CN113777483B - Relay detection circuit, detection system, power distribution unit and vehicle - Google Patents
Relay detection circuit, detection system, power distribution unit and vehicle Download PDFInfo
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- CN113777483B CN113777483B CN202111131550.3A CN202111131550A CN113777483B CN 113777483 B CN113777483 B CN 113777483B CN 202111131550 A CN202111131550 A CN 202111131550A CN 113777483 B CN113777483 B CN 113777483B
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
- G01R31/3277—Testing of circuit interrupters, switches or circuit-breakers of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
- G01R31/3278—Testing of circuit interrupters, switches or circuit-breakers of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches of relays, solenoids or reed switches
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Abstract
The application relates to a relay detection circuit, a detection system, a power distribution unit and a vehicle, and belongs to the technical field of circuits. Wherein, a relay detection circuitry includes: the device comprises a sampling unit, a driving unit, an isolation unit and a conversion output unit; the sampling unit is used for collecting the first voltage of the contact and outputting a second voltage; the driving unit is used for driving the isolation unit under the action of the second voltage; the isolation unit is used for electrically isolating the driving unit from the conversion output unit; the conversion output unit is used for converting an analog signal input by the output end of the isolation unit into a digital signal and outputting the digital signal, the digital signal is used as a detection signal of the relay detection circuit, and the detection signal is used for the microprocessor to determine the state of the contact. The technical problem of safely and reliably extracting the relay adhesion detection signal is solved, and potential safety hazards in the process of extracting the detection signal are eliminated.
Description
Technical Field
The application relates to the technical field of circuits, in particular to a relay detection circuit, a detection system, a power distribution unit and a vehicle.
Background
With the concept of low-carbon travel, the automobile is developed rapidly. Logic Control units with a Vehicle Controller Unit (VCU) as a core and Control units with a main drive, a Power Distribution Unit (PDU), an Auxiliary Control Module (ACM), a DC/DC switching Power supply, and the like as actuators have also been rapidly developed.
The PDU plays a role in power distribution and power-on time sequence control in the system. Under the cooperation of the relay, the PDU realizes the time-sharing electrification of the control units. The main relay among the PDU keeps the closure state throughout the whole process of new energy automobile operation, and the electric current that flows through this relay can reach hundreds of amperes, and this makes this main relay appear gluing the condition easily, promptly, when needs relay disconnection, the relay can not break off. The situation of surge current may exist at the next power-on, and a large potential safety hazard exists. Therefore, it is necessary to detect whether the relay contacts are stuck or not in the controller and to give an appropriate alarm signal.
The existing PDU relay adhesion detection circuit acquires the voltage of the relay terminal to the ground through a voltage sampling circuit, so that whether the relay contact is adhered or not is determined. In the detection scheme, one end of the voltage sampling circuit is connected with a main loop of hundreds of amperes of current, an analog quantity isolation optocoupler is needed to be used for high-voltage side and low-voltage side electrical isolation, and the detection scheme has potential safety hazards, is complex to implement and has high cost.
Disclosure of Invention
In order to solve the technical problem of extracting the relay adhesion detection signal safely and reliably, the application provides a relay detection circuit, a detection system, a power distribution unit and a vehicle.
In a first aspect, the present application provides a relay detection circuit, comprising: the device comprises a sampling unit, a driving unit, an isolation unit and a conversion output unit;
the input end of the sampling unit is connected with a contact on the load side of the relay, and the output end of the sampling unit is connected with the input end of the driving unit; the sampling unit is used for collecting a first voltage of the contact and outputting a second voltage to the driving unit under the action of the first voltage;
the output end of the driving unit is connected with the input end of the isolation unit; the driving unit is used for driving the isolation unit under the action of the second voltage;
the output end of the isolation unit is connected with the input end of the conversion output unit; the isolation unit is used for electrically isolating the driving unit from the conversion output unit; the output end of the isolation unit is used for controlling the output signal of the conversion output unit;
the output end of the conversion output unit is connected with the microprocessor; the conversion output unit is used for converting an analog signal input by the output end of the isolation unit into a digital signal and outputting the digital signal, the digital signal is used as a detection signal of the relay detection circuit, and the detection signal is used for the microprocessor to determine the state of the contact;
further, the sampling unit includes: the sampling sub-unit, the first resistor and the voltage stabilizing diode; the sampling subunit comprises at least one resistor;
the first end of the sampling subunit is used as the input end of the sampling unit and is connected with the contact, and the second end of the sampling subunit is connected with the first end of the first resistor and the cathode of the voltage stabilizing diode; the second end of the first resistor is grounded; the anode of the voltage stabilizing diode is used as the output end of the sampling unit and is connected with the input end of the driving unit;
further, the sampling sub-unit includes: the second resistor, the third resistor, the fourth resistor, the fifth resistor and the sixth resistor;
a first end of the second resistor is used as an input end of the sampling unit and connected with the contact, a second end of the second resistor is connected with a first end of the third resistor, a second end of the third resistor is connected with a first end of the fourth resistor, a second end of the fourth resistor is connected with a first end of the fifth resistor, a second end of the fifth resistor is connected with a first end of the sixth resistor, and a second end of the sixth resistor is connected with a first end of the first resistor and a cathode of the zener diode;
further, the driving unit includes: the fourth resistor is connected with the fourth resistor;
a first end of the seventh resistor is used as an input end of the driving unit and connected with an output end of the sampling unit, a second end of the seventh resistor is connected with a first end of the eighth resistor and a base electrode of the first triode, a second end of the eighth resistor is grounded, an emitter electrode of the first triode is grounded, a collector electrode of the first triode is connected with a first end of the ninth resistor, the collector electrode of the first triode and a first end of the ninth resistor are used as output ends of the driving circuit, and a second end of the ninth resistor is connected with a first power supply;
further, the isolation unit includes: a tenth resistor, an eleventh resistor, and a photocoupler;
a first end of the tenth resistor is connected with a first input end of the photoelectric coupler, the first end of the tenth resistor and the first input end of the photoelectric coupler are used as input ends of the isolation unit and are connected with an output end of the driving unit, a second end of the tenth resistor is grounded and is connected with a second input end of the photoelectric coupler, the first output end of the photoelectric coupler is connected with a first end of the eleventh resistor, the first output end of the photoelectric coupler and the first end of the eleventh resistor are used as output ends of the isolation unit, the second end of the eleventh resistor is connected with a second power supply, and the second output end of the photoelectric coupler is grounded;
further, the conversion output unit includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a second triode;
a first end of the twelfth resistor is used as an input end of the conversion output unit and connected to an output end of the isolation unit, a second end of the twelfth resistor is connected to a first end of the thirteenth resistor and a base of the second triode, a second end of the thirteenth resistor is grounded and connected to an emitter of the second triode, a collector of the second triode is connected to a first end of the fourteenth resistor, a collector of the second triode and a first end of the fourteenth resistor are used as output ends of the conversion output unit, and a second end of the fourteenth resistor is connected to a second power supply;
further, the driving unit includes: a fifteenth resistor; and a first end of the fifteenth resistor is used as an input end of the driving unit and connected with an output end of the sampling unit, and a second end of the fifteenth resistor is used as an output end of the driving unit and connected with an input end of the isolating unit.
In a second aspect, the present application provides a detection system comprising a relay, a microprocessor and the relay detection circuit of any of the first aspects;
the input end of the relay detection circuit is electrically connected with a contact on the load side of the relay and is used for collecting a first voltage of the contact; the relay detection circuit is used for converting the first voltage into a detection signal, and the detection signal is a digital signal; the output end of the relay detection circuit is connected with the microprocessor and used for outputting the detection signal;
the microprocessor is used for determining the state of the contact according to the detection signal.
In a third aspect, the present application provides a power distribution unit comprising the detection system of the second aspect.
In a fourth aspect, the present application provides a vehicle comprising the detection system of the second aspect.
Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:
this relay detection circuitry that this application embodiment provided includes: the device comprises a sampling unit, a driving unit, an isolation unit and a conversion output unit; the input end of the sampling unit is connected with a contact on the load side of the relay, and the sampling unit is used for collecting a first voltage of the contact and outputting a second voltage to the driving unit under the action of the first voltage; the output end of the sampling unit is connected with the input end of the driving unit; the output end of the driving unit is connected with the input end of the isolation unit; the driving unit is used for driving the isolation unit under the action of the second voltage; the output end of the isolation unit is connected with the input end of the conversion output unit; the isolation unit is used for electrically isolating the driving unit from the conversion output unit; the output end of the isolation unit is used for controlling the output signal of the conversion output unit; the output end of the conversion output unit is connected with the microprocessor; the conversion output unit is used for converting an analog signal input by the output end of the isolation unit into a digital signal and outputting the digital signal, the digital signal is used as a detection signal of the relay detection circuit, and the detection signal is used for the microprocessor to determine the state of the contact. The relay detection circuit is electrically isolated through the isolation unit, the sampled analog voltage signal is converted into a digital signal through the conversion output unit, the digital signal is used as a detection signal, the technical problem that the relay is adhered to the detection signal safely and reliably is solved, and potential safety hazards in the process of extracting the detection signal are eliminated.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.
Fig. 1 is a schematic structural diagram of a relay detection circuit according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of another relay detection circuit provided in the embodiment of the present application;
fig. 3 is a schematic structural diagram of another relay detection circuit provided in the embodiment of the present application;
fig. 4 is a schematic structural diagram of another relay detection circuit provided in the embodiment of the present application;
FIG. 5 is a schematic structural diagram of another relay detection circuit provided in the embodiment of the present application;
fig. 6 is a schematic structural diagram of another relay detection circuit provided in the embodiment of the present application;
fig. 7 is a schematic structural diagram of another relay detection circuit provided in the embodiment of the present application;
fig. 8 is a schematic structural diagram of a detection system according to an embodiment of the present application.
The reference numbers are as follows:
101-a sampling unit; 102-a drive unit; 103-an isolation unit; 104-a conversion output unit; 201-a sampling subunit; r1 — first resistance; d1-zener diode; r2 — second resistance; r3 — third resistance; r4 — fourth resistance; r5-fifth resistor; r6-sixth resistance; r7 — seventh resistor; r8 — eighth resistance; r9 — ninth resistor; q1 — first triode; r10 — tenth resistance; r11 — eleventh resistance; OC 1-opto coupler; r12 — twelfth resistor; r13 — thirteenth resistor; r14-fourteenth resistance; q2-second transistor; r15-fifteenth resistance; 801-a relay; 802-relay detection circuit; 803-microprocessor.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The first embodiment of the present application provides a relay detection circuit, as shown in fig. 1, a sampling unit 101, a driving unit 102, an isolation unit 103, and a conversion output unit 104.
The input end of the sampling unit 101 is connected with a contact on the load side of the relay, and the output end of the sampling unit 101 is connected with the input end of the driving unit 102; the sampling unit 101 is configured to collect a first voltage of the contact, and output a second voltage to the driving unit 102 under the action of the first voltage.
The output end of the driving unit 102 is connected with the input end of the isolation unit 103; the driving unit 102 is used for driving the isolation unit 103 under the action of the second voltage.
The output end of the isolation unit 103 is connected with the input end of the conversion output unit 104; the isolation unit 103 is used for electrically isolating the driving unit 102 from the conversion output unit 104; the output end of the isolation unit 103 is used for controlling the output signal of the conversion output unit 104.
The output end of the conversion output unit 104 is connected with the microprocessor; the conversion output unit 104 is configured to convert an analog signal input from the output terminal of the isolation unit 103 into a digital signal, and output the digital signal, where the digital signal is used as a detection signal of the relay detection circuit, and the detection signal is used by the microprocessor to determine the state of the contact. The conversion process can be realized by a circuit, the digital signal is a signal of a switching value, can be a pulse signal, specifically can be a square wave signal and the like, and the pulse signal or the square wave signal is used as a detection signal of the relay detection circuit.
The contacts of the relay are normally open contacts and normally closed contacts, the contacts in an open state under the normal state (non-electrified) condition are called the normally open contacts, and when the coil is electrified, the normally open contacts are closed. The contact in a closed state under a normal state (non-electrified state) is called a normally closed contact, and when the coil is electrified, the normally closed contact is disconnected. When the contacts should be open but not open, and remain closed, the contacts, referred to as relays, are in a stuck state. It should be noted that the state in which the corresponding relay contact is closed or opened when the square wave signal outputs the signal representing "1" differs depending on the wiring in the detection circuit.
In this embodiment, carry out electrical isolation through isolation unit 103, convert the analog voltage signal who samples into digital signal through conversion output unit 104, regard digital signal as detected signal, solved safe and reliable and extracted the technical problem that relay glues even detected signal, eliminated the potential safety hazard of extracting the detected signal in-process.
In one embodiment, as shown in fig. 2, the sampling unit 101 includes: the sampling sub-unit 201, the first resistor R1 and the zener diode D1, the sampling sub-unit 201 includes at least one resistor.
The connection relationship is as follows: the first end of the sampling sub-unit 201 is used as the input end connection contact of the sampling unit 101, and the second end of the sampling sub-unit 201 is connected with the first end of the first resistor R1 and the cathode of the zener diode D1; the second end of the first resistor R1 is grounded; the anode of the zener diode D1 is connected as the output terminal of the sampling unit 101 to the input terminal of the driving unit 102.
