CN112071699A - Electronic circuit - Google Patents

Electronic circuit Download PDF

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Publication number
CN112071699A
CN112071699A CN202010997415.6A CN202010997415A CN112071699A CN 112071699 A CN112071699 A CN 112071699A CN 202010997415 A CN202010997415 A CN 202010997415A CN 112071699 A CN112071699 A CN 112071699A
Authority
CN
China
Prior art keywords
load
relay
protection circuit
circuit
power supply
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010997415.6A
Other languages
Chinese (zh)
Inventor
王亚杰
钱沛
梁紫锋
周葆林
邓官珠
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Gree Electric Appliances Inc of Zhuhai
Original Assignee
Gree Electric Appliances Inc of Zhuhai
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Gree Electric Appliances Inc of Zhuhai filed Critical Gree Electric Appliances Inc of Zhuhai
Priority to CN202010997415.6A priority Critical patent/CN112071699A/en
Publication of CN112071699A publication Critical patent/CN112071699A/en
Pending legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
    • H01H47/22—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current for supplying energising current for relay coil
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
    • H01H47/001—Functional circuits, e.g. logic, sequencing, interlocking circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
    • H01H47/002—Monitoring or fail-safe circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage

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  • Emergency Protection Circuit Devices (AREA)

Abstract

The present disclosure provides an electronic circuit, and relates to the field of circuits. The electronic circuit provided by the present disclosure includes a power supply circuit and a protection circuit; the power supply circuit comprises a power supply, a load and a relay, wherein the power supply supplies power to the load under the condition that the relay is closed; the protection circuit is connected with the load in parallel, and the protection circuit and the load form a loop under the condition that the relay is disconnected. This is disclosed through increasing protection circuit, can absorb the induced electromotive force that the load produced when the relay is turn-off, receives the impact of induced electromotive force to lead to the contact to damage when having avoided the relay to effectively protect the contact of relay, promote the reliability and the security of relay.

