CN201194016Y - AC current detection circuit - Google Patents

AC current detection circuit Download PDF

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Publication number
CN201194016Y
CN201194016Y CNU2008200925731U CN200820092573U CN201194016Y CN 201194016 Y CN201194016 Y CN 201194016Y CN U2008200925731 U CNU2008200925731 U CN U2008200925731U CN 200820092573 U CN200820092573 U CN 200820092573U CN 201194016 Y CN201194016 Y CN 201194016Y
Authority
CN
China
Prior art keywords
resistance
mcu
port
alternating current
capacitance
Prior art date
Application number
CNU2008200925731U
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Chinese (zh)
Inventor
汪显方
杨勇练
邓宝宁
董晓勇
刘建伟
Original Assignee
深圳和而泰智能控制股份有限公司
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Priority to CNU2008200925731U priority Critical patent/CN201194016Y/en
Application granted granted Critical
Publication of CN201194016Y publication Critical patent/CN201194016Y/en

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Abstract

The utility model relates to an alternating current testing circuit, which comprises resistance R1, R2, R3 and a coupling capacitance C18. The resistance R1 is in series connection with a resistive load; the two ends of the resistance R2 are connected to a direct current reference voltage and the AD port of MCU respectively; the two ends of the resistance R3 are connected to the AD port of the MCU and earth; one end of the capacitance C18 is connected between the resistance R1 and the resistive load while the other end is connected to the AD port of the MCU. By adopting general electron devices, as resistance and capacitance, and the coupling action of capacitance, the utility model converts the alternating intense current signals in 220V in to low voltage signals, solves the problem of complex structure high cost in current testing circuits.

Description

A kind of testing circuit of alternating current

Technical field

The utility model relates to current detecting, more particularly, relates to a kind of testing circuit of alternating current.

Background technology

In current field, it generally is to adopt the electric current mutual inductor to induce the current signal of low pressure that present common detection 220V exchanges the forceful electric power signal, and this line cost is comparatively speaking than higher, and structure is also relatively complicated.As application number is 200620056273.9, name is called in the patent of " alternating current, the tension measuring circuit that adopt AC sampling ", disclose a kind of alternating current, tension measuring circuit that adopts AC sampling, this circuit comprises sample circuit, comparator circuit and single-chip microcomputer; Sample circuit is converted to the AC signal output to be checked that tool is determined proportionate relationship with the AC signal in loop to be checked; Comparator circuit is measured the frequency of described AC signal to be checked and this frequency signal is exported to and samples in the single-chip microcomputer; Be provided with the A/D change-over circuit in the single-chip microcomputer, the A/D change-over circuit carries out the A/D conversion to AC signal to be checked and exports the CPU of single-chip microcomputer to, CPU on the single-chip microcomputer is according to the frequency signal of comparator circuit input, and decision is calculated the size of AC signal and exported result of calculation the frequency of AC signal sampling.This current detection circuit complex structure, cost also compares higher.

The utility model content

The purpose of this utility model is to provide a kind of simple in structure, testing circuit of alternating current cheaply.

The technical scheme that its technical matters that solves the utility model adopts is: the testing circuit of constructing a kind of alternating current, comprise resistance R 1, R2, R3 and coupling capacitance C18, resistance R 1 is connected with resistive load, resistance R 2 two ends connect the AD port of DC reference voltage and MCU respectively, resistance R 3 two ends connect AD port and the ground of MCU respectively, one end of capacitor C 18 is connected between resistance R 1 and the resistive load, and the other end is connected to the AD port of MCU.

In the testing circuit of alternating current described in the utility model, described DC reference voltage is+5V ,+3V or+3.3V.

In the testing circuit of alternating current described in the utility model, described capacitor C 18 is a patch capacitor.

In the testing circuit of alternating current described in the utility model, described resistance R 1 is high-power little resistance sampling resistor, its resistance less than or Equal0.2 Ω.

The detection line of the alternating current that the utility model relates to adopts very general resistance capacitance electron device, coupling by electric capacity, the current signal of alternating current 220V forceful electric power is converted to the voltage signal of low pressure, can be used on electric power measuring instrument, the current detecting equipment.

Description of drawings

The utility model is described in further detail below in conjunction with drawings and Examples, in the accompanying drawing:

Fig. 1 is the schematic diagram of the testing circuit of the utility model alternating current;

Fig. 2 is a detected oscillogram from the AD port of MCU.