In this embodiment, the sampling subunit 201 divides the voltage of the first voltage of the collected contact, the voltage of the main loop can reach several hundred volts during operation, the sampling subunit 201 divides the voltage of the main loop to improve the safety of the detection circuit, the sampling subunit 201 and the resistance of the first resistor R1 can be reasonably set, the voltage value after division is adjusted, the voltage value after division is divided, the output of the second voltage is controlled by connecting a zener diode D1 in series, the voltage after sampling is higher than the threshold of the breakover voltage of the zener diode D1 to output the second voltage as the breakover voltage, the second voltage lower than the threshold output is zero, namely, the voltage is not conducted. Wherein VCC3 in the circuit represents a power supply in the main loop, S1 represents a set of contacts controlled by the coil in the relay, the first end of the sampling sub-unit 201 is electrically connected to the contact on the load side of S1, and the load in the main loop is equivalent by a resistor.
A Zener diode, also known by the english name Zener diode. The diode with the function of voltage stabilization is manufactured by utilizing the phenomenon that the current of the PN junction can change in a large range and the voltage is basically unchanged in the reverse breakdown state. The diode is a semiconductor device having a high resistance up to a critical reverse breakdown voltage. At the critical breakdown point, the reverse resistance is reduced to a small value, the current is increased in the low-resistance region, the voltage is kept constant, and the voltage regulator diodes are graded according to the breakdown voltage, so that the voltage regulator tubes are mainly used as voltage regulators or voltage reference elements due to the characteristic. The zener diodes can be connected in series for use at higher voltages, with higher regulated voltages being obtained by the series connection.
In the present embodiment, when the relay contact is closed, the voltage at the cathode of the zener diode D1 rises, and when the voltage is lower than the breakdown voltage of the zener diode D1, the zener diode D1 is in the off state, and the back-end circuit does not operate. The sampling unit has the advantages that the voltage stabilizing diode is used for setting the conduction voltage threshold, so that the situation that the circuit is mistakenly conducted due to the fact that the detection circuit is influenced by strong electric interference signals, and the output logic signals of the circuit are disordered can be avoided. The interference can be eliminated, and the detection signal of the relay contact can be accurately acquired.
In one embodiment, as shown in fig. 3, the sampling sub-unit 201 includes: a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6.
The connection relationship is as follows: the first end of the second resistor R2 is used as the input end connection contact of the sampling unit 101, the second end of the second resistor R2 is connected with the first end of the third resistor R3, the second end of the third resistor R3 is connected with the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected with the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected with the first end of the sixth resistor R6, and the second end of the sixth resistor R6 is connected with the first end of the first resistor R1 and the cathode of the zener diode D1.
In this embodiment, the sampling subunit 201 includes five resistors, divide voltage through these five resistors and the combined action of first resistor R1, the resistance can be adjusted as required, the first voltage of several hundred volts of major loop that will gather in contact department passes through the partial voltage, the second voltage value of its output is controlled, for example, when the turn-on threshold voltage of zener diode D1 for selecting for use is 15V, the reasonable selection sampling subunit 201 and the resistance of first resistor R1, it can slightly be higher than 15V to control the voltage value after the partial voltage. Thus, the safety in the process of extracting the detection signal can be obviously improved. When the relay contact is stuck, the divided voltage breaks down the zener diode D1, and a stable 15V voltage is output at the anode of the zener diode D1.
In one embodiment, as shown in fig. 4, the driving unit 102 includes: a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a first triode Q1.
The connection relationship is as follows: a first end of the seventh resistor R7 is used as an input end of the driving unit 102 and connected to an output end of the sampling unit 101, a second end of the seventh resistor R7 is connected to a first end of the eighth resistor R8 and a base of the first triode Q1, a second end of the eighth resistor R8 is grounded, an emitter of the first triode Q1 is grounded, a collector of the first triode Q1 is connected to a first end of the ninth resistor R9, a collector of the first triode Q1 and a first end of the ninth resistor R9 are used as output ends of the driving circuit, and a second end of the ninth resistor R9 is connected to the first power supply.
In this embodiment, for example, the conduction threshold voltage of the zener diode D1 in the sampling unit 101 is 15V, when the relay contact is closed, the voltage of the first voltage divided by the sampling unit 101 is greater than the conduction threshold voltage of the zener diode D1, the voltage output from the zener diode D1 to the driving unit 102 is 15V, the voltage is divided by the seventh resistor R7 and the eighth resistor R8 and flows into the base of the first transistor Q1, so that the first transistor Q1 operates, after the first transistor Q1 operates, the collector and the emitter are turned on, and since the emitter is grounded, the voltage at the first end of the ninth resistor R9 (i.e., the output end of the driving circuit) is pulled down to 0V. When the relay contact is opened, the collected first voltage is 0, the second voltage output by the sampling unit 101 is also 0V, the first triode Q1 does not work, and when the first power supply is 5V, the output end of the driving unit 102 (the first end of the ninth resistor R9) outputs voltage under the action of the first power supply, and the output voltage can drive the light emitting diode at the input side of the photoelectric coupler OC1 of the isolation unit 103 to emit light.
