility model comprises direct supply (2), telefault (3), amplifier (4), wave detector (5), A/D converter (6) and liquid crystal digital display (7).
Communication power supply (1) is through coupling capacitance C
5To bridge rectifier and C
8, D
8, C
9, D
9The two-stage voltage stabilizing is with the direct-current power supply instrument each several part circuit of 9V.
Behind instrument incoming transport power supply, as telefault L
1When receiving the signal of circuit-under-test, its signal is through C
2Provide the LM358-1 operational amplifier to amplify, the calibrated potentiometer W of the signal after the amplification
1, its part is through C
6Provide LM358-2 to amplify once more, the calibrated resistance R of the signal after the amplification
14And R
15, a part wherein is through C
13And C
14, D
2, D
3Providing LM358-3 to carry out phase place amplifies.The phase place amplifying signal is through C
18And by D
7Carry out detection, then through R
23, R
24, C
17Filtering, voltage stabilizing, and 31 pin of importing 7106 assemblies carry out the A/D conversion, the brilliant digital indicator of last liquor charging shows tested current value.
D among the figure
1, C
7, R
1～R
4, R
7～R
11As the voltage stabilizing element of LM operational amplifier, R
5, C
4, R
12, C
10, R
22, C
17Be respectively the negative feedback component of each operational amplifier.
Telefault does not preferably have the air core coil of iron core.
Claims (3)
1, a kind of liquid crystal digital alternating current ammeter comprises direct supply, detects loop, amplifier, A/D converter and liquid crystal digital display, it is characterized in that
(1) direct supply is made up of communication power supply and coupling capacitance, rectifier, pressure stabilization filter;
(2) detect the loop and adopt telefault to add amplifier, the brilliant digital indicator of the tested induced signal of telefault liquor charging behind amplifier, wave detector and A/D converter.
2, reometer as claimed in claim 1 is characterized in that the DC power voltage stabilizing device adopts the two-stage diode circuit of voltage regulation.
3, reometer as claimed in claim 1 is characterized in that adopting air-core inductance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 93203704 CN2159026Y (en) | 1993-02-16 | 1993-02-16 | Liquid crystal numerical AC current meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 93203704 CN2159026Y (en) | 1993-02-16 | 1993-02-16 | Liquid crystal numerical AC current meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2159026Y true CN2159026Y (en) | 1994-03-16 |
Family
ID=33787488
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 93203704 Expired - Fee Related CN2159026Y (en) | 1993-02-16 | 1993-02-16 | Liquid crystal numerical AC current meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2159026Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100416278C (en) * | 2001-06-20 | 2008-09-03 | 陈丽黄 | Novel digital/analog double display AC electric meter |
-
1993
- 1993-02-16 CN CN 93203704 patent/CN2159026Y/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100416278C (en) * | 2001-06-20 | 2008-09-03 | 陈丽黄 | Novel digital/analog double display AC electric meter |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |