CN210867160U - A universal protection circuit - Google Patents

Abstract

The embodiment of the utility model relates to a universal protection circuit, comprising an electrical control device, a first resistor, a second resistor, a first diode, a second diode, a voltage regulator, a first electrolytic capacitor, and an optocoupler device , power input terminal and output terminal, the output terminal is used to connect with the load. When the load has abnormal voltage, current, working overtime, leakage, etc. during use, the resistance of the second resistance can be reduced through the optocoupler device, and the current of the DC circuit can be increased, so that the voltage flowing through the coil of the electric control device reaches the driving voltage. The electric control device starts to cut off the power supply to the load, so that the entire load is in a power-off state, which effectively prevents the safety hazard caused by abnormal load. The universal protection circuit can automatically recover after unplugging the electrical plug of the load or completely cutting off the power supply of the load, thereby improving its safety. It solves the technical problem of not cutting off the power supply when the existing electrical equipment or electrical appliances are abnormal, and dealing with the potential safety hazards brought by the electrical equipment or electrical appliances during the abnormal process.

Description

A universal protection circuit

technical field

The utility model relates to the technical field of electrical protection circuits, in particular to a universal protection circuit.

Background technique

In view of the existence of some unstable factors in the power circuit of existing electrical equipment or electrical appliances, a circuit designed to prevent such unstable factors from affecting the circuit effect is called a protection circuit. Existing protection circuits include protection circuits such as overcurrent protection, overvoltage protection, overheating protection, no-load protection, and short circuit protection.

The reset in the protection circuit is divided into automatic (active) reset and artificial (passive) reset. Most of the passive reset protection circuits have a reset switch, and the structure is basically mechanical, but most passive reset protection circuits in the market often have automatic resets. Abnormal, such as current protection switch, its structure is composed of a double or several layers of metal sheets with different thermal expansion coefficients inside the switch. When the current passing through this metal sheet is too large, the metal sheet will heat up and expand and deform instantly, triggering the After the point is disconnected and protected, part of the circuit is powered off, but because the metal sheet is a physical structure, there is a risk of automatic reset when the temperature drops. There are certain safety hazards in the maintenance or troubleshooting of electrical appliances.

Therefore, in view of the above situation, how can electrical equipment or electrical appliances be automatically cut off from the main power supply of electrical appliances when abnormal voltage, current, work overtime, leakage, etc. The potential safety hazard caused by the exception has become an important technical problem to be solved urgently by those skilled in the art.

Utility model content

The embodiment of the present utility model provides a universal protection circuit, which is used to solve the technical problem of not cutting off the power supply when the existing electrical equipment or electrical equipment is abnormal, and to deal with the potential safety hazards brought by the electrical equipment or electrical equipment during the abnormal process.

In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:

A universal protection circuit, applied to electrical equipment or electrical appliances, includes a DC circuit, an electrical control device, a second resistor, a voltage regulator, a first electrolytic capacitor, an optocoupler device, a power input end and an output end, the the DC loop includes a first resistor, a first diode and a second diode;

The first end of the electric control device is connected to the first end of the power input end, the second end of the electric control device is connected to the output end, the voltage regulator tube and the first electrolytic capacitor are respectively connected to The third end and the fourth end of the electrical control device are connected in parallel, the third end of the electrical control device is also connected to the cathode of the first diode, and the anode of the first diode is connected in series with the The first resistor is connected to the first end of the power input end, the second end of the power input end is connected to the anode of the second diode and the first end of the second resistor, respectively, and the second two The cathode of the electrode tube is connected to the anode of the first electrolytic capacitor, the second end of the second resistor is connected to the cathode of the first electrolytic capacitor, and the first end of the optocoupler device is connected to the second resistor parallel connection;

Wherein, the output terminal is used for connecting with the load.

Preferably, the electrical control device is a relay.

Preferably, the universal protection circuit further includes a current detection circuit and a varistor; the second end of the optocoupler device is connected to the current detection circuit, and the input end of the current detection circuit is connected to the output end , the output terminal of the current detection circuit is connected in series with the load and the second terminal of the power input terminal, and the varistor is connected in parallel with the power input terminal.

Preferably, the current detection circuit includes a transformer, a fourth diode connected in parallel with the secondary winding of the transformer, a second electrolytic capacitor and a fifth resistor, and the cathode of the fourth diode is connected to the third diode. The anode of the tube is connected, and the cathode of the third diode is connected to the anode of the second electrolytic capacitor.

Preferably, the universal protection circuit further includes a time-out protection circuit, and the time-out protection circuit is respectively connected to the output end, the second end of the power input end and the second end of the optocoupler device.

Preferably, the overtime protection circuit includes a micro-control unit and a bridge rectifier bridge connected to the micro-control unit, the micro-control unit is also connected to the second end of the optocoupler device, the bridge rectifier bridge The input end of the power supply is respectively connected with the output end and the second end of the power input end.

Preferably, the universal protection circuit further includes a leakage protection circuit, and the leakage protection circuit is respectively connected to the output terminal, the second terminal of the power input terminal and the second terminal of the optocoupler device.

Preferably, the leakage protection circuit includes a leakage coil, a bridge rectifier bridge, a leakage chip and a triode, and the second end of the power input end passes through the leakage coil and is respectively connected with the first end and the third end of the bridge rectifier bridge. The first end of the load is connected, the output end is respectively connected to the second end of the bridge rectifier bridge and the second end of the load through the leakage coil, and the third end of the bridge rectifier bridge is connected to the power terminal of the leakage chip, the control terminal of the leakage chip is connected to the base of the triode, the collector of the triode is connected to the second end of the optocoupler device, and the bridge rectifier bridge The fourth terminal and the emitter of the triode are both grounded.

The utility model also provides a universal protection circuit, which is applied to electrical equipment or electrical appliances, comprising a DC circuit, an electrical control device, a second resistor, a voltage regulator, a first electrolytic capacitor, a power input end and an output end, all of which are The DC loop includes a first resistor, a first diode and a second diode;

The first end of the electric control device is connected to the first end of the power input end, the second end of the electric control device is connected to the output end, the voltage regulator tube and the first electrolytic capacitor are respectively connected to The third end and the fourth end of the electrical control device are connected in parallel, the third end of the electrical control device is also connected to the cathode of the first diode, and the anode of the first diode is connected in series with the The first resistor is connected to the first end of the power input end, the second end of the power input end is connected to the anode of the second diode and the first end of the second resistor, respectively, and the second two The cathode of the pole tube is connected to the anode of the first electrolytic capacitor, and the second end of the second resistor is connected to the cathode of the first electrolytic capacitor;

Wherein, the output terminal is used for connecting with the load.

Preferably, the electrical control device is a relay.

As can be seen from the above technical solutions, the embodiments of the present utility model have the following advantages:

1. The universal protection circuit is composed of an electrical control device, a first resistor, a second resistor, a first diode, a second diode, a voltage regulator tube, a first electrolytic capacitor, an optocoupler device, a power input terminal and an output The output terminal is used to connect with the load, and the voltage of the second resistor is adjusted by the optocoupler device to control the current of the DC loop, so as to control the voltage flowing through the coil of the electric control device to turn on or off the electric control device, so as to cut off the power supply to the load. When the load has abnormal voltage, current, working overtime, leakage, etc. during use, the resistance of the second resistor can be reduced through the optocoupler device, and the current of the DC circuit can be increased, so that the voltage flowing through the coil of the electric control device reaches the driving voltage. , The coil of the electric control device is driven to start to cut off the power supply to the load, so that the entire load is in a power-off state, effectively preventing the safety hazard caused by abnormal load. In addition, the universal protection circuit also has a passive reset function. When the universal protection circuit is triggered, the whole universal protection circuit can be restored only after the fire or neutral line of the main power supply of the load is disconnected, which can effectively prevent forgetting to unplug when the load is abnormal. Turn off the power to deal with the potential safety hazards caused by the automatic reset of other types of protection electronic devices during the abnormal process. Hidden technical problems;

2. Compared with the existing current protection circuit, the universal protection circuit can recover automatically after the electrical plug of the load is unplugged or the power supply of the load is completely cut off, which improves its safety.

Description of drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are just some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative labor.

FIG. 1 is a schematic circuit diagram of Embodiment 1 of the universal protection circuit according to the embodiment of the present invention.

FIG. 2 is a schematic circuit diagram of the second embodiment of the universal protection circuit according to the embodiment of the present invention.

FIG. 3 is a schematic circuit diagram of the third embodiment of the universal protection circuit according to the embodiment of the present invention.