In one embodiment, as shown in fig. 5, the isolation unit 103 includes: a tenth resistor R10, an eleventh resistor R11 and an opto-coupler OC 1.
The connection relationship is as follows: a first end of the tenth resistor R10 is connected to a first input end of the opto-coupler OC1, a first end of the tenth resistor R10 and a first input end of the opto-coupler OC1 are used as input ends of the isolation unit 103 to be connected to an output end of the driving unit 102, a second end of the tenth resistor R10 is grounded and connected to a second input end of the opto-coupler OC1, a first output end of the opto-coupler OC1 is connected to a first end of the eleventh resistor R11, a first output end of the opto-coupler OC1 and a first end of the eleventh resistor R11 are used as output ends of the isolation unit 103, a second end of the eleventh resistor R11 is connected to a second power supply, and a second output end of the opto-coupler OC1 is grounded.
Use optoelectronic coupler, can carry out the electric isolation with the major loop with the detection output, improve the security and the interference killing feature that detect the output to, compare the simulation opto-coupler, use optoelectronic coupler can practice thrift the cost. And the reasonable type selection of the optical coupler can meet the safety requirements of circuit design.
When the driving unit 102 includes the seventh resistor R7, the eighth resistor R8, the ninth resistor R9 and the first transistor Q1, when the relay contact is closed, the voltage of the first voltage divided by the sampling unit 101 is greater than the conduction threshold voltage of the zener diode D1, the voltage output by the zener diode D1 to the driving unit 102 is 15V, and after the voltage is divided by the seventh resistor R7 and the eighth resistor R8, flows into the base of the first triode Q1 to make the first triode Q1 work, after the first triode Q1 works, the collector and the emitter are conducted, since the emitter is grounded, the voltage at the first terminal of the ninth resistor R9 (i.e. the output terminal of the driving circuit) is pulled down to 0V, that is, the first input terminal of the photocoupler OC1 of the isolation unit 103 inputs 0V, and the photocoupler OC1 does not work, for example, when the second power supply is 5V, the output terminal of the isolation unit 103 (the first terminal of the eleventh resistor R11) outputs a voltage under the action of the second power supply. When the relay contact is disconnected, the collected first voltage is 0V, the second voltage output by the sampling unit 101 is also 0V, the first triode Q1 does not work, the output end of the driving unit 102 (the first end of the ninth resistor R9) outputs voltage to the first input end of the photoelectric coupler OC1 after being subjected to voltage division through the ninth resistor R9 and the tenth resistor R10 under the action of the first power supply, the light emitting diode is driven to emit light, the equivalent triode inside the photoelectric coupler OC1 works, the collector electrode is also pulled down to 0V due to the grounding of the emitter electrode of the triode, and the output voltage of the isolating unit 103 is 0V.
In one embodiment, as shown in fig. 6, the conversion output unit 104 includes: a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14 and a second triode Q2.
The connection relationship is as follows: a first end of the twelfth resistor R12 is connected to the output end of the isolation unit 103 as the input end of the switching output unit 104, a second end of the twelfth resistor R12 is connected to the first end of the thirteenth resistor R13 and the base of the second transistor Q2, a second end of the thirteenth resistor R13 is grounded and connected to the emitter of the second transistor Q2, a collector of the second transistor Q2 is connected to the first end of the fourteenth resistor R14, a collector of the second transistor Q2 and the first end of the fourteenth resistor R14 are used as the output end of the switching output unit 104, and a second end of the fourteenth resistor R14 is connected to the second power supply.
In this embodiment, it is exemplified that the driving unit 102 includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a first transistor Q1, and the isolation unit 103 includes a tenth resistor R10, an eleventh resistor R11, and a photo-coupler OC 1. When the relay contact is closed, the intermediate process is not described in detail, and the output end of the isolation unit 103 (the first end of the eleventh resistor R11) outputs voltage under the action of the second power supply. This voltage may cause the second transistor Q2 to operate, and the collector and the emitter of the second transistor Q2 are turned on, and since the emitter is grounded, the collector is pulled down to 0V, so that the detection signal output by the switching output unit 104 is "0". When the relay contact is closed, the intermediate process is not described again, the output voltage of the output end of the isolation unit 103 is 0V, the second triode Q2 does not work, and the output end of the conversion output unit 104 outputs "1" under the action of the second power supply.