Description

Electronic circuit
Technical Field
The present disclosure relates to the field of circuits, and more particularly, to an electronic circuit.
Background
With the technical development in the circuit field, a control system gradually puts higher requirements on control quality, the integration level of an integrated circuit is gradually improved, and low-voltage and low-power-consumption devices are gradually increased.
The use of a relay having passive contacts in an electrical circuit enables the relay to be improved in terms of electromagnetic compatibility, circuit reliability, circuit safety, and the like.
Disclosure of Invention
One technical problem that this disclosure solves is how to promote the reliability of relay.
According to one aspect of the present disclosure, there is provided an electronic circuit comprising a power supply circuit and a protection circuit; the power supply circuit comprises a power supply, a load and a relay, wherein the power supply supplies power to the load under the condition that the relay is closed; the protection circuit is connected with the load in parallel, and the protection circuit and the load form a loop under the condition that the relay is disconnected.
In some embodiments, the protection circuit includes a dc protection circuit and an ac protection circuit; under the condition that the load is a direct current load and the power supply is a direct current power supply, the direct current protection circuit is switched on, and the alternating current protection circuit is switched off; when the load is an alternating current load and the power supply is an alternating current power supply, the alternating current protection circuit is switched on, and the direct current protection circuit is switched off.
In some embodiments, the protection circuit further comprises a load detection element and a gating circuit, the load detection element configured to: detecting whether the load is a direct current load or an alternating current load; under the condition that the load is detected to be a direct current load, controlling the gating circuit to switch on the direct current protection circuit and switch off the alternating current protection circuit; and under the condition that the load is detected to be an alternating current load, controlling the gating circuit to switch on the alternating current protection circuit and switch off the direct current protection circuit.
In some embodiments, the load detection element comprises an inductance and a first capacitance configured to: under the condition that the inductor is detected to form a path, determining that the load is a direct current load; in the case where it is detected that the first capacitance forms a path, the load is determined to be an alternating current load.
In some embodiments, the dc protection circuit includes a voltage dependent resistor or a bidirectional transient voltage suppression diode and the ac protection circuit includes a resistor and a second capacitor connected in series.
In some embodiments, the load is a dc load, the power source is a dc power source, and the protection circuit includes a voltage dependent resistor or a bi-directional transient voltage suppression diode.
In some embodiments, the load is an ac load, the power source is an ac power source, and the protection circuit includes a resistor and a second capacitor connected in series.
In some embodiments, the electronic circuit further comprises a relay drive circuit; the relay drive circuit includes: a relay coil configured to drive the relay to be closed or opened by the generated electromagnetic force; the relay control chip is electrically connected with the first end of the relay coil; and a DC power supply electrically connected to the second end of the relay coil.
In some embodiments, the relay drive circuit further comprises: a third capacitor connected in parallel with the relay coil; and the micro control unit is electrically connected with the relay control chip.
In some embodiments, the relay is a relay of an air conditioner controller.
This is disclosed through increasing protection circuit, can absorb the induced electromotive force that the load produced when the relay is turn-off, receives the impact of induced electromotive force to lead to the contact to damage when having avoided the relay to effectively protect the contact of relay, promote the reliability and the security of relay.
Other features of the present disclosure and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.
Drawings
In order to more clearly illustrate the embodiments of the present disclosure or technical solutions in the related art, the drawings required to be used in the description of the embodiments or the related art will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and for those skilled in the art, other drawings may be obtained according to the drawings without inventive exercise.
Fig. 1 shows a schematic diagram of controlling a power supply to power a load using a relay.
Fig. 2 shows a circuit schematic of some embodiments of the disclosed electronic circuit.
Fig. 3 illustrates a circuit schematic of some embodiments of a guard circuit in an electronic circuit.
Detailed Description
The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.
Fig. 1 shows a schematic diagram of controlling a power supply to power a load using a relay. The relay in fig. 1 uses passive contacts, L represents live wire, N represents neutral wire, and DO represents the connection line between load and relay.
The inventor researches and discovers that when a relay with passive contacts is used for controlling a power supply to supply power to a load, if an inductive device exists in the load, the load can generate reverse induced electromotive force when the relay is opened, so that the reverse induced electromotive force is applied to two ends of the passive contacts of the relay and causes impact. When this back electromotive force is larger than a withstand voltage value between the passive contacts of the relay, an arc is generated between the passive contacts of the relay due to a high overvoltage. Once the number of times of opening the relay is too many, the passive contact of the relay will be burnt, thereby causing the relay to be damaged and reducing the reliability of the relay.
In view of the above, the present disclosure provides an electronic circuit capable of improving reliability of a relay. Some embodiments of the disclosed electronic circuit are described below in conjunction with fig. 2.
Fig. 2 shows a circuit schematic of some embodiments of the disclosed electronic circuit. As shown in fig. 2, the electronic circuit includes a power supply circuit 21 and a protection circuit 22. The power supply circuit 21 comprises a power supply 211, a load 212 and a relay 213, wherein the power supply 211 supplies power to the load 212 when the relay 213 is closed; the protection circuit 22 is connected in parallel with the load 212, and the protection circuit 22 forms a loop with the load 212 in a state where the relay 213 is opened.