FIG. 4 is a schematic circuit diagram of the fourth embodiment of the universal protection circuit according to the embodiment of the present invention.

FIG. 5 is a schematic circuit diagram of the fifth embodiment of the universal protection circuit according to the embodiment of the present invention.

Detailed ways

In order to make the invention purpose, features and advantages of the present utility model more obvious and understandable, the technical solutions in the embodiments of the present utility model will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, , the embodiments described below are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The embodiment of the present application provides a general-purpose protection circuit, which is used to solve the technical problem of not cutting off the power supply when the existing electrical equipment or electrical appliance is abnormal, and to deal with the potential safety hazard brought by the electrical equipment or electrical appliance during the abnormal process.

Example 1:

The embodiment of the present utility model provides a general-purpose protection circuit, which is applied to electrical equipment or electrical appliances, and is mainly used for household appliances such as refrigerators, televisions, and air conditioners. As shown in FIG. 1 , FIG. The circuit schematic diagram of the first embodiment of the universal protection circuit described above.

The embodiment of the present utility model provides a universal protection circuit, which includes a DC circuit, an electrical control device RLY, a second resistor R2, a voltage regulator ZD1, a first electrolytic capacitor C1, an optocoupler device U1, a power input end and an output end OUT-L, the DC loop includes a first resistor R1, a first diode D1 and a second diode D2;

The first end of the electric control device RLY is connected to the first end IN-L of the power input end, the second end of the electric control device RLY is connected to the output end OUT-L, and the voltage regulator ZD1 and the first electrolytic capacitor C1 are respectively connected to the electric control device. The third end and the fourth end of the device RLY are connected in parallel, the third end of the electrical control device RLY is also connected to the cathode of the first diode D1, and the anode of the first diode D1 is connected in series with the first resistor R1 and the power supply input end. The first terminal IN-L is connected, the second terminal N of the power input terminal is respectively connected to the anode of the second diode D2 and the first terminal of the second resistor R2, and the cathode of the second diode D2 is connected to the first electrolytic capacitor C1 The anode of the second resistor R2 is connected to the cathode of the first electrolytic capacitor C1, and the first end of the optocoupler device U1 is connected in parallel with the second resistor R2.

It should be noted that the electrical control device RLY may be a normally closed relay, or may be other electrical control devices having the same working principle as the relay. The second terminal N of the power input terminal is the neutral wire of the power supply, and the first terminal IN-L of the power input terminal and the output terminal OUT-L are the live wire of the power supply. The output terminal OUT-L is connected to the load. The second end of the optocoupler device U1 is pins 1 and 2 of the optocoupler device U1, and the first end of the optocoupler device U1 is pins 4 and 6 of the optocoupler device U1.

The general-purpose protection circuit of the embodiment of the present invention has few electronic components and is suitable for any type of circuit protection. Different types of protection only need to change the front-end trigger signal. The universal protection circuit can be set on a circuit board, or the universal protection circuit can be set on a circuit board such as a power supply or a controller of an electrical appliance.

In the embodiment of the present invention, the optocoupler device U1 is also connected to a controller, and the controller is used to trigger the operation of the optocoupler device U1. Wherein, the controller may be a single chip microcomputer, or may be a circuit capable of starting the operation of the optocoupler device U1.

The working principle of the universal protection circuit of the first embodiment of the present utility model is as follows: the electric control device RLY is preferentially connected in series with the live wire of the power supply, the first end of the electric control device RLY is connected to the first end IN-L of the power input end, and the other electric control device The second terminal of RLY is connected to the output terminal OUT-L, and the output terminal OUT-L is connected to the load. During normal operation, the RLY contact of the electric control device is pulled in, and the first terminal IN-L of the power input end is connected to the output end OUT-L. When the protection is triggered, the RLY coil of the electric control device is activated and the RLY contact of the electric control device is activated through the internal mechanical structure. Disconnect, cut off the electrical power supply. The loop in the entire universal protection circuit keeps the electrical control device RLY in the open state of the contacts, which can only be restored when the entire universal protection circuit is completely powered off.

