CN218524791U

CN218524791U - Ammeter zero-crossing detection circuit

Info

Publication number: CN218524791U
Application number: CN202221715494.8U
Authority: CN
Inventors: 徐千朗悦; 黄宏章; 张俊
Original assignee: Junkaidi Technology Shenzhen Co ltd
Current assignee: Junkaidi Technology Shenzhen Co ltd
Priority date: 2022-07-05
Filing date: 2022-07-05
Publication date: 2023-02-24
Anticipated expiration: 2032-07-05

Abstract

The utility model discloses an ammeter zero passage detection circuit, including phase line A and zero line N, detection circuitry is connected to phase line A and zero line N. The utility model discloses an ammeter ZERO cross detection circuit, when the incoming phase voltage is very little, when the alternating current is close 0V promptly, optical coupler OP1 and triode Q1 can't switch on because of voltage is too little, cause output ZERO signal to become the high level by the low level, be ZERO cross signal this moment, when the alternating current is in the burden half cycle, can not pass through diode D1, can not form voltage at triode Q1's base and be higher than 0.7V, consequently triode Q1 and optical coupler OP1 do not switch on, ZERO cross ZERO signal line output VCC voltage amplitude, border between the positive half cycle and the burden half cycle when detecting the alternating current, be the place for ZERO volt for exchanging promptly, provide accurate ZERO cross signal, be applicable to the product that needs alternating current ZERO cross signal, ZERO cross signal is very close actually, the degree of accuracy has been improved greatly.

Description

Ammeter zero-crossing detection circuit

Technical Field

The utility model relates to an ammeter zero passage detection technical field specifically is an ammeter zero passage detection circuit.

Background

The existing zero-crossing detection circuit mostly obtains a zero-crossing point in a mode of resistor voltage division or voltage regulator tubes, although the method is easy to implement and low in cost, the method is poor in aspects of electrical isolation, anti-interference capability and the like, meanwhile, fewer devices are used for products of alternating current zero-crossing signals, and data of zero-crossing detection is inaccurate due to positive half cycles and negative half cycles of alternating current.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an ammeter zero passage detection circuit has for exchanging the place for zero volt, provides accurate zero passage signal, is applicable to the product that needs alternating current zero passage signal, and zero passage signal is very close actually, has improved the advantage of the degree of accuracy greatly, has solved the problem among the prior art.

In order to achieve the above purpose, the utility model provides a following technical scheme: a zero-crossing detection circuit of an ammeter comprises a phase line A and a zero line N, wherein the phase line A and the zero line N are connected with the detection circuit.

Preferably, the anode of the diode D1 in the detection circuit is connected to the phase line a, the cathode of the diode D1 is connected in series to the resistor R1 and the resistor R2, and the other end of the resistor R2 is connected in parallel to the capacitor C2, the resistor R3, the capacitor C1 and the zener diode ZD1 on the optocoupler OP 1;

the optical coupler OP1 is also connected with the collector of the triode Q1, the base of the triode Q1 is connected with the parallel connection port of the resistor R5 and the capacitor C4, the other end of the resistor R5 is connected with the negative electrodes of the resistor R3, the capacitor C2 and the diode D2 in parallel on the zero line N, and the positive electrode of the diode D2 is connected with the other ends of the capacitor C1, the voltage stabilizing diode ZD1 and the capacitor C4 in parallel on the emitter of the triode Q1;

and the other two end corners of the optical coupler OP1 are connected with a resistor R4 and a capacitor C3 which are grounded in parallel on a ZERO signal wire.

Preferably, alternating current is introduced to the phase line a, and the alternating current drives the optocoupler OP1 and the triode Q1 to be turned on or off.

Preferably, the zener diode ZD1 is used in the optocoupler OP1 to avoid burning out due to too high voltage.

Compared with the prior art, the beneficial effects of the utility model are as follows:

the utility model discloses an ammeter zero passage detection circuit, when the juncture that detects the positive half cycle and the negative half cycle of alternating current, exchange for the place of zero volts promptly, provide accurate zero cross signal, be applicable to the product that needs alternating current zero cross signal, zero cross signal is very close actually, has improved the degree of accuracy greatly.