When the light emitting diode in the photoelectric coupler OC1 emits light, the circuit state is recorded as circuit state A, when the light emitting diode in the photoelectric coupler OC1 is extinguished, the circuit state is recorded as circuit state B, the circuit state is detected once before and after the controller disconnects the main loop, if the circuit state is switched from state B to state A, the condition that the relay is not adhered is indicated, if the circuit state is always state B, the condition that the relay is adhered is indicated, and at the moment, the microprocessor sends an alarm signal to indicate that the contact of the relay is adhered.
The detection circuit converts the analog high-voltage signal into a switching value signal of a TTL level, and a detection signal at the output end of the conversion output unit 104 can be directly output to the microprocessor for logic processing. The TTL level signal specifies that +5V is equivalent to a logic "1" and 0V is equivalent to a logic "0". Such a data communication and level regulation system is called a TTL (transistor-transistor logic level) signaling system. It should be noted that the microprocessor herein refers to a device having a processor function, and may be a Digital Signal Processor (DSP) or a Micro Controller Unit (MCU), or may be a processor in a general sense if cost is not considered.
In addition, the second power supply may be 5V, the first power supply may also be 5V, and the second power supply and the first power supply may be respectively supplied with power by the power supply, or the second power supply may supply power to the first power supply through the isolation power supply. However, since the first power source is on the input side of the isolation unit 103, i.e. on the high voltage side of the main circuit, the power source supplying power to the first power source must be isolated, which will increase part of the circuit cost virtually. The present application also provides a circuit that does not require a first power supply for ease of use and cost savings.
In one embodiment, as shown in fig. 7, the driving unit 102 includes: a fifteenth resistor R15. The connection relationship is as follows: a first terminal of the fifteenth resistor R15 is connected to the output terminal of the sampling unit 101 as the input terminal of the driving unit 102, and a second terminal of the fifteenth resistor R15 is connected to the input terminal of the isolation unit 103 as the output terminal of the driving unit 102.
In the embodiment, the high-voltage side driving unit is optimized, an additional power supply is not needed, the safety of the circuit is improved, and the cost is saved.
The following description is given by taking the sampling unit 101 as including a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a zener diode D1, the isolation unit 103 as including a tenth resistor R10, an eleventh resistor R11, and a photocoupler OC1, and the conversion output unit 104 as including a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, and a second triode Q2. If the conduction threshold voltage of the selected zener diode D1 is 15V and the second power supply is 5V, when the relay contact is closed, the voltage of the first voltage after being divided by the sampling unit 101 is greater than the conduction threshold voltage of the zener diode D1, the voltage output by the zener diode D1 to the driving unit 102 is 15V, the first voltage is input to the first input end of the photoelectric coupler OC1 of the isolation unit 103 through the fifteenth resistor R15, the light emitting diode of the photoelectric coupler OC1 emits light, the equivalent triode in the photoelectric coupler OC1 works, because the second output end is grounded, the first output end of the photoelectric coupler OC1 is pulled down to 0V, the second triode Q2 does not work, and the output end of the conversion output unit 104 outputs "1" under the action of the second power supply. When the relay contact is disconnected, the collected first voltage is 0V, the second voltage output by the sampling unit 101 is also 0V, the output end of the driving unit 102 is also 0V, the light emitting diode does not emit light, the equivalent triode in the optoelectronic coupler OC1 does not work, the second triode Q2 works under the action of the second power supply, the collector and the emitter are connected, and the collector of the second triode Q2 is pulled down to 0V due to the grounding of the emitter, so that the detection signal output by the conversion output unit 104 is 0.
When the light emitting diode in the photoelectric coupler OC1 emits light, the circuit state is recorded as circuit state A, when the light emitting diode in the photoelectric coupler OC1 is extinguished, the circuit state is recorded as circuit state B, the circuit state is detected once before and after the controller disconnects the main loop, if the circuit state is switched from state A to state B, the condition that the relay is not adhered is indicated, if the circuit state is always state A, the condition that the relay is adhered is indicated, and at the moment, the microprocessor sends an alarm signal to indicate that the contact of the relay is adhered.
In addition, it should be noted that the triode included in each embodiment of the present application may be an NPN type or a PNP type, or may be replaced by another element having a switching function, such as an MOS transistor, and of course, the MOS transistor may be a PMOS transistor or an NMOS transistor.
