AC input detection circuit, detection method and electronic equipment

Abstract

The present invention relates to an AC input detection circuit, a detection method and an electronic device, comprising: a DC power supply unit, an AC power input terminal including a first input terminal and a second input terminal, a voltage extraction unit connected to the second input terminal, a first switch unit connected to the voltage extraction unit, wherein the first input terminal is used to connect to an AC working circuit, the second input terminal is used to connect to the AC working circuit via the voltage extraction unit, and the voltage extraction unit is used to generate a driving voltage corresponding to the AC input when the first switch unit is turned on; and a control unit connected to the first switch unit; a second switch unit connected to the voltage extraction unit and the first input terminal; a timing unit connected to the second switch unit; a storage unit for storing a corresponding relationship between a preset continuous conduction time length of the conduction of the second switch unit and the AC input voltage; and a processing unit connected to the timing unit and the storage unit. The present invention has a simple process, a small volume and low cost.

Description

Technical Field

[0001] The present invention relates to an AC input detection technology, and more specifically, to an AC input detection circuit, a detection method and an electronic device. Background Art

[0002] In heating equipment such as soybean milk machines and wall breaking machines, the heating process needs to be monitored so that it can work at the required power. The detection process of AC input is usually to detect its input current through a magnetic ring, and finally get the detection of AC input based on the current. Its detection through magnetic ring will lead to a large volume occupied by the detection circuit in the circuit design, and the use of magnetic ring will lead to high detection cost. It is not conducive to the cost reduction requirements of small household appliances. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an AC input detection circuit, a detection method and an electronic device in view of the above-mentioned technical defects of the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: construct an AC input detection circuit, including: a DC power supply unit for providing a DC voltage, an AC power input terminal including a first input terminal and a second input terminal, a voltage extraction unit connected to the second input terminal, and a first switch unit connected to the voltage extraction unit, wherein the first input terminal is used to connect to an AC working circuit, the second input terminal is used to connect to the AC working circuit via the voltage extraction unit, and the voltage extraction unit is used to generate a driving voltage corresponding to the AC input when the first switch unit is turned on; and

[0005] A control unit connected to the first switch unit and configured to output a first switch control level to control the first switch unit to be turned on or off;

[0006] A second switch unit connected to the voltage extraction unit and the first input terminal and configured to receive the driving voltage to switch on or off;

[0007] A timing unit connected to the second switch unit and used to record the actual continuous conduction time of the second switch unit;

[0008] a storage unit for storing a corresponding relationship between a preset continuous conduction time length of the conduction of the second switch unit and an AC input voltage;

[0009] A processing unit connected to the timing unit and the storage unit and configured to obtain the actual continuous conduction time and obtain the corresponding AC input voltage from the storage unit.

[0010] Preferably, the voltage extraction unit comprises a voltage dividing circuit and a first sub-switch;

[0011] The first end of the voltage divider circuit is connected to the second input end, the second end of the voltage divider circuit is connected to the first end of the first sub-switch, the first switch unit and the second switch unit, the second end of the first sub-switch is used to connect to the AC working circuit, and the third end of the first sub-switch is connected to the first switch unit.

[0012] Preferably, the first switch unit includes a second sub-switch and a first isolating switch; a first end of the second sub-switch is connected to the control unit, a second end of the second sub-switch is connected to the DC power supply unit, a third end of the second sub-switch is connected to the second end of the first isolating switch, a first end of the first isolating switch is connected to the DC power supply unit, a third end of the first isolating switch is connected to the third end of the first sub-switch, and a fourth end of the first isolating switch is connected to the second end of the voltage divider circuit; and / or

[0013] The second switch unit includes a third sub-switch and a second isolating switch; the first end of the third sub-switch is connected to the second input end, the second end of the third sub-switch is connected to the second end of the voltage divider circuit, the third end of the third sub-switch is connected to the first end of the second isolating switch, the second end of the second isolating switch is connected to the second input end, the third end of the second isolating switch is grounded, and the fourth end of the second isolating switch is connected to the timing unit.