Drawings

Fig. 1 is an overall structure diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In order to solve the problem that in the prior art, most of the existing zero-crossing detection circuits use a resistor voltage-dividing or voltage-stabilizing tube to obtain a zero-crossing point, although the method is easy to implement and has low cost, the method is poor in aspects of electrical isolation, anti-interference capability and the like, and meanwhile, few devices are used for products of alternating current zero-crossing signals, and data of zero-crossing detection is inaccurate due to positive half cycles and negative half cycles of alternating current, please refer to fig. 1, and the following technology is provided:

an ammeter zero-crossing detection circuit comprises a phase line A and a zero line N, wherein the phase line A and the zero line N are connected with the detection circuit. The anode of a diode D1 in the detection circuit is connected with a phase line A, the cathode of the diode D1 is connected with a resistor R1 and a resistor R2 in series, and the other end of the resistor R2 is connected with a capacitor C2, a resistor R3, a capacitor C1 and a voltage stabilizing diode ZD1 in parallel on an optical coupler OP 1;

the optical coupler OP1 is also connected with the collector of the triode Q1, the base of the triode Q1 is connected with the parallel connection port of the resistor R5 and the capacitor C4, the other end of the resistor R5 is connected with the resistor R3, the capacitor C2 and the cathode of the diode D2 in parallel on the zero line N, and the anode of the diode D2 is connected with the other ends of the capacitor C1, the voltage stabilizing diode ZD1 and the capacitor C4 in parallel on the emitter of the triode Q1;

the remaining two corners of the optocoupler OP1 are connected to VCC voltage, and the other corner is connected to ZERO signal line in parallel with the resistor R4 and the capacitor C3 connected to ground.

Alternating current is introduced to the phase line A, and the alternating current drives the optocoupler OP1 and the triode Q1 to be switched on or switched off.

Specifically, when the positive half cycle of alternating current can pass through a diode D1, pass through resistors R1 and R2, and a voltage stabilizing tube ZD1 stabilizes voltage, at this time, an optical coupler OP1 is conducted and a triode Q1 is conducted, and 0V is output on a ZERO-crossing ZERO signal line;

when the input phase voltage is very small, namely the alternating current is close to 0V, the optical coupler OP1 and the triode Q1 cannot be conducted due to too small voltage, so that the output ZERO signal is changed from low level to high level, namely the ZERO-crossing signal, and the rear end can operate required actions according to the ZERO-crossing signal.

When the alternating current is in a negative half cycle, the alternating current cannot pass through the diode D1, and the voltage higher than 0.7V cannot be formed at the base electrode of the triode Q1, so that the triode Q1 and the optical coupler OP1 are not conducted, the ZERO-crossing ZERO signal line outputs a VCC voltage amplitude, the ZD1 is a voltage stabilizing diode, and the optical coupler OP1 is protected from being burnt due to overhigh voltage.

The function and the effect are as follows: the junction of the positive half cycle and the negative half cycle of the alternating current is detected, namely the junction of the alternating current is zero voltage, an accurate zero-crossing signal is provided, the method is suitable for products needing the alternating current zero-crossing signal, the zero-crossing signal is very close to reality, and the accuracy is greatly improved.

In summary, the following steps: the utility model discloses an ammeter ZERO cross detection circuit, when the positive half cycle of alternating current can pass through diode D1, through resistance R1 and R2, stabilivolt ZD1 steady voltage, and optical coupler OP1 switches on and triode Q1 switches on at this moment, outputs 0V on the ZERO cross ZERO signal line; when the input phase voltage is very small, namely the alternating current is close to 0V, the optical coupler OP1 and the triode Q1 cannot be conducted due to too small voltage, so that the output ZERO signal is changed from low level to high level, namely the ZERO-crossing signal, and the rear end can operate required actions according to the ZERO-crossing signal. When the alternating current is in a negative half cycle, the alternating current cannot pass through the diode D1, and the voltage higher than 0.7V cannot be formed at the base electrode of the triode Q1, so that the triode Q1 and the optical coupler OP1 are not conducted, the ZERO-crossing ZERO signal line outputs a VCC voltage amplitude, the ZD1 is a voltage stabilizing diode, and the optical coupler OP1 is protected from being burnt due to overhigh voltage.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides an ammeter zero cross detection circuit, includes phase line A and zero line N, its characterized in that: the phase line A and the zero line N are connected with a detection circuit;

the anode of a diode D1 in the detection circuit is connected with a phase line A, the cathode of the diode D1 is connected with a resistor R1 and a resistor R2 in series, and the other end of the resistor R2 is connected with a capacitor C2, a resistor R3, a capacitor C1 and a voltage stabilizing diode ZD1 in parallel on an optical coupler OP 1;

the optical coupler OP1 is also connected with a collector of the triode Q1, a base of the triode Q1 is connected with a parallel connection port of a resistor R5 and a capacitor C4, the other end of the resistor R5 is connected with a resistor R3, a capacitor C2 and a cathode of a diode D2 in parallel and connected to a zero line N, and an anode of the diode D2 is connected with the other ends of the capacitor C1, a voltage stabilizing diode ZD1 and the capacitor C4 in parallel and connected to an emitter of the triode Q1;

2. An electricity meter zero-crossing detection circuit as claimed in claim 1, wherein an alternating current is applied to the phase line a, and the alternating current drives the optocoupler OP1 and the transistor Q1 to be turned on or off.

3. A zero-crossing detection circuit for an electricity meter according to claim 1, wherein the zener diode ZD1 is used for the optocoupler OP1 to avoid burning out due to over-voltage.