The second embodiment of the present application provides a detection system, as shown in fig. 8, comprising a relay 801, a microprocessor 803, and a relay detection circuit 802 according to any one of the first embodiment of the present application.
The input end of the relay detection circuit 802 is electrically connected with a contact point on the load side of the relay 801 and is used for collecting a first voltage of the contact point; the relay detection circuit 802 is configured to convert the first voltage into a detection signal, where the detection signal is a digital signal; the output terminal of the relay detection circuit 802 is connected to the microprocessor 803 for outputting the detection signal.
The microprocessor 803 is used to determine the state of the contact point according to the detection signal.
The detection system using the relay detection circuit is electrically isolated through the isolation unit, sampled analog voltage signals are converted into digital signals through the conversion output unit, the digital signals are used as detection signals, the technical problem that the relay adhesion detection signals are extracted safely and reliably is solved, and potential safety hazards in the process of extracting the relay detection signals are eliminated.
A third embodiment of the present application provides a power distribution unit comprising the detection system of the second embodiment. The power distribution unit of the detection system can safely and reliably extract the relay adhesion detection signal, eliminates the potential safety hazard in the process of extracting the relay detection signal, can accurately identify the relay adhesion state, and avoids the damage to the circuit caused by surge current which possibly occurs when the relay in the adhesion state is electrified again.
A fourth embodiment of the present application provides a vehicle including the detection system of the second embodiment. The vehicle using the detection system can safely and reliably extract the relay adhesion detection signal, can accurately identify the relay adhesion state, and avoids the damage to the vehicle caused by surge current which possibly occurs when the relay in the adhesion state is electrified again.
It is noted that, in this document, relational terms such as "first" and "second," and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above description is merely illustrative of particular embodiments of the invention that enable those skilled in the art to understand or practice the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (9)
1. A relay detection circuit, comprising: the device comprises a sampling unit, a driving unit, an isolation unit and a conversion output unit;
the input end of the sampling unit is connected with a contact on the load side of the relay, and the output end of the sampling unit is connected with the input end of the driving unit; the sampling unit is used for collecting a first voltage of the contact and outputting a second voltage to the driving unit under the action of the first voltage;
the output end of the driving unit is connected with the input end of the isolation unit; the driving unit is used for driving the isolation unit under the action of the second voltage;
the output end of the isolation unit is connected with the input end of the conversion output unit; the isolation unit is used for electrically isolating the driving unit from the conversion output unit; the output end of the isolation unit is used for controlling the output signal of the conversion output unit;
the output end of the conversion output unit is connected with the microprocessor; the conversion output unit is used for converting an analog signal input by the output end of the isolation unit into a digital signal and outputting the digital signal, the digital signal is used as a detection signal of the relay detection circuit, and the detection signal is used for the microprocessor to determine the state of the contact;
wherein the sampling unit includes: the sampling sub-unit, the first resistor and the voltage stabilizing diode; the sampling subunit comprises at least one resistor;
the first end of the sampling subunit is used as the input end of the sampling unit and is connected with the contact, and the second end of the sampling subunit is connected with the first end of the first resistor and the cathode of the voltage stabilizing diode; the second end of the first resistor is grounded; and the anode of the voltage stabilizing diode is used as the output end of the sampling unit and is connected with the input end of the driving unit.
2. The relay detection circuit according to claim 1, wherein the sampling subunit comprises: the second resistor, the third resistor, the fourth resistor, the fifth resistor and the sixth resistor;
the first end of the second resistor is used as the input end of the sampling unit and connected with the contact, the second end of the second resistor is connected with the first end of the third resistor, the second end of the third resistor is connected with the first end of the fourth resistor, the second end of the fourth resistor is connected with the first end of the fifth resistor, the second end of the fifth resistor is connected with the first end of the sixth resistor, and the second end of the sixth resistor is connected with the first end of the first resistor and the cathode of the zener diode.
3. The relay detection circuit according to claim 1, wherein the driving unit includes: the fourth resistor is connected with the fourth resistor;
the first end of the seventh resistor is used as the input end of the driving unit to be connected with the output end of the sampling unit, the second end of the seventh resistor is connected with the first end of the eighth resistor and the base electrode of the first triode, the second end of the eighth resistor is grounded, the emitting electrode of the first triode is grounded, the collecting electrode of the first triode is connected with the first end of the ninth resistor, the collecting electrode of the first triode and the first end of the ninth resistor are used as the output end of the driving unit, and the second end of the ninth resistor is connected with the first power supply.