[0014] Preferably, the first sub-switch comprises a thyristor switch TR1, the A1 pin of the thyristor switch TR1 is connected to the AC working circuit, the A2 pin of the thyristor switch TR1 is connected to the voltage divider circuit, and the G pin of the thyristor switch TR1 is connected to the first isolation switch; and / or

[0015] The voltage divider circuit includes a resistor R11 and a resistor R12. The resistor R11 and the resistor R12 are connected in parallel, one end of which is connected to the second input end, and the other end of which is connected to the first end of the first sub-switch and the second end of the third sub-switch.

[0016] Preferably, the second sub-switch comprises a transistor Q1 and a resistor R2; the base of the transistor Q1 is connected to the control unit, the base of the transistor Q1 is grounded via the resistor R2, the emitter of the transistor Q1 is grounded, and the collector of the transistor Q1 is connected to the DC power supply unit and the first isolating switch; and / or

[0017] The first isolating switch includes a thyristor isolation chip IC1, a resistor R3, a resistor R4 and a resistor R5. The first pin of the thyristor isolation chip IC1 is connected to the DC power supply unit, the second pin of the thyristor isolation chip IC1 is connected to the collector of the transistor Q1 via the resistor R3, and the sixth pin of the thyristor isolation chip IC1 is connected to the second end of the voltage divider circuit via the resistor R5 and the resistor R4 connected in series.

[0018] Preferably, the third sub-switch includes a MOS transistor Q2, a resistor R6, a resistor R7 and a resistor R10; the gate of the MOS transistor Q2 is connected to the second end of the voltage divider circuit via the resistor R10, the source of the MOS transistor Q2 is connected to the second input end, the drain of the MOS transistor Q2 is connected to the first input end via the resistor R6 and the resistor R7 connected in series, and the drain of the MOS transistor Q2 is connected to the first end of the second isolation switch; and / or

[0019] The second isolating switch includes an optocoupler chip U2, a first pin of the optocoupler chip U2 is connected to the drain of the MOS tube Q2, a second pin of the optocoupler chip U2 is connected to the second input end, a third pin of the optocoupler chip U2 is grounded, and a fourth pin of the optocoupler chip U2 is connected to the timing unit.

[0020] Preferably, the timing unit, the processing unit and the control unit are integrated into a control chip U1.

[0021] Preferably, the first input end is an ACL end of an AC power input, and the second input end is a CAN end of the AC power input.

[0022] In addition, the present invention also constructs an electronic device, including: an AC working circuit and an AC input detection circuit as described in any one of the above.

[0023] In addition, an AC input detection method of the present invention is applied to the AC input detection circuit as described in any one of the above; the process includes:

[0024] S1. Triggering the first switch unit to turn on through a control unit to trigger the voltage extraction unit to generate a driving voltage corresponding to an AC input, wherein the control unit triggers the first switch unit to turn on for a time greater than a half-wave period of the AC input;

[0025] S2, driving the second switch unit to turn on by the driving voltage, and obtaining an actual continuous conduction time length of the second switch unit when the second switch unit is triggered to turn on;

[0026] S3. Obtain a corresponding AC input voltage from the storage unit according to the actual continuous conduction time.

[0027] Preferably, an AC input detection method of the present invention further includes:

[0028] S4, obtaining the number of times the second switch unit is turned on within a preset time and a plurality of actual continuous turn-on time durations corresponding to the number of times;

[0029] S5. Obtain an average continuous conduction time corresponding to the preset time according to the multiple actual continuous conduction time and the number of conduction times, so as to obtain the AC input voltage within the preset time from the storage unit according to the average continuous conduction time.

[0030] The AC input detection circuit, detection method and electronic equipment implemented in the present invention have the following beneficial effects: simple process, small size and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0032] Figure 1 It is a logic block diagram of an AC input detection circuit of the present invention;

[0033] Figure 2 It is a logic block diagram of an embodiment of an AC input detection circuit of the present invention;

[0034] Figure 3 It is a circuit principle diagram of an embodiment of an AC input detection circuit of the present invention;

[0035] Figure 4 It is a schematic diagram of the working principle of an AC input detection circuit of the present invention;

[0036] Figure 5 It is a flow chart of an embodiment of an AC input detection method of the present invention;

[0037] Figure 6 It is a flow chart of another embodiment of an AC input detection method of the present invention. DETAILED DESCRIPTION

[0038] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0039] like Figure 1As shown, in a first embodiment of an AC input detection circuit 100 of the present invention, it includes: a DC power supply unit 110 for providing a DC voltage, an AC power input terminal 120 including a first input terminal 121 and a second input terminal 122, a voltage extraction unit 130 connected to the second input terminal 122, and a first switch unit 140 connected to the voltage extraction unit 130, wherein the first input terminal 121 is used to connect to the AC working circuit 200, the second input terminal 122 is used to connect to the AC working circuit 200 via the voltage extraction unit 130, and the voltage extraction unit 130 is used to generate a driving voltage corresponding to the AC input when the first switch unit 140 is turned on; and a first switch unit 140 connected to the first switch unit 140 and configured A control unit 160 configured to output a first switch control level to control the first switch unit 140 to be turned on or off; a second switch unit 150 connected to the voltage extraction unit 130 and the first input terminal 121, and configured to receive a driving voltage to turn on or off; a timing unit 170 connected to the second switch unit 150 and used to record the actual continuous conduction time of the second switch unit 150; a storage unit 190 for storing the corresponding relationship between the preset continuous conduction time of the second switch unit 150 and the AC input voltage; a processing unit 180 connected to the timing unit 170 and the storage unit 190, and configured to obtain the actual continuous conduction time and obtain the corresponding AC input voltage from the storage unit 190. Specifically, the DC power supply unit is used to provide DC AC input voltages for each functional module of the detection circuit to meet the working needs of each functional module. The AC power input is used to provide AC input for the AC working circuit 200, and the AC power input parameters are set to meet the power parameter requirements of various working states of the AC working circuit 200. The AC power input terminal 120 includes a first input terminal 121 and a second input terminal 122. The first input terminal 121 is directly connected to the AC working circuit 200. The second input terminal 122 is connected to the AC working circuit 200 through the voltage extraction unit 130. The voltage extraction unit 130 is connected to the first switch unit 140. When the first switch unit 140 is turned on, it is turned on to make the second input terminal 122 and the AC working circuit 200 connected. At this time, the first input terminal 121 and the second input terminal 122 form a loop with the AC working circuit 200 to supply power to the AC working circuit 200. At the same time, when the voltage extraction unit 130 is turned on, it generates a driving voltage corresponding to the AC input. It can be understood that the driving voltage corresponds to the working state of the AC working circuit 200. When the voltage extraction unit 130 is powered on, the AC working circuit 200 is powered on. When the AC working circuit 200 is powered on, the voltage extraction unit 130 generates a driving voltage. The first switch unit 140 is connected to the control unit 160, and the control unit 160 outputs a control level to drive the first switch unit 140 to turn on or off. The second switch unit 150 is connected to the voltage extraction unit 130 , and is turned on or off according to the magnitude of the driving voltage after receiving the driving voltage generated by the voltage extraction unit 130 .The timing unit 170 is connected to the second switch unit 150, and is used to record the continuous conduction time when the second switch is turned on. The storage unit 190 stores the corresponding relationship between the preset continuous conduction time of the second switch unit 150 and the AC input voltage; the processing unit 180 is connected to the timing unit 170 and the storage unit 190, and is configured to obtain the actual continuous conduction time and obtain the corresponding AC input voltage from the storage unit 190, that is, after obtaining the measured actual continuous conduction time, the processing unit 180 obtains the corresponding AC input voltage according to the actual continuous conduction time according to the preset continuous conduction time and the AC input voltage stored in the storage unit 190. That is, the specific process is understood as follows: when the AC working circuit 200 is working, its AC input is a sine or cosine voltage, that is, it increases or decreases with time, and the driving voltage generated by the voltage extraction unit 130 is in a corresponding relationship with the AC input, that is, it can be understood that when the AC input increases, the driving voltage generated by the voltage extraction unit 130 is larger, and when the AC input decreases, the driving voltage generated by the voltage extraction unit 130 is smaller. When the driving voltage reaches the conduction threshold of the second switch unit 150, the second switch unit 150 is turned on. When the driving voltage is less than the conduction threshold of the second switch unit 150, the second switch unit 150 is turned off. At this time, the timing unit 170 records the duration of the conduction of the second switch unit 150, that is, the corresponding AC input. As. Figure 4 As shown, V1, V2, and V3 in the AC input current and voltage waveform are different AC inputs, wherein Vth is the on-voltage of the second switch unit 150. Under different AC inputs, the continuous on-time t1, t2, and t3 of the second switch unit 150 are different. The timing unit 170 can obtain the AC input voltage according to the preset relationship between the timing t1, t2, and t3 and V1, V2, and V3.

