CN203932969U - A kind of low-voltage leakage protector with over-voltage protecting function - Google Patents

Abstract

The utility model discloses a kind of low-voltage leakage protector with over-voltage protecting function; comprise in low-voltage leakage protector and low-voltage leakage protector and produce the experiment button in loop for being communicated with simulation leakage current; node at experiment button two ends is in parallel for being communicated with the electronic switch in simulation leakage current generation loop; also comprise the over-voltage detection circuit between the node that is parallel to experiment button two ends; in the time that the input voltage of low-voltage leakage protector transfinites, over-voltage detection circuit output is greater than the voltage control electronic switch conducting of electronic switch threshold value.The utility model can be realized over-voltage protecting function, the feature such as have reliable operation, circuit structure is simple, and cost of manufacture is low, use is safe.

Description

A low-voltage leakage protector with overvoltage protection function

technical field

The invention relates to a low-voltage protection switch, in particular to a low-voltage leakage protector.

Background technique

The currently used low-voltage leakage protection switch has only overcurrent and leakage protection functions, but no overvoltage protection function. Once overvoltage occurs on the low-voltage lighting line (for example: 1. When replacing the low-voltage side busbar of the transformer, the neutral wire is wrongly connected to the live wire; 2. The neutral wire is blown due to overcurrent or poor contact, and lightning strikes overvoltage, etc.) A large number of household appliances will be burned, which will not only cause great economic losses to users but also cause disputes between users and power companies.

Contents of the invention

The technical problem to be solved by the present invention is to provide a low-voltage leakage protector with overvoltage protection function. The present invention has the characteristics of reliable operation, simple circuit structure, low production cost and safe use.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A low-voltage leakage protector with overvoltage protection function, including the low-voltage leakage protector and the experimental button used to connect the analog leakage current generation circuit in the low-voltage leakage protector, and the nodes at both ends of the experimental button are connected in parallel to connect the analog leakage current generation The electronic switch of the loop also includes an overvoltage detection circuit connected in parallel between the nodes at both ends of the experimental button. When the input voltage of the low-voltage leakage protector exceeds the limit, the overvoltage detection circuit outputs a voltage greater than the threshold of the electronic switch to control the electronic switch.

The present invention is further improved in that:

The electronic valve device of the electronic switch is a bidirectional thyristor Q1; the overvoltage detection circuit is a resistor divider composed of a resistor R1 and a resistor R2 in series, the resistor R1 is located at the low potential end, and the divided voltage on the resistor R1 is output to the bidirectional controllable Silicon Gate of Q1.

The resistor R1 is preferably an adjustable resistor.

A capacitor C1 is connected in parallel to the nodes at both ends of the resistor R1.

The beneficial effects produced by adopting the above-mentioned technical scheme are:

A low-voltage leakage protector with an overvoltage protection function provided by the present invention controls the on-off of the electronic switch by detecting whether the input voltage of the leakage protector exceeds the limit through an overvoltage detection circuit, thereby controlling the path and disconnection of the analog leakage current generation circuit ( Equivalent to the opening and closing of the experimental button), when the input voltage exceeds the limit, the leakage protector trips and cuts off the power supply, which plays the role of overvoltage protection. The invention has the characteristics of reliable operation, simple circuit structure, low production cost, safe use and the like.

Description of drawings

Fig. 1 is a schematic diagram of the circuit structure of the present invention.

Detailed ways

It can be known from the embodiment shown in Figure 1 that this embodiment includes a low-voltage leakage protector and an experimental button used to communicate with the analog leakage current generation circuit in the low-voltage leakage protector, and the nodes at both ends of the experimental button are connected in parallel for connection with the analog leakage current generation. The electronic switch of the loop also includes an overvoltage detection circuit connected in parallel between the nodes at both ends of the experimental button. When the input voltage of the low-voltage leakage protector exceeds the limit, the overvoltage detection circuit outputs a voltage greater than the threshold of the electronic switch to control the electronic switch.

The electronic valve device of the electronic switch in this embodiment is triac Q1; the overvoltage detection circuit is a resistor divider composed of resistor R1 and resistor R2 connected in series, resistor R1 is located at the low potential end, and the divided voltage output on resistor R1 To the gate of triac Q1.

In this embodiment, the resistor R1 is an adjustable resistor.

In this embodiment, the nodes at both ends of the resistor R1 are connected in parallel with the capacitor C1.

working principle:

The overvoltage protection part is composed of bidirectional thyristor Q1, adjustable resistor R1, resistor R2, and capacitor C1. Connect it in parallel to the two ends of the original leakage protector test button S1 (there is a voltage equal to the input terminal of the leakage protector before the test button S1 is not pressed). When the voltage is normal, it is divided by the adjustable resistor R1 and the resistor R2 (this voltage can be adjusted by R1), and the voltage dropped on the adjustable resistor R1 is not enough to trigger the conduction of Q1, so it has no effect on the circuit of the analog leakage current ( In the open circuit state), the protector operates normally. When the line overvoltage is caused by some reason (such as: wrong phase, neutral line disconnection, lightning, etc.), the voltage dropped on the adjustable resistor R1 is greater than the electronic switch threshold, which is enough to trigger the bidirectional thyristor Q1 to conduct. After the bidirectional thyristor Q1 is turned on, the analog leakage current generation circuit is in the open state, which is equivalent to pressing the test button S1, and then the protector trips to cut off the power supply, which plays the role of overvoltage protection.

Claims (4)

1. A low-voltage leakage protector with overvoltage protection function, comprising a low-voltage leakage protector and an experimental button used to communicate with the analog leakage current generation loop in the low-voltage leakage protector, characterized in that: the nodes at the two ends of the experimental button Parallel connection is used to connect the electronic switch of the analog leakage current generation circuit, and also includes an overvoltage detection circuit connected in parallel between the nodes at both ends of the experimental button. When the input voltage of the low-voltage leakage protector exceeds the limit, the output of the overvoltage detection circuit is greater than the electronic switch. The voltage at the switching threshold controls the conduction of the electronic switch. 2. A low-voltage leakage protector with overvoltage protection function according to claim 1, characterized in that the electronic valve device of the electronic switch is a bidirectional thyristor Q1; the overvoltage detection circuit is composed of a resistor R1 A resistor divider formed in series with the resistor R2, the resistor R1 is located at the low potential end, and the divided voltage on the resistor R1 is output to the control electrode of the bidirectional thyristor Q1. 3. A low-voltage leakage protector with overvoltage protection function according to claim 2, characterized in that said resistor R1 is an adjustable resistor. 4. A low-voltage leakage protector with overvoltage protection function according to claim 2 or 3, characterized in that a capacitor C1 is connected in parallel at the node at both ends of the resistor R1.