The first terminal of the first resistor R1 is connected to the first terminal IN-L of the power input terminal, the second terminal of the first resistor R1 is connected to the anode of the first diode D1, and the anode of the second diode D2 is connected to the first terminal of the power input terminal. Two terminals N, the cathode of the second diode D2 is connected to the cathode of the first diode D1, forming a simple resistor to step down and rectify it into a DC voltage and form a DC loop, the second resistor R2 is connected in series with the negative of the DC loop Extreme, play the role of current limiting. The DC loop is connected in parallel with pins 4 and 6 of the optocoupler device U1. The voltage regulator tube ZD1 and the first electrolytic capacitor C1 are connected in parallel to both ends of the coil of the electric control device RLY, and the two ends are respectively the positive and negative poles of the DC loop after the voltage reduction of the second resistor R2. The first electrolytic capacitor C1 has the function of filtering and storing electric energy, which can stabilize the voltage of the coil of the electric control device RLY, and the voltage regulator ZD1 can control the voltage of the coil of the electric control device RLY within a safe range to prevent the voltage of the coil in the electric control device RLY from being too high. and damaged. It should be noted that the DC circuit is mainly used to provide driving power for the coil of the electrical control device RLY.

When the general protection circuit is not triggered, the voltage across the electrical control device RLY or the passing current can only maintain the state of the relay, but cannot trigger the electrical control device RLY to work. When the load is in an abnormal state such as voltage, current, timeout, leakage The controller connected to the 1 and 2 pins of the optocoupler device U1 can light up the internal photodiode and trigger the 4th and 6th pins of the optocoupler device U1 to turn on. At this time, the resistance across the second resistor R2 decreases, so that the current of the DC loop increases. The voltage at both ends of the RLY coil of the electric control device conforms to its driving voltage, and the RLY coil of the electric control device starts to disconnect the RLY contact of the electric control device through the internal mechanical structure, cutting off the live wire power supply of the load.

Since the circuit connected to the load is open, the load is in a no-power state, the voltage of the 1 and 2 pins of the optocoupler device U1 disappears (that is, there is no voltage), and the 4th and 6th pins of the optocoupler device U1 form a high-impedance state. , the universal protection circuit continues to form a DC loop through the second resistor R2, the voltage and current of the entire DC loop continue to maintain the coil of the electric control device RLY in working state, and the contact of the electric control device RLY remains disconnected.

It should be noted that the universal protection circuit appropriately adjusts the specifications of the first resistor R1, the second resistor R2 and the voltage regulator tube ZD1 through the coil parameters of the electrical control device RLY, so that the circuit has the ability to trigger and hold the coil of the electrical control device RLY. voltage or current.

The utility model provides a universal protection circuit through an electrical control device, a first resistor, a second resistor, a first diode, a second diode, a voltage regulator tube, a first electrolytic capacitor, an optocoupler device, a power supply Input terminal and output terminal, the output terminal is used to connect with the load, and the voltage of the second resistor is adjusted through the optocoupler device to control the current of the DC loop, so as to control the voltage flowing through the coil of the electrical control device to turn on or off the electrical control device to achieve whether Cut off the power supply to the load. When the load has abnormal voltage, current, working overtime, leakage, etc. during use, the resistance of the second resistor can be reduced through the optocoupler device, and the current of the DC circuit can be increased, so that the voltage flowing through the coil of the electric control device reaches the driving voltage. , The coil of the electric control device is driven to start to cut off the power supply to the load, so that the entire load is in a power-off state, effectively preventing the safety hazard caused by abnormal load. In addition, the universal protection circuit also has a passive reset function. When the universal protection circuit is triggered, the whole universal protection circuit can be restored only after the fire or neutral line of the main power supply of the load is disconnected, which can effectively prevent forgetting to unplug when the load is abnormal. Turn off the power to deal with the potential safety hazards caused by the automatic reset of other types of protection electronic devices during the abnormal process. Hidden technical issues.

Embodiment 2:

FIG. 2 is a schematic circuit diagram of the second embodiment of the universal protection circuit according to the embodiment of the present invention.

The second embodiment is based on the general-purpose protection circuit provided in the first embodiment by adding a current detection circuit and a varistor VDR. The load in the general-purpose protection circuit of the embodiment of the present invention is an electric product. The general-purpose protection circuit mainly plays the role of current protection in the load. In the existing load circuit, three methods are mainly used for current protection: a current fuse, a PTC mechanical current fuse and a PPTC thermistor. Electric products often have motor stalls during use. The use of traditional current fuses can easily cause the fuse to burst. The load must be repaired before it can continue to be used, which will cause a lot of inconvenience to the user experience; electric products are often used during use. The motor will be blocked. If the PTC mechanical current insurance is used due to its mechanical structure defect, if you forget to pull out the plug in the process of abnormal processing, the PTC mechanical current insurance will have a certain risk of self-reset, and there will be hidden dangers to the safety of users; Electric products often have motor stalls during use. The use of PPTC thermistors will not have the above two types of problems, but their working methods are physical changes, and there will still be a weak current in the entire circuit after protection. , rather than isolation protection.

