CN111711166A

CN111711166A - Method for automatically protecting overvoltage or undervoltage protection circuit

Info

Publication number: CN111711166A
Application number: CN202010684080.2A
Authority: CN
Inventors: 夏乾华
Original assignee: Ausemi Shenzhen Co ltd
Current assignee: Ausemi Shenzhen Co ltd
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2020-09-25

Abstract

The invention provides a circuit protection method for automatically detecting alternating current or direct current voltage by using an electronic switch circuit to perform overvoltage or undervoltage protection. The alternating current or direct current voltage at the input end of an electric appliance or a user or the output end of a power supply system is directly rectified and filtered into direct current voltage (the input is the direct current voltage without rectification and filtering treatment) and is not reduced by a resistance-capacitance voltage reduction or a transformer, the direct current voltage after rectification and filtering is directly detected, and after the overvoltage or undervoltage condition is detected, a detection circuit sends out a driving signal to start a protection switch to directly cut off the input voltage entering a load or simultaneously send out an alarm signal to an alarm circuit to warn the user. The method can reduce the volume and power consumption of the protection circuit, is more favorable for circuit integration, miniaturization and cost reduction, is more favorable for being built in a protected electric appliance to be made into a protection circuit accessory with a micro volume, reduces the protection delay time, and ensures quicker and safer protection.

Description

Method for automatically protecting overvoltage or undervoltage protection circuit

Technical Field

The invention belongs to the field of power electronic circuit design, and particularly relates to a method for automatically detecting alternating current or direct current voltage by using an electronic switch circuit and automatically protecting an overvoltage or undervoltage protection circuit.

Background

The current voltage detection and over-voltage and under-voltage protection circuit has the following method.

The AC voltage at the input end of an electric appliance or a user is rectified and filtered into DC voltage after being converted into low-voltage AC voltage by resistance-capacitance voltage reduction or transformer voltage reduction, the rectified and filtered DC voltage is detected, and the detection circuit sends a driving signal to drive a protection circuit after detecting that an overvoltage or undervoltage condition occurs so as to start the protection circuit.

The detection protection circuit is large in size due to the fact that resistance-capacitance voltage reduction or transformer voltage reduction elements are various and large in size, and high-voltage capacitance generates heat due to loss angle, resistance electric energy loss and transformer iron core loss, so that electric energy loss is large and heat is large. If the protection circuit requires a large driving current, the rc step-down is costly and difficult to support. The major disadvantage is that it is difficult to integrate and miniaturize, and it is difficult to use products such as small household electrical appliances, etc. which need to integrate with other circuits and embed protection circuits, and it can only be made into external fittings or increase the volume of the product, which also affects the beauty of the product and reduces the usability.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for directly rectifying and filtering alternating current or direct current voltage at the input end of an electric appliance or a user or the output end of a power supply system into direct current voltage (the input is direct current voltage and is not subjected to rectifying and filtering processing), directly detecting the direct current voltage which is only rectified and filtered without resistance-capacitance voltage reduction or voltage reduction of a transformer, and sending a driving signal by a detection circuit after detecting the overvoltage or undervoltage condition so as to start a protection switch to directly cut off the input voltage entering a load or simultaneously sending an alarm signal to an alarm circuit to warn the user.

The method can reduce the volume and power consumption of the protection circuit, is more favorable for circuit integration, miniaturization and cost reduction by combining a high-voltage semiconductor technology, is more favorable for the integrated design of a protection circuit accessory which is built in a protected electric appliance and is made into a micro volume or is integrated with other product circuits, reduces the protection delay time, and ensures that the protection is quicker and safer.

On the first hand, the DC voltage of the AC or DC voltage at the input end of the user or the output end of the power supply system is detected, and after the overvoltage or undervoltage condition is detected, the detection circuit sends out a driving signal to start a protection switch to directly cut off the input voltage entering the load or send out an alarm signal to an alarm circuit to warn the user.

Preferably, the detected voltage is directly rectified and filtered if the detected voltage is alternating current, and is not subjected to resistance or transformer step-down processing.

Preferably, the detected voltage is not subjected to rectification filtering if the detected voltage is direct current, and is not subjected to resistance or transformer voltage reduction processing.

Preferably, the detection circuit sends a driving signal after detecting the occurrence of the over-voltage or under-voltage condition, and activates an electronic protection switch (the switch may be a relay or a semiconductor electronic switch) to directly cut off the input voltage into the load or simultaneously send an alarm signal to the alarm circuit.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

Fig. 1 is a schematic diagram of a circuit protection method for performing an overvoltage or undervoltage protection by using an electronic switching circuit to automatically perform ac voltage detection.

Note that U1 Voltage detection Circuit

Bridge1 rectifier circuit, here shown as a full-wave rectifier, may be a half-wave rectifier circuit

SW1 semiconductor switch

SW2 Relay switch

Load1 resistive Load

Load2 inductive Load

Load3 other Load devices

The solutions of Load1, Load2, and Load3 are illustrative and may be controlled by a relay or a semiconductor switch.

The U1, the Bridge1, and the SW1 may be formed by integrated circuits combined with each other, or may be formed by combining two of 3 integrated circuits, or by combining 3 integrated circuits, or may be formed by discrete component circuits.

Fig. 2 is a schematic diagram of a circuit protection method for performing an overvoltage or undervoltage protection by using an electronic switch circuit to automatically perform ac voltage detection according to an embodiment of the present invention.

Note that U1 Voltage detection Circuit

SW1 semiconductor switch

SW2 Relay switch

Load1 resistive Load

Load2 inductive Load

Load3 other Load devices

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby. It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

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 is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to a determination" or "in response to a detection". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".

Example (b):

the circuit protection method utilizes the electronic switch circuit to automatically detect the alternating current or direct current voltage and carry out overvoltage or undervoltage protection.

Preferably, the dc voltage of the ac or dc voltage at the user input terminal or the output terminal of the power supply system is detected, and the detection circuit sends a driving signal after detecting that the overvoltage or undervoltage condition occurs, so as to start the protection switch to directly cut off the input voltage entering the load or send an alarm signal to the alarm circuit to warn the user.

Preferably, the detected voltage is direct current, does not need rectification filtering, and is not subjected to resistance or transformer voltage reduction processing.

For the sake of brief description, the method provided by the embodiment of the present invention may refer to the corresponding contents in the foregoing product embodiments.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.

Claims

1. A circuit protection method for automatic AC or DC voltage detection and overvoltage or undervoltage protection by electronic switch circuit features that the AC or DC voltage at user input or output of power supply system is detected, and after the overvoltage or undervoltage is detected, a drive signal is sent out by the detection circuit to start the protection switch to cut off the input voltage to load or simultaneously to send out alarm signal to alarm circuit for warning user.

2. A circuit protection method for over-voltage or under-voltage protection by automatic AC or DC voltage detection with electronic switch circuit according to claim 1, characterized in that if the detected voltage is AC, it is rectified and filtered directly without resistance or transformer step-down.

3. A circuit protection method for overvoltage or undervoltage protection by automatic ac or dc voltage detection using an electronic switching circuit according to claim 1, characterized in that the detected voltage is dc without rectification filtering and without resistance or transformer step-down.

4. A circuit protection method for overvoltage or undervoltage protection by automatic ac or dc voltage detection by means of an electronic switching circuit, according to claim 1, characterized in that the detection circuit sends a drive signal after the occurrence of an overvoltage or undervoltage condition is detected, and the electronic protection switch (which may be a relay or a semiconductor electronic switch) is activated to cut off the input voltage to the load directly or simultaneously send an alarm signal to the alarm circuit.