This embodiment is through increasing protection circuit, can absorb the induced electromotive force that the load produced when the relay is turn-off, and the impact that receives induced electromotive force when having avoided the relay to turn off leads to the contact to damage to effectively protect the contact of relay, promote the reliability and the security of relay.
In addition, this embodiment still has the characteristics that the structure is brief, the practicality is strong, is fit for using in the scene that requires higher to relay reliability.
The protection circuit is described in detail below with reference to fig. 3. Fig. 3 illustrates a circuit schematic of some embodiments of a guard circuit in an electronic circuit. The setting of the protection circuit may specifically include three cases.
(one) first case: only a dc protection circuit is provided.
If the load 212 is a dc load and the power source 211 is a dc power source, the protection circuit 22 includes a voltage dependent resistor RV or a bidirectional TVS (Transient voltage suppression diode). For example, the protection circuit 22 may be a voltage dependent resistor RV, a bidirectional TVS, or a circuit formed by connecting a voltage dependent resistor RV and a bidirectional TVS in series.
In the first case, when the relay 213 is turned off, the dc induced electromotive force generated by the dc load forms a dc load loop through the RV or the bidirectional TVS, and consumes the power on the protection circuit 22, thereby protecting the safety of the relay contacts and improving the reliability of the relay.
(II) second case: only an alternating current protection circuit is provided.
If the load 212 is an ac load and the power source 211 is an ac power source, the protection circuit 22 includes a resistor R1 and a second capacitor C1 connected in series.
In the second case, when the relay 213 is opened, the ac induced electromotive force generated by the ac load forms an ac load loop through DO, R1, and C1, and consumes the power to the protection circuit 22, thereby protecting the safety of the relay contacts and improving the reliability of the relay.
(III) third case: the direct current protection circuit and the alternating current protection circuit are multiplexed, and the direct current protection circuit and the alternating current protection circuit are arranged.
The protection circuit 22 includes a dc protection circuit 221 and an ac protection circuit 222. When the load 212 is a dc load and the power source is a dc power source, the dc protection circuit 221 is turned on to form a dc load loop, and the ac protection circuit 222 is turned off; when the load 212 is an ac load and the power supply 211 is an ac power supply, the ac protection circuit 222 is turned on to form an ac load circuit, and the dc protection circuit 221 is turned off.
In some embodiments, the guard circuit 22 also includes a load detection element 223 and a gating circuit 224. The load detection element 223 is configured to: the dc point characteristic and the ac characteristic of the load 212 are identified to detect whether the load 212 is a dc load or an ac load. When the load 212 is detected to be a direct current load, the control gating circuit switches on the direct current protection circuit 221 and switches off the alternating current protection circuit 222; when the load 212 is detected to be an ac load, the control gate turns on the ac protection circuit 222 and turns off the dc protection circuit 221. Those skilled in the art will appreciate that the dc protection circuit 221 may include a voltage dependent resistor or a bidirectional transient voltage suppression diode, and the ac protection circuit 222 may include a resistor R1 and a second capacitor C1 connected in series.
In some embodiments, the gating circuit may specifically include a single pole double throw switch, and the load detection element may include an inductor and a first capacitor. According to the characteristics of the inductance, the direct current, the resistance and the direct current of the capacitance, under the condition that the inductance is detected to form a channel, the load 212 is determined to be a direct current load, and the direct current protection circuit 221 is gated; in the event that the first capacitance is detected to form a path, the load 212 is determined to be an ac load, and the ac protection circuit 222 is gated on.
The inventor considers that the traditional relay protection circuit is poor in universality, and when the type of a load changes, the protection circuit needs to be changed, involved in experimental verification, so that the development period is long, the development process is complex, and a large amount of manpower and material resources are consumed. In a third case, the electronic circuit multiplexes the protection circuit for absorbing the dc load back emf and the protection circuit for absorbing the ac load back emf simultaneously, enabling flexible switching as required. When the load is switched, the load detection module firstly identifies the load and then gates the corresponding protection circuit, so that the relay is protected. Therefore, the electronic circuit provided by the embodiment can be suitable for different types of loads and has good universality. Therefore, the electronic circuit provided by the embodiment can also reduce the development flow and the development period in practical application, and save the cost of electronic devices.
In some embodiments, the electronic circuit further comprises a relay drive circuit 23. The relay drive circuit 23 includes: a relay coil 231 configured to drive the relay 213 to be closed or opened by the generated electromagnetic force; a relay control chip 232 electrically connected to a first end of the relay coil 231, configured to control the closing or opening of the relay 213; a dc power supply 233, which is electrically connected to a second end of the relay coil 231, is configured to supply power to the relay coil 231.
The control signal output from the relay control chip 232 causes a potential difference to be generated across the relay coil 231 and forms a current loop, thereby generating an electromagnetic force. Under the action of electromagnetic force and the inherent elasticity of the relay reed, the passive contact of the relay 213 is attracted or released, so as to connect or disconnect the loop formed by the load and the power supply.
In some embodiments, the relay drive circuit 23 further includes: a third capacitor 234 connected in parallel with the relay coil 231, configured to isolate the dc power supply 233 from the relay control chip 232; and a micro control unit 235 electrically connected to the relay control chip 232 and configured to control the relay control chip 232.
In some embodiments, the relay 213 is a relay of an air conditioner controller. Those skilled in the art will appreciate that the relay 213 may also be a relay for other electrical devices, and the electronic circuit provided in the above embodiments may also be used to protect relays in other electrical devices so as to absorb the back emf generated by the inductive load in the circuit.
The above description is only exemplary of the present disclosure and is not intended to limit the present disclosure, so that any modification, equivalent replacement, or improvement made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.