[0040] like Figure 2 As shown, in one embodiment, the voltage extraction unit 130 includes a voltage divider circuit 131 and a first sub-switch 132; the first end of the voltage divider circuit 131 is connected to the second input end 122, the second end of the voltage divider circuit 131 is connected to the first end of the first sub-switch 132, the first switch unit 140 and the second switch unit 150, the second end of the first sub-switch 132 is used to connect to the AC working circuit 200, and the third end of the first sub-switch 132 is connected to the first switch unit 140. Specifically, the first switch unit 140 is turned on to turn on the first sub-switch 132. When the first sub-switch 132 is turned on, a voltage divider is formed at both ends of the voltage divider circuit 131, and the voltage divider is the driving voltage corresponding to the AC input output of the voltage extraction unit 130. Among them, once the voltage divider circuit 131 is set, the voltage divider value obtained is related to the AC input parameters of the AC working circuit 200 when the AC working circuit 200 is working. For example, when the AC input voltage of the AC working circuit 200 is large, the AC voltage divider formed at both ends of the voltage divider circuit 131 will also be large.

[0041] In one embodiment, the first switch unit 140 includes a second sub-switch 141 and a first isolating switch 142; the first end of the second sub-switch 141 is connected to the control unit 160, the second end of the second sub-switch 141 is connected to the DC power supply unit, the third end of the second sub-switch 141 is connected to the second end of the first isolating switch 142, the first end of the first isolating switch 142 is connected to the DC power supply unit, the third end of the first isolating switch 142 is connected to the third end of the first sub-switch 132, and the fourth end of the first isolating switch 142 is connected to the second end of the voltage divider circuit 131; specifically, the second sub-switch 141 is connected to the control unit 160, and is turned on or off when the control unit 160 outputs a control level, and the first isolating switch 142 is connected to the second sub-switch 141, and is turned on when the second sub-switch 141 is turned on, and is turned off when the second sub-switch 141 is turned off. The first sub-switch 132 is connected to the first isolating switch 142, and is turned on when the first isolating switch 142 is turned on, and is turned off when the first isolating switch 142 is turned off.

[0042] In one embodiment, the second switch unit 150 includes a third sub-switch 151 and a second isolating switch 152; a first end of the third sub-switch 151 is connected to the second input end 122, a second end of the third sub-switch 151 is connected to the second end of the voltage divider circuit 131, a third end of the third sub-switch 151 is connected to the first end of the second isolating switch 152, a second end of the second isolating switch 152 is connected to the second input end 122, a third end of the second isolating switch 152 is grounded, and a fourth end of the second isolating switch 152 is connected to the timing unit 170. Specifically, when the third sub-switch 151 is connected to the voltage divider circuit 131 and there is no voltage division at both ends of the voltage divider circuit 131, the third sub-switch 151 is in an off state, and at this time, a low level is generated at the corresponding pin of the timing unit 170 through the second isolating switch 152. When the AC input increases continuously, the voltage across the voltage divider circuit 131 will gradually increase. In the process of increasing the voltage gradually, the voltage across the voltage divider circuit 131 will increase to meet a certain value, i.e., a preset threshold value, to drive the third sub-switch 151 to turn on. After the third sub-switch 151 is turned on, it generates a high level at the corresponding pin of the timing unit 170 through the second isolation switch 152. When the AC input increases to the maximum value, it will continue to decrease, and the voltage across the voltage divider circuit 131 will gradually decrease. In the process of decreasing the voltage gradually, the voltage across the voltage divider circuit 131 will decrease to less than the preset threshold value, and the third sub-switch 151 is in the off state. At this time, a low level is generated at the corresponding pin of the timing unit 170 through the second isolation switch 152. The timing unit 170 can obtain the continuous conduction time of the third sub-switch 151 according to the duration of the high level of the corresponding pin, which corresponds to the continuous conduction time of the second switch unit 150.