Embodiment

As shown in Figure 1, the testing circuit of alternating current of the present utility model comprises resistance R 1, R2, R3 and coupling capacitance C18, resistance R 1 is connected with resistive load, resistance R 2 two ends connect the AD port of DC reference voltage+5V and MCU respectively, resistance R 3 two ends connect AD port and the ground of MCU respectively, one end of capacitor C 18 is connected between sampling resistor R1 and the resistive load, and the other end is connected to the AD port of MCU.Load can be an incandescent lamp, also can be the load of heating wire constant resistance, and the utility model only is applicable to ohmic load, and is inapplicable for inductive and capacitive load.Wherein DC reference voltage+5V also can be other suitable MCU work voltage as+3V ,+3.3V etc., resistance R 1 is a sampling resistor, its resistance can not be too big, generally is not more than 0.2 Ω.Because the electric current that this resistance flows through is bigger, so generally adopt powerful resistance.Calculate according to resistive load, if the electric current of 1A, the power of resistance is exactly I*I*R=0.2W, if the electric current of 2A is exactly I*I*R=2*2*0.2=0.8W, so the power bracket of sampling resistor R1 generally is 0.2W-0.8W.Capacitor C 18 is 0805 common patch capacitors, and its capacitance is 0.1 μ preferably.The 220V alternating voltage is exactly the AC signal that is coupled out low pressure by C18, R2, R3 one termination+5V, and other end ground connection is provided to a reference voltage and detects to MCU.

Can detect waveform as shown in Figure 2 from the AD port of MCU, among the figure is with the alternating current of 50Hz for example, equally also may be used on the alternating current of 60Hz.AD port by MCU detects each magnitude of voltage in real time, and this magnitude of voltage is exactly the magnitude of voltage on the sampling resistor R1.By voltage U, electric current I, the formula I=U/R of resistance R just can calculate the instantaneous value of electric current.

The utility model has adopted very general resistance capacitance electron device just can play same effect, and price can be used on electric power measuring instrument, current detecting equipment less than adopting 1/10th of mutual inductor, and is also very competitive on market.The actual effect of this circuit is not worse than and adopts the circuit of stream device mutually, and is advantageous on the cost, and worth replacement mutual inductor circuit is also promoted.

Claims (5)

1. the testing circuit of an alternating current, it is characterized in that, comprise resistance R 1, R2, R3 and coupling capacitance C18, resistance R 1 is connected with resistive load, resistance R 2 two ends connect the AD port of DC reference voltage and MCU respectively, resistance R 3 two ends connect AD port and the ground of MCU respectively, and an end of capacitor C 18 is connected between resistance R 1 and the resistive load, and the other end is connected to the AD port of MCU.
2. the testing circuit of alternating current according to claim 1 is characterized in that, described DC reference voltage is+5V ,+3V or+3.3V.
3. the testing circuit of alternating current according to claim 1 is characterized in that, described capacitor C 18 is a patch capacitor.
4. the testing circuit of alternating current according to claim 1 is characterized in that, described resistance R 1 is high-power little resistance sampling resistor.
5. the testing circuit of alternating current according to claim 1 is characterized in that, the resistance of described resistance R 1 is less than or equal to 0.2 Ω.
CNU2008200925731U 2008-03-14 2008-03-14 AC current detection circuit CN201194016Y (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNU2008200925731U CN201194016Y (en) 2008-03-14 2008-03-14 AC current detection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNU2008200925731U CN201194016Y (en) 2008-03-14 2008-03-14 AC current detection circuit

Publications (1)

Publication Number Publication Date
CN201194016Y true CN201194016Y (en) 2009-02-11

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Family Applications (1)

Application Number Title Priority Date Filing Date
CNU2008200925731U CN201194016Y (en) 2008-03-14 2008-03-14 AC current detection circuit

Country Status (1)

Country Link
CN (1) CN201194016Y (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102243263A (en) * 2011-04-08 2011-11-16 苏州路之遥科技股份有限公司 Alternating current value detection and current zero crossing point detection circuit
CN102345878A (en) * 2010-08-03 2012-02-08 深圳市合信达控制系统有限公司 Flame ion current intensity detection and pulse ignition circuit
CN104237620A (en) * 2009-04-30 2014-12-24 日置电机株式会社 Voltage detection device

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104237620A (en) * 2009-04-30 2014-12-24 日置电机株式会社 Voltage detection device
CN104237620B (en) * 2009-04-30 2017-04-12 日置电机株式会社 voltage detection device
CN102345878A (en) * 2010-08-03 2012-02-08 深圳市合信达控制系统有限公司 Flame ion current intensity detection and pulse ignition circuit
CN102345878B (en) * 2010-08-03 2014-03-26 深圳市合信达控制系统有限公司 Flame ion current intensity detection and pulse ignition circuit
CN102243263A (en) * 2011-04-08 2011-11-16 苏州路之遥科技股份有限公司 Alternating current value detection and current zero crossing point detection circuit

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Date Code Title Description
GR01 Patent grant
C14 Grant of patent or utility model
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20090211

Termination date: 20170314

CF01 Termination of patent right due to non-payment of annual fee