The universal protection circuit of the embodiment of the present invention further includes a current detection circuit and a varistor VDR; the second end of the optocoupler device U1 is connected to the current detection circuit, the input end of the current detection circuit is connected to the output end OUT-L, and the current The output terminal of the detection circuit is connected in series with the load and the second terminal N of the power input terminal, and the varistor VDR is connected in parallel with the power input terminal. The current detection circuit includes a transformer CT1, a fourth diode D4 connected in parallel with the secondary winding of the transformer CT1, a second electrolytic capacitor C2 and a fifth resistor R5, and the cathode of the fourth diode D4 is connected to the third diode D3. The anode is connected, and the cathode of the third diode D3 is connected to the anode of the second electrolytic capacitor C2.

It should be noted that the transformer CT1 may be a T-type transformer or a ring-type transformer (passing through the transformer coil). Both ends of the fifth resistor R5 are connected to the optocoupler device U1. The second end of the optocoupler device U1 is pins 1 and 2 of the optocoupler device U1, and the first end of the optocoupler device U1 is pins 4 and 6 of the optocoupler device U1.

The working principle of the universal protection circuit of the second embodiment of the present utility model is as follows:

The output terminal OUT-L is connected to the load through the electrical control device RLY of the universal protection circuit and then connected to the transformer CT1. When the load is working, the working current of the load flows through the transformer CT1, and the transformer CT1 converts the current flowing through the transformer CT1 into a voltage according to the principle of electromagnetic induction, and then rectifies through the third diode D3 and the fourth diode D4. It is converted into direct current and filtered through the second electrolytic capacitor C2.

When the current of the load is too high, the voltage converted by the current detection circuit also increases. At this time, the voltage of the current in the current detection circuit drives the optocoupler device U1 to light up the internal photodiode and trigger the optocoupler device U1 on. At this time, the resistance at both ends of the second resistor R2 decreases, and the current in the entire DC loop increases. The voltage at both ends of the RLY coil of the electric control device conforms to its driving voltage, and the coil of the electric control device RLY starts to disconnect the contact of the electric control device RLY through the internal mechanical structure, cutting off the connection between the load and the output terminal OUT-L, and the whole load is in a no-electric state. The voltage of the current detection circuit disappears, and the voltage between pins 1 and 2 of the optocoupler device U1 also disappears, and the pins 4 and 6 of the optocoupler device U1 form a high-impedance state, and the general protection circuit continues to pass through the second resistor. R2 forms a loop, the entire loop voltage and current continue to maintain the coil of the electric control device RLY in working state, and the contact of the electric control device RLY remains disconnected, so that the circuit in the load and the electronic components of the general-purpose protection circuit will not be affected by The increased load will damage the device and improve the safety of the use environment. Compared with the existing current protection circuit, the universal protection circuit can recover automatically after the electrical plug of the load is unplugged or the power supply of the load is completely cut off, thereby improving its safety.

Embodiment three:

FIG. 3 is a schematic circuit diagram of the third embodiment of the universal protection circuit according to the embodiment of the present invention.

The third embodiment is based on the general-purpose protection circuit provided in the first embodiment by adding a time-out protection circuit. The loads in the general-purpose protection circuit of the embodiment of the present utility model are mainly electric heating types, such as toasters, electric kettles, etc. The universal protection circuit of the embodiment of the utility model mainly plays the role of overtime protection in the load. Most of the existing load protection circuits do not have a timeout protection circuit. When the circuit components of the load are abnormal or due to external abnormal conditions, the load may be in a working state all the time, and the heating of the electronic components in the load for a long time will cause a fire hazard. .

Therefore, the universal protection circuit of the embodiment of the present invention further includes a time-out protection circuit, which is respectively connected to the output end OUT-L, the second end N of the power input end, and the second end of the optocoupler device U1; the time-out protection circuit includes The micro-control unit MCU and the bridge rectifier bridge connected with the micro-control unit MCU, the micro-control unit is also connected with the second end of the optocoupler device, and the input end of the bridge rectifier bridge is respectively connected with the output end and the second end of the power input end .