[0043] Optional, such as Figure 3 As shown, the first sub-switch 132 includes a thyristor switch TR1, the A1 pin of the thyristor switch TR1 is connected to the AC working circuit 200, the A2 pin of the thyristor switch TR1 is connected to the voltage divider circuit 131, and the G pin of the thyristor switch TR1 is connected to the first isolation switch 142; specifically, when a positive or negative trigger voltage (i.e. UG>0 or UG<0) is applied to the control electrode (G) of the thyristor switch TR1, the thyristor switch TR1 is turned on regardless of whether a positive voltage or a reverse voltage is applied between the first anode (corresponding to the A1 pin) and the second anode (corresponding to the A2 pin). After the thyristor switch TR1 is turned on, its control electrode (G) will lose its function, i.e.: when UG=0, the thyristor switch TR1 is still turned on. That is, when its control pin, i.e., the G pin, receives the control level, it is turned on so that the input of the AC working circuit 200 forms a loop, and the AC working circuit 200 is powered on and works.

[0044] Optionally, the voltage divider circuit 131 includes a resistor R11 and a resistor R12, and the resistor R11 and the resistor R12 are connected in parallel, and one end of the resistor R11 and the resistor R12 are connected to the second input terminal 122, and the other end is connected to the first end of the first sub-switch 132 and the second end of the third sub-switch 151. Specifically, the parallel resistors R11 and R12 are connected to the AC circuit through the first sub-switch 132 to form a series relationship with the AC working circuit 200. When the AC working circuit 200 is powered on, a voltage is formed at both ends thereof. Here, by selecting appropriate values ​​of the resistor R11 and the resistor R12, the voltage obtained thereby meets the requirements for setting the conduction threshold of the third sub-switch 151.

[0045] Optionally, the second sub-switch 141 includes a transistor Q1 and a resistor R2; the base of the transistor Q1 is connected to the control unit 160, the base of the transistor Q1 is grounded via the resistor R2, the emitter of the transistor Q1 is grounded, and the collector of the transistor Q1 is connected to the DC power supply unit and the first isolating switch 142; specifically, in the second sub-switch 141, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the DC power supply unit, and the base of the transistor Q1 is connected to the control unit 160. When receiving a low level from the control unit 160, the transistor Q1 is in a cut-off state, and its collector is connected to the first isolating switch 142, outputting a high level to the first isolating switch 142. The first isolating switch 142 is in a cut-off state when receiving a high level. At this time, when the base of the transistor Q1 receives a high level from the control unit 160, the transistor Q1 is turned on, and its collector is grounded to output a low level to the first isolating switch 142. The first isolating switch 142 is in a turned-on state when receiving the low level.

[0046] Optionally, the first isolation switch 142 includes a thyristor isolation chip IC1, a resistor R3, a resistor R4, and a resistor R5, a first pin of the thyristor isolation chip IC1 is connected to a DC power supply unit, a second pin of the thyristor isolation chip IC1 is connected to the collector of the transistor Q1 via the resistor R3, and a sixth pin of the thyristor isolation chip IC1 is connected to the second end of the voltage divider circuit 131 via the resistor R5 and the resistor R4 connected in series. Specifically, in the first isolation switch 142, the first pin of the thyristor isolation chip IC1 is connected to the DC power supply unit to input a DC voltage, and the second pin thereof is connected to the second sub-switch 141. When the second sub-switch 141 is in the off state, the voltage of the second pin of the thyristor isolation chip IC1 is at a high level. At this time, the first pin and the second pin of the thyristor isolation chip IC1 are both at a high level, the chip is in the off state, and its output end has no output. When the second sub-switch 141 is in the on state, the voltage of the second pin of the thyristor isolation chip IC1 is at a low level. At this time, a voltage difference is formed between the first pin and the second pin of the thyristor isolation chip IC1, and the fourth pin and the sixth pin of the chip are in the on state to drive the first sub-switch 132 to turn on.