Claims (10)

1. An electronic circuit comprising a power supply circuit and a protection circuit; wherein,
the power supply circuit comprises a power supply, a load and a relay, wherein the power supply supplies power to the load under the condition that the relay is closed;
the protection circuit is connected with the load in parallel, and forms a loop with the load under the condition that the relay is disconnected.
2. The electronic circuit of claim 1, wherein the protection circuit comprises a direct current protection circuit and an alternating current protection circuit;
under the condition that the load is a direct-current load and the power supply is a direct-current power supply, the direct-current protection circuit is switched on, and the alternating-current protection circuit is switched off;
and under the condition that the load is an alternating current load and the power supply is an alternating current power supply, the alternating current protection circuit is switched on, and the direct current protection circuit is switched off.
3. The electronic circuit of claim 2, wherein the protection circuit further comprises a load detection element and a gating circuit, the load detection element configured to:
detecting whether the load is a direct current load or an alternating current load;
under the condition that the load is detected to be a direct current load, controlling the gating circuit to switch on the direct current protection circuit and switch off the alternating current protection circuit;
and under the condition that the load is detected to be an alternating current load, controlling the gating circuit to switch on the alternating current protection circuit and switch off the direct current protection circuit.
4. The electronic circuit of claim 3, wherein the load detection element comprises an inductance and a first capacitance configured to:
under the condition that the inductor is detected to form a path, determining that the load is a direct current load;
determining that the load is an alternating current load if it is detected that the first capacitance forms a path.
5. The electronic circuit of claim 2, wherein the dc protection circuit comprises a voltage dependent resistor or a bidirectional transient voltage suppression diode, and the ac protection circuit comprises a resistor and a second capacitor connected in series.
6. The electronic circuit of claim 1, wherein the load is a dc load, the power supply is a dc power supply, and the protection circuit comprises a varistor or a bi-directional transient voltage suppression diode.
7. The electronic circuit of claim 1, wherein the load is an ac load, the power source is an ac power source, and the protection circuit comprises a resistor and a second capacitor connected in series.
8. The electronic circuit of any of claims 1-7, further comprising a relay drive circuit; the relay drive circuit includes:
a relay coil configured to drive the relay to be closed or opened by the generated electromagnetic force;
the relay control chip is electrically connected with the first end of the relay coil;
and a DC power supply electrically connected to the second end of the relay coil.
9. The electronic circuit of claim 8, wherein the relay drive circuit further comprises:
a third capacitor connected in parallel with the relay coil;
and the micro control unit is electrically connected with the relay control chip.
10. The electronic circuit of any of claims 1-9, wherein the relay is a relay of an air conditioner controller.
CN202010997415.6A 2020-09-21 2020-09-21 Electronic circuit Pending CN112071699A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010997415.6A CN112071699A (en) 2020-09-21 2020-09-21 Electronic circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010997415.6A CN112071699A (en) 2020-09-21 2020-09-21 Electronic circuit

Publications (1)

Publication Number Publication Date
CN112071699A true CN112071699A (en) 2020-12-11

Family

ID=73681843

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010997415.6A Pending CN112071699A (en) 2020-09-21 2020-09-21 Electronic circuit

Country Status (1)

Country Link
CN (1) CN112071699A (en)

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