It should be noted that the second end of the optocoupler device U1 is pins 1 and 2 of the optocoupler device U1, and the first end of the optocoupler device U1 is pins 4 and 6 of the optocoupler device U1. The time-out protection circuit can be either a microcontroller unit MCU or a clock circuit. When the load working time reaches the maximum limit, the microcontroller MCU in the load circuit or a separate clock circuit triggers the second end of the optocoupler device U1 in the universal protection circuit to light up the internal photodiode and trigger the The first end of the optocoupler device U1 in the universal protection circuit is turned on. At this time, the resistance at both ends of the second resistor R2 decreases, and the current of the entire DC loop increases. The voltage at both ends of the RLY coil of the electric control device conforms to its driving voltage, and the RLY coil of the electric control device is activated to disconnect the contact of the electric control device RLY through the internal mechanical structure, cut off the connection between the load and the output terminal OUT-L, and the entire load is in a no-electric state. When the voltage of the current detection circuit disappears, the voltage between the second terminals of the optocoupler device U1 also disappears, and the first terminal of the optocoupler device U1 forms a high-impedance state. The general-purpose protection circuit continues to form a loop through the second resistor R2. The entire loop voltage and current continue to maintain the coil of the electric control device RLY in a working state, and the contacts of the electric control device RLY remain disconnected. Turn off the power of the load to achieve the protection effect and avoid the occurrence of fire hazards. Compared with the existing load protection circuit, the universal protection circuit can recover automatically after the electrical plug of the load is unplugged or the power supply of the load is completely cut off, thereby improving its safety.

The universal protection circuit in the third embodiment of the present invention is usually used in toasters. Since most toaster products on the market do not have time-out or overheat protection, the toaster products are also easily affected by external influences and get stuck up and down. The handle cannot rebound normally and the power is cut off, resulting in continuous heating and a safety hazard. The universal protection circuit in the third embodiment of the present invention can well avoid such potential safety hazards, and completely disconnect the power supply of the first terminal IN-L of the power input end, so that the toaster does not heat up in an abnormal situation, and avoids excessive heating. Stoves generate voltages that are harmful to humans.

Embodiment 4:

FIG. 4 is a schematic circuit diagram of the fourth embodiment of the universal protection circuit according to the embodiment of the present invention.

The fourth embodiment is based on the general-purpose protection circuit provided in the first embodiment by adding a current detection circuit and a varistor VDR. The load in the general-purpose protection circuit of the embodiment of the present utility model is mainly an electric water heater and other household appliances that heat water. The universal protection circuit of the embodiment of the present invention mainly plays the role of leakage protection in the load.

The universal protection circuit of the embodiment of the present invention further includes a leakage protection circuit, which is respectively connected to the output terminal OUT-L, the second terminal N of the power input terminal and the second terminal of the optocoupler device U1. The leakage protection circuit includes a leakage coil L, a bridge rectifier bridge BD, a leakage chip U2 and a triode Q1. The second end N of the power input end passes through the leakage coil L and is respectively connected with the first end of the bridge rectifier bridge BD and the first end of the load. Connection, the output end OUT-L is connected to the second end of the bridge rectifier bridge BD and the second end of the load respectively through the leakage coil L, and the third end of the bridge rectifier bridge BD is connected to the power end of the leakage chip U2, leakage current The control terminal of the chip U2 is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the second terminal of the optocoupler device U1, the fourth terminal of the bridge rectifier BD and the emitter of the transistor Q1 are both grounded.

It should be noted that the second end of the optocoupler device U1 is pins 1 and 2 of the optocoupler device U1, and the first end of the optocoupler device U1 is pins 4 and 6 of the optocoupler device U1.