4. The relay detection circuit according to claim 1, wherein the isolation unit comprises: a tenth resistor, an eleventh resistor and a photoelectric coupler;
the first end of the tenth resistor is connected with the first input end of the photoelectric coupler, the first end of the tenth resistor and the first input end of the photoelectric coupler are used as the input end of the isolation unit to be connected with the output end of the driving unit, the second end of the tenth resistor is grounded and connected with the second input end of the photoelectric coupler, the first output end of the photoelectric coupler is connected with the first end of the eleventh resistor, the first output end of the photoelectric coupler and the first end of the eleventh resistor are used as the output end of the isolation unit, the second end of the eleventh resistor is connected with the second power supply, and the second output end of the photoelectric coupler is grounded.
5. The relay detection circuit according to claim 1, wherein the switching output unit includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a second triode;
a first end of the twelfth resistor is used as an input end of the conversion output unit and connected to an output end of the isolation unit, a second end of the twelfth resistor is connected to a first end of the thirteenth resistor and a base of the second triode, a second end of the thirteenth resistor is grounded and connected to an emitter of the second triode, a collector of the second triode is connected to a first end of the fourteenth resistor, a collector of the second triode and a first end of the fourteenth resistor are used as output ends of the conversion output unit, and a second end of the fourteenth resistor is connected to a second power supply.
6. The relay detection circuit according to claim 1, wherein the driving unit includes: a fifteenth resistor; and a first end of the fifteenth resistor is used as an input end of the driving unit and connected with an output end of the sampling unit, and a second end of the fifteenth resistor is used as an output end of the driving unit and connected with an input end of the isolation unit.
7. A test system comprising a relay, a microprocessor and a relay test circuit according to any one of claims 1 to 6;
the input end of the relay detection circuit is electrically connected with a contact point on the load side of the relay and is used for collecting a first voltage of the contact point; the relay detection circuit is used for converting the first voltage into a detection signal, and the detection signal is a digital signal; the output end of the relay detection circuit is connected with the microprocessor and used for outputting the detection signal;
the microprocessor is used for determining the state of the contact according to the detection signal.
8. A power distribution unit comprising the detection system of claim 7.
9. A vehicle comprising the detection system of claim 7.
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| CN202111131550.3A CN113777483B (en) | 2021-09-26 | 2021-09-26 | Relay detection circuit, detection system, power distribution unit and vehicle |
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| CN202111131550.3A CN113777483B (en) | 2021-09-26 | 2021-09-26 | Relay detection circuit, detection system, power distribution unit and vehicle |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103022959B (en) * | 2013-01-11 | 2014-12-24 | 南阳防爆电气研究所有限公司 | Method and device for adhesion detection of main contact of alternating-current contactor |
| CN205880149U (en) * | 2016-06-08 | 2017-01-11 | 武汉合康智能电气有限公司 | Well power relay contact adhesion detection circuitry |
| CN206271619U (en) * | 2016-11-03 | 2017-06-20 | 江苏英索纳智能科技有限公司 | Self-correcting relay anti-adhesion circuit |
| CN208299783U (en) * | 2018-05-10 | 2018-12-28 | 比亚迪股份有限公司 | Digital quantity signal Acquisition Circuit |
| CN109116230B (en) * | 2018-10-26 | 2024-05-03 | 常州是为电子有限公司 | High-voltage relay state on-line monitoring device and method |
| CN209356564U (en) * | 2018-12-25 | 2019-09-06 | 深圳创维汽车智能有限公司 | Voltage acquisition isolation circuit, power-supply system and electrical equipment |
| CN211741505U (en) * | 2019-10-17 | 2020-10-23 | 珠海格力电器股份有限公司 | Relay state detection circuit and device |
| CN112782570A (en) * | 2019-11-06 | 2021-05-11 | 株洲中车时代电气股份有限公司 | System and method for monitoring relay |
| CN111029212A (en) * | 2019-12-26 | 2020-04-17 | 深圳市蓝海华腾技术股份有限公司 | Relay contact state detection circuit, vehicle and high-voltage power distribution system |
| CN111044897A (en) * | 2019-12-27 | 2020-04-21 | 珠海格力电器股份有限公司 | Relay state detection circuit, control method and whole vehicle integrated controller |
| CN112213631B (en) * | 2020-09-03 | 2021-11-09 | 珠海格力电器股份有限公司 | Relay state detection device and method and automobile |
| CN112505534A (en) * | 2020-09-29 | 2021-03-16 | 上海亮一科技有限公司 | Relay adhesion and output short circuit detection circuit |
| CN113156307A (en) * | 2021-04-09 | 2021-07-23 | 深圳市誉娇诚科技有限公司 | Battery system high-voltage relay adhesion fault detection circuit and method |
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