[0047] Optionally, the third sub-switch 151 includes a MOS transistor Q2, a resistor R6, a resistor R7 and a resistor R10; the gate of the MOS transistor Q2 is connected to the second end of the voltage divider circuit 131 via the resistor R10, the source of the MOS transistor Q2 is connected to the second input end 122, the drain of the MOS transistor Q2 is connected to the first input end 121 via the resistor R6 and the resistor R7 connected in series, and the drain of the MOS transistor Q2 is connected to the first end of the second isolation switch 152; specifically, in the third sub-switch 151, the gate of the MOS transistor Q2 is connected to the voltage divider circuit 131 via the resistor R10, when the voltage divider circuit 131 has no voltage division or the voltage division is smaller than the turn-on voltage of the MOS transistor Q2, that is, the gate threshold voltage, the MOS transistor Q2 is turned off, and at this time, a voltage difference is formed between the drain and the source of the MOS transistor Q2, so that the second isolation switch 152 is in the on state, and the corresponding pin input of the timing unit 170 is at a low level. When the divided voltage of the voltage divider circuit 131 increases to be greater than the turn-on voltage of the MOS tube Q2, that is, the gate threshold voltage, the MOS tube Q2 is turned on. At this time, the drain and the source of the MOS tube Q2 are turned on, and there is no large voltage difference between them. The second isolation switch 152 is in the off state, and the corresponding pin input of the timing unit 170 is at a high level.

[0048] Optionally, the second isolation switch 152 includes an optocoupler chip U2, a first pin of the optocoupler chip U2 is connected to the drain of the MOS tube Q2, a second pin of the optocoupler chip U2 is connected to the second input terminal 122, a third pin of the optocoupler chip U2 is grounded, and a fourth pin of the optocoupler chip U2 is connected to the timing unit 170. Specifically, when the MOS tube Q2 is turned off, there is a voltage difference between the first pin and the second pin of the optocoupler chip U2, so that the third pin and the fourth pin thereof are turned on, the level of the fourth pin is pulled down by the grounded third pin, and the corresponding pin of the timing unit 170 is at a low level. When the MOS tube Q2 is turned on, there is no large voltage difference between the first pin and the second pin of the optocoupler chip U2, and the first pin and the second pin thereof are in a turned-off state, so that the third pin and the fourth pin thereof are turned off, the level of the fourth pin is pulled up by the DC power supply unit, and the corresponding pin of the timing unit 170 is at a high level.

[0049] Optional, such as Figure 2 and Figure 3 As shown, the timing unit 170, the processing unit 180 and the control unit 160 are integrated into a control chip 300. Specifically, the timing unit 170, the processing unit 180 and the control unit 160 can be implemented by an integrated chip U1, and the device model of the integrated chip U1 can be MC96F8216SD. That is, the pin level timing function and the output control level function are configured in the integrated chip, and the relationship between the AC input voltage and the conduction time of the second switch unit 150 is also configured to be stored.

[0050] Optionally, the first input terminal 121 is an ACL terminal for AC power input, and the second input terminal 122 is a CAN terminal for AC power input. Specifically, the first input terminal 121 and the second output terminal connected to the AC working circuit 200 can correspond to the ACL terminal, i.e., the live wire input terminal of the AC power, and the ACN terminal, i.e., the neutral wire input terminal of the AC power, respectively.

[0051] In addition, an electronic device of the present invention includes: an AC working circuit 200 and an AC input detection circuit 100 as any one of the above, wherein the AC working circuit 200 includes a heating circuit. Specifically, in an electronic device, the AC working circuit 200 can be a heating circuit, and an AC input detection circuit connected to the AC working circuit 200 is provided to detect the AC input parameters of the AC working circuit 200. It can be understood that the electronic device can be a household device such as a soybean milk machine, a wall breaking machine, etc.