The working principle of the universal protection circuit of the fourth embodiment of the present utility model is:

The second terminal N of the power input terminal and the output terminal OUT-L pass through the leakage coil L. When the load leaks, the current through the leakage coil L is not 0. At this time, the leakage chip U2 detects the leakage signal and outputs a high level to drive the transistor Q1. The transistor Q1 is turned on, and triggers the first end of the optocoupler device U1 in the universal protection circuit to be turned on. At this time, the resistance at both ends of the second resistor R2 decreases, and the current of the entire DC loop increases. The voltage at both ends of the RLY coil of the electric control device conforms to its driving voltage, and the RLY coil of the electric control device is activated to disconnect the contact of the electric control device RLY through the internal mechanical structure, cut off the connection between the load and the output terminal OUT-L, and the entire load is in a no-electric state. When the voltage of the current detection circuit disappears, the voltage between the second terminals of the optocoupler device U1 also disappears, and the first terminal of the optocoupler device U1 forms a high-impedance state. The general-purpose protection circuit continues to form a loop through the second resistor R2. The entire loop voltage and current continue to maintain the coil of the electric control device RLY in a working state, and the contacts of the electric control device RLY remain disconnected. Compared with the existing load protection circuit, the universal protection circuit can recover automatically after the electrical plug of the load is unplugged or the power supply of the load is completely cut off, thereby improving its safety.

Although there are many electrical products on the market with leakage protection functions, such as instant electric water heaters, their working method is to turn off the heating body of the water heater for the main control board chip, and cannot completely turn off the entire electrical power supply and control circuit. The circuit part is abnormal or leakage cannot be turned off. The general-purpose protection circuit in the embodiment of the present utility model can turn off the power supply provided to the load, so that the circuit of the load is completely powered off, and the general-purpose protection circuit can be automatically restored only by removing the abnormality manually. The design of the general-purpose protection circuit is applied to In terms of electrical products, the use of electrical products is safer and more reliable.

Embodiment 5:

FIG. 5 is a schematic circuit diagram of the fifth embodiment of the universal protection circuit according to the embodiment of the present invention.

The utility model provides a universal protection circuit, which is applied to electrical equipment or electrical appliances, and includes a DC circuit, an electrical control device RLY, a second resistor R2, a voltage regulator ZD1, a first electrolytic capacitor C1, and a power input terminal. and an output terminal, the DC loop includes a first resistor R1, a first diode D1 and a second diode D2;

The first end of the electric control device RLY is connected to the first end IN-L of the power input end, the second end of the electric control device RLY is connected to the output end OUT-L, and the voltage regulator ZD1 and the first electrolytic capacitor C1 are respectively connected to the electric control device. The third end and the fourth end of the device RLY are connected in parallel, the third end of the electrical control device RLY is also connected to the cathode of the first diode D1, and the anode of the first diode D1 is connected in series with the first resistor R1 and the power supply input end. The first end is connected, the second end N of the power input end is connected to the anode of the second diode D2 and the first end of the second resistor R2 respectively, the cathode of the second diode D2 is connected to the anode of the first electrolytic capacitor C1 , the second end of the second resistor R2 is connected to the cathode of the first electrolytic capacitor C1, the varistor VDR is connected in parallel with the power input end; the output end OUT-L is used to connect with the load.

It should be noted that the electrical control device RLY may be a normally closed relay, or may be other electrical control devices having the same working principle as the relay. The second terminal N of the power input terminal is the neutral wire of the power supply, and the first terminal IN-L of the power input terminal and the output terminal OUT-L are the live wire of the power supply. The output terminal OUT-L is connected to the load. The power input end is connected in parallel with the varistor VDR and then connected to the alternating current. Among them, the alternating current is preferably 220V mains.

The working principle of the general-purpose protection circuit of the fifth embodiment of the present utility model is:

When the voltage of the alternating current is higher than the safe voltage of the load, the voltage of the circuit of the universal protection circuit will increase accordingly, and at this time, the RLY coil of the electric control device can be driven, and the RLY coil of the electric control device can be activated to make the electric control device through the internal mechanical structure. The RLY contact is disconnected and the power supply to the load is cut off to ensure that the electronic components in the load or other components connected to the load will not be damaged due to overvoltage and ensure safety. After the voltage is stabilized, the universal protection circuit can be restored by unplugging the electrical plug of the load or completely cutting off the power supply of the load.

It should be noted that, when the protection voltage of the universal protection circuit is 250V, the resistance value of the first resistor R1 can be 3.5K 2W; the resistance value of the second resistor R2 can be 6.5K 2W.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above may refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present invention can be embodied in the form of a software product in essence, or the part that contributes to the prior art, or the whole or part of the technical solution, which is stored in a storage medium. , including several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, Read-Only Memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes .

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present utility model, but not to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be Modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention .

Claims (10)

1. a general-purpose protection circuit, applied to electrical equipment or electrical appliances, is characterized in that, comprises DC circuit, electric control device, second resistance, voltage regulator tube, first electrolytic capacitor, optocoupler device, power input terminal and an output terminal, the DC loop includes a first resistor, a first diode and a second diode; The first end of the electric control device is connected to the first end of the power input end, the second end of the electric control device is connected to the output end, the voltage regulator tube and the first electrolytic capacitor are respectively connected to The third end and the fourth end of the electrical control device are connected in parallel, the third end of the electrical control device is also connected to the cathode of the first diode, and the anode of the first diode is connected in series with the The first resistor is connected to the first end of the power input end, the second end of the power input end is connected to the anode of the second diode and the first end of the second resistor, respectively, and the second two The cathode of the electrode tube is connected to the anode of the first electrolytic capacitor, the second end of the second resistor is connected to the cathode of the first electrolytic capacitor, and the first end of the optocoupler device is connected to the second resistor parallel connection; Wherein, the output terminal is used for connecting with the load. 2 . The universal protection circuit according to claim 1 , wherein the electrical control device is a relay. 3 . 3. The universal protection circuit according to claim 1, wherein the universal protection circuit further comprises a current detection circuit and a varistor; the second end of the optocoupler device is connected to the current detection circuit , the input end of the current detection circuit is connected to the output end, the output end of the current detection circuit is connected in series with the load and the second end of the power supply input end, and the varistor is connected to the power supply input end connected in parallel. 4. The universal protection circuit according to claim 3, wherein the current detection circuit comprises a transformer, a fourth diode connected in parallel with the secondary winding of the transformer, a second electrolytic capacitor and a fifth resistor, the cathode of the fourth diode is connected to the anode of the third diode, and the cathode of the third diode is connected to the anode of the second electrolytic capacitor. 5 . The universal protection circuit according to claim 1 , wherein the universal protection circuit further comprises a time-out protection circuit, the time-out protection circuit is respectively connected with the output end and the second end of the power input end. 6 . connected to the second end of the optocoupler device. 6 . The universal protection circuit according to claim 5 , wherein the overtime protection circuit comprises a micro-control unit and a bridge rectifier bridge connected with the micro-control unit, and the micro-control unit is also connected with the The second end of the optocoupler device is connected, and the input end of the bridge rectifier bridge is respectively connected with the output end and the second end of the power input end. 7 . The universal protection circuit according to claim 1 , wherein the universal protection circuit further comprises a leakage protection circuit, and the leakage protection circuit is respectively connected with the output terminal and the second terminal of the power input terminal. 8 . connected to the second end of the optocoupler device. 8 . The universal protection circuit according to claim 7 , wherein the leakage protection circuit comprises a leakage coil, a bridge rectifier bridge, a leakage chip and a triode, and the second end of the power input end passes through the leakage current. 9 . The coil is respectively connected with the first end of the bridge rectifier bridge and the first end of the load, and the output end passes through the leakage coil and is connected with the second end of the bridge rectifier bridge and the load respectively. The second terminal is connected, the third terminal of the bridge rectifier bridge is connected to the power terminal of the leakage chip, the control terminal of the leakage chip is connected to the base of the triode, and the collector of the triode is connected to the The second end of the optocoupler device is connected, and the fourth end of the bridge rectifier bridge and the emitter of the triode are both grounded. 9. A general-purpose protection circuit, applied to electrical equipment or electrical appliances, characterized in that it comprises a DC circuit, an electrical control device, a second resistor, a voltage regulator tube, a first electrolytic capacitor, a power input end and an output end, the DC loop includes a first resistor, a first diode and a second diode; The first end of the electric control device is connected to the first end of the power input end, the second end of the electric control device is connected to the output end, the voltage regulator tube and the first electrolytic capacitor are respectively connected to The third end and the fourth end of the electrical control device are connected in parallel, the third end of the electrical control device is also connected to the cathode of the first diode, and the anode of the first diode is connected in series with the The first resistor is connected to the first end of the power input end, the second end of the power input end is respectively connected to the anode of the second diode and the first end of the second resistor, the second two The cathode of the pole tube is connected to the anode of the first electrolytic capacitor, and the second end of the second resistor is connected to the cathode of the first electrolytic capacitor; Wherein, the output terminal is used for connecting with the load. 10. The universal protection circuit according to claim 9, wherein the electrical control device is a relay.

Images