CN215641463U

CN215641463U - Common cathode signal conversion circuit for cost control circuit breaker

Info

Publication number: CN215641463U
Application number: CN202120605413.8U
Authority: CN
Inventors: 谈赛; 龙友贤; 程建; 贾俊; 戴旭毅; 苏西蒙
Original assignee: Wasion Electric Co Ltd
Current assignee: Weisheng Energy Technology Co ltd
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2022-01-25
Anticipated expiration: 2031-03-25

Abstract

The utility model relates to a common cathode signal conversion circuit for a cost-controlled circuit breaker, which is composed of an optocoupler U1, an NMOS tube V1, an NMOS tube V2, a diode D1, a diode D2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1 and a capacitor C2. The circuit overcomes the problem that a conventional fee control signal conversion circuit needs an independent power supply, is driven only by depending on a signal output by a fee control signal on the basis of not needing an external independent power supply, can realize connection with a circuit breaker of a common cathode remote control input contact, realizes a fee control function, and has the characteristics of extremely low power consumption, low cost, simple circuit and reliable operation.

Description

Common cathode signal conversion circuit for cost control circuit breaker

Technical Field

The utility model relates to the field of signal conversion circuits, in particular to a common cathode signal conversion circuit for a charge control circuit breaker.

Background

The existing fee control electric energy meter has the charge control signal of an alternating current signal, when the electric energy meter is in a fee state, a fee control output contact inside the electric energy meter is closed, and at the moment, the output voltage is the fee control signal of AC 220V. When the electric energy meter is in an arrearage state, the fee control output contact in the electric energy meter is disconnected, and the output voltage is 0 at the moment. And the corresponding cost control special circuit breaker determines whether the circuit breaker is in a closing state or an opening state by receiving the cost control signal.

However, for the non-cost-control-based special circuit breaker, since the signal access point for controlling opening and closing is an active contact, the voltage of the active contact is generally direct current low voltage, and the active contact cannot be compatible with the output voltage of the cost-control contact of the existing cost-control electric energy meter, the conversion needs to be performed through a cost-control signal conversion circuit. The conventional charge control signal conversion circuit performs conversion through an active level conversion circuit, but the circuit needs an independent power supply, is complex, high in cost and high in power consumption, and is not suitable for charge control conversion occasions.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention provides a common cathode signal conversion circuit for a cost-controlled circuit breaker, including an optocoupler U1, an NMOS transistor V1, an NMOS transistor V2, a diode D1, a diode D2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a resistor R5.

The anode of the optical coupler U1 is connected with an electric energy meter cost control signal output contact FK _ L through the resistor R2, the cathode of the optical coupler U1 is connected with an electric energy meter cost control signal output contact FK _ N, the grid of the NMOS tube V1 is connected with the emitter of the optical coupler U1, the source of the NMOS tube V1 is connected with a common cathode power supply contact COM-of a circuit breaker, the resistor R4 is connected between the grid and the source of the NMOS tube V1, the drain of the NMOS tube V1 is connected with the anode of the diode D1, the anode of the diode D1 is connected with a control closing input contact HZ +, the cathode of the diode D1 is connected with the collector of the optical coupler U1 through the resistor R1, the grid of the NMOS tube V2 is connected with the anode of the diode D1 through the resistor R3, and the source of the NMOS tube V2 is connected with a common cathode power supply contact COM-of the circuit breaker, the resistor R5 is connected between the grid and the source of the NMOS tube V2, the drain of the NMOS tube V2 is connected with the anode of the diode D2, the anode of the diode D2 is connected with a breaker control opening input contact FZ +, and the cathode of the diode D2 is connected with the collector of the optocoupler U1 through the resistor R1.

Preferably, the common cathode signal conversion circuit for the fiscal circuit breaker further comprises a capacitor C1, and the capacitor C1 is connected between the gate and the source of the NMOS transistor V1.