[0052] In addition, Figure 5As shown, an AC input detection method of the present invention is applied to the AC input detection circuit 100 described above, and the process includes: S1, triggering the first switch unit 140 to turn on through the control unit 160 to trigger the voltage extraction unit 130 to generate a driving voltage corresponding to the AC input, wherein the control unit 160 triggers the first switch unit 140 to turn on for a time greater than the half-wave period of the AC input; S2, driving the second switch unit 150 to turn on through the driving voltage, and obtaining the actual continuous conduction time of the second switch unit 150 when the second switch unit 150 is triggered to turn on; S3, obtaining the corresponding AC input voltage from the storage unit 190 according to the actual continuous conduction time. Specifically, when the AC working circuit 200 is working, its AC input is a sine or cosine voltage, that is, it increases or decreases with time. When the control unit 160 triggers the first switch unit 140 to turn on so that the AC input of the AC working circuit 200 forms a loop, the driving voltage generated by the voltage extraction unit 130 in the loop is in a corresponding relationship with the AC input. That is, it can be understood that when the AC input increases, the driving voltage generated by the voltage extraction unit 130 becomes larger, and when the AC input decreases, the driving voltage generated by the voltage extraction unit 130 becomes smaller. When the driving voltage reaches the conduction threshold of the second switch unit 150, the second switch unit 150 is turned on, until the driving voltage is less than the conduction threshold of the second switch unit 150, the second switch unit 150 is turned off. At this time, the timing unit 170 records the duration of the conduction of the second switch unit 150, which can be the corresponding AC input. Figure 3 As shown, V1, V2, and V3 in the AC input current and voltage waveform are different AC inputs, where Vth is the conduction voltage of the second switch unit 150. Under different AC inputs, the continuous conduction time t1, t2, and t3 of the second switch unit 150 are different. The timing unit 170 can obtain the AC input voltage according to the preset relationship between the timing t1, t2, and t3 and V1, V2, and V3. At the same time, the control unit 160 is set to trigger the conduction time of the first switch unit 140 to be greater than the half-wave period of the AC input. At this time, the actual continuous conduction time obtained by the timing unit 170 corresponds to the voltage change process in a complete half-wave, so as to ensure the accuracy of the test results.

[0053] Optional, such as Figure 6As shown, an AC input detection method of the present invention further includes: S4, obtaining the number of conduction times of the second switch unit 150 within a preset time and multiple actual continuous conduction durations corresponding to the number of conduction times; S5, obtaining the average continuous conduction duration corresponding to the preset time according to the multiple actual continuous conduction durations and the number of conduction times, so as to obtain the AC input voltage within the preset time from the storage unit 190 according to the average continuous conduction duration. Specifically, in order to ensure the accuracy of the test result, the number of conduction times of the second switch unit 150 is recorded, and the actual continuous conduction duration corresponding to each conduction is recorded, and the average continuous conduction duration is obtained according to the sum of the actual continuous conduction durations corresponding to multiple conductions and the number of conduction times, so as to obtain the corresponding AC input voltage according to the average continuous conduction duration. It can be understood that there may be changes in the AC input, and the sampling time of the average continuous conduction duration can be set as needed to obtain the AC input voltage corresponding to the corresponding sampling time.

[0054] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. An AC input detection circuit, characterized in that: include: A DC power supply unit for providing a DC voltage, comprising an AC power input terminal having a first input terminal and a second input terminal, a voltage extraction unit connected to the second input terminal, and a first switch unit connected to the voltage extraction unit, wherein the first input terminal is used to connect to an AC working circuit, the second input terminal is used to connect to the AC working circuit via the voltage extraction unit, and the voltage extraction unit is used to generate a driving voltage corresponding to the AC input when the first switch unit is turned on; and A control unit connected to the first switch unit and configured to output a first switch control level to control the first switch unit to be turned on or off; A second switch unit connected to the voltage extraction unit and the first input terminal and configured to receive the driving voltage to switch on or off; A timing unit connected to the second switch unit and used to record the actual continuous conduction time of the second switch unit; a storage unit for storing a corresponding relationship between a preset continuous conduction time length of the conduction of the second switch unit and an AC input voltage; A processing unit connected to the timing unit and the storage unit and configured to obtain the actual continuous conduction time and obtain the corresponding AC input voltage from the storage unit.

2. The AC input detection circuit according to claim 1, characterized in that: The voltage extraction unit includes a voltage dividing circuit and a first sub-switch; The first end of the voltage divider circuit