Preferably, the common cathode signal conversion circuit for the fiscal circuit breaker further comprises a capacitor C2, and the capacitor C2 is connected between the gate and the source of the NMOS transistor V2.

Preferably, the current transmission ratio of the optical coupler U1 is 300-600%.

Preferably, the resistor R1, the resistor R2, the resistor R3, the resistor R4 and the resistor R5 are in the megaohm range.

The circuit overcomes the problem that a conventional fee control signal conversion circuit needs an independent power supply, is driven only by depending on a signal output by a fee control signal on the basis of not needing an external independent power supply, can realize connection with a circuit breaker of a common cathode remote control input contact, realizes a fee control function, and has the characteristics of extremely low power consumption, low cost, simple circuit and reliable operation.

Drawings

FIG. 1 is a diagram of a common cathode signal conversion circuit for a cost-controlled circuit breaker.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

As shown in fig. 1, the common cathode signal conversion circuit for the cost-controlled circuit breaker comprises an optocoupler U1, an NMOS transistor V1, an NMOS transistor V2, a diode D1, a diode D2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1 and a capacitor C2. The anode of the optical coupler U1 is connected with an electric energy meter cost control signal output contact FK _ L through the resistor R2, the cathode of the optical coupler U1 is connected with an electric energy meter cost control signal output contact FK _ N, the grid of the NMOS tube V1 is connected with the emitter of the optical coupler U1, the source of the NMOS tube V1 is connected with a breaker common cathode power supply contact COM-, the resistor R4 and the capacitor C1 are connected in parallel between the grid and the source of the NMOS tube V1, the drain of the NMOS tube V1 is connected with the anode of the diode D1, the anode of the diode D1 is connected with a breaker control closing input contact HZ +, the cathode of the diode D1 is connected with the collector of the optical coupler U1 through the resistor R1, the grid of the NMOS tube V2 is connected with the anode of the diode D1 through the resistor R3, and the source of the NMOS tube V2 is connected with the common cathode power supply contact COM-, the resistor R5 and the capacitor C2 are connected in parallel between the grid and the source of the NMOS transistor V2, the drain of the NMOS transistor V2 is connected with the anode of the diode D2, the anode of the diode D2 is connected with a breaker control opening input contact FZ +, and the cathode of the diode D2 is connected with the collector of the optocoupler U1 through the resistor R1.

When the cost control signal output contacts FK _ L and FK _ N of the electric energy meter have no voltage, the resistor R2 and the input loop of the optocoupler U1 are not conducted, so that the optocoupler U1 has no output, namely the optocoupler output is switched off. When the optical coupler U1 has no output, the voltage of the grid electrode of the NMOS tube V1 is pulled down by the resistor R4 to be consistent with the common cathode power supply contact COM-of the circuit breaker. Therefore, the voltage difference between the grid electrode and the source electrode of the NMOS tube V1 is 0, the opening threshold value of the NMOS tube V1 cannot be reached, the NMOS tube V1 is turned off, and the breaker cannot be switched on.

At the same time, since the NMOS transistor V1 is turned off and the breaker control closing input contact HZ + signal is high, a signal path of R3 and R5 is formed, and a voltage difference is provided across R5. Therefore, the grid electrode and the source electrode of the NMOS tube V2 have voltage difference, when the voltage difference is larger than the opening threshold value of the NMOS tube V2, the NMOS tube V2 is conducted, the circuit breaker controls the opening input contact FZ + and the common cathode power supply contact COM-of the circuit breaker to form a loop, and the circuit breaker is opened. Therefore, the opening and closing of the circuit breaker form an interlocking relationship.

When the cost control signal output contacts FK _ L and FK _ N of the electric energy meter have voltage, the resistor R1 is conducted with the input loop of the optocoupler U1, so that the output of the optocoupler U1 is conducted. When the optical coupler U1 is switched on, an electric loop is formed by the D2, the R1, the U1 and the R4. The voltage difference between the grid electrode and the source electrode of the NMOS tube V1 is larger than the opening threshold value of the NMOS tube V1, so that the NMOS tube V1 is conducted, the circuit breaker controls a closing input contact HZ + signal and a common cathode power supply contact COM-signal of the circuit breaker to form a loop, and the circuit breaker is closed.

Meanwhile, because the voltage of the corresponding R3 and R5 loops is 0, the voltage of the grid electrode and the source electrode of the NMOS tube V2 is also 0 and is smaller than the opening threshold value of the switching tube, the NMOS tube V2 is turned off, and the breaker cannot be opened.

Because the charge control signal of the electric energy meter is an alternating current signal and the signal changes according to the period, in order to ensure the stable level of the control signals of the NMOS transistor V1 and the NMOS transistor V2, capacitors are connected in parallel between the source electrode and the grid electrode of the NMOS transistor V1 and the NMOS transistor V2 for filtering, so that the control signals are stable.

Because the electric energy meter cost control signal current is minimum, generally is less than 200uA, and the drive optocoupler capacity is extremely weak, the output drive capacity of the optocoupler is weak, so that the circuit can work under the extremely low power consumption. The current transmission ratio of the optical coupler should be large, preferably 300% to 600%. The resistance of the resistor should be large, preferably in the order of mega ohms.

The embodiment of the utility model can carry out sequence adjustment, combination and deletion according to actual needs.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and those modifications and variations assumed in the above are also considered to be within the protective scope of the present invention.

Claims

1. A common cathode signal conversion circuit for a cost-controlled circuit breaker, comprising:

the device comprises an optical coupler (U1), an NMOS tube V1, an NMOS tube V2, a diode D1, a diode D2, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor R5;

the anode of the optical coupler (U1) is connected with an electric energy meter cost control signal output contact FK _ L through the resistor R2, the cathode of the optical coupler (U1) is connected with an electric energy meter cost control signal output contact FK _ N, the grid of the NMOS tube V1 is connected with the emitter of the optical coupler (U1), the source of the NMOS tube V1 is connected with a breaker common cathode power supply contact (COM-), the resistor R4 is connected between the grid and the source of the NMOS tube V1, the drain of the NMOS tube V1 is connected with the anode of the diode D1, the anode of the diode D1 is connected with a breaker control closing input contact (HZ +), the cathode of the diode D1 is connected with the collector of the optical coupler (U1) through the resistor R1, the grid of the NMOS tube V2 is connected with the anode of the diode D1 through the resistor R3, and the source of the NMOS tube V2 is connected with a breaker common cathode power supply contact (COM-), the resistance R5 is connected between the grid of NMOS pipe V2 and the source electrode, the drain electrode of NMOS pipe V2 with diode D2's positive pole is connected, diode D2's positive pole and circuit breaker control separating brake input contact (FZ +) are connected, diode D2's negative pole is passed through resistance R1 with the collecting electrode of opto-coupler (U1) is connected.

2. The common cathode signal conversion circuit for a fiscal circuit breaker according to claim 1, wherein: the common cathode signal conversion circuit for the fiscal circuit breaker further comprises a capacitor C1, and the capacitor C1 is connected between the gate and the source of the NMOS transistor V1.

3. The common cathode signal conversion circuit for a fiscal circuit breaker according to claim 1, wherein: the common cathode signal conversion circuit for the fiscal circuit breaker further comprises a capacitor C2, and the capacitor C2 is connected between the gate and the source of the NMOS transistor V2.

4. The common cathode signal conversion circuit for a fiscal circuit breaker according to claim 1, wherein: the current transmission ratio of the optical coupler (U1) is 300-600%.

5. The common cathode signal conversion circuit for a fiscal circuit breaker according to claim 1, wherein: the resistor R1, the resistor R2, the resistor R3, the resistor R4 and the resistor R5 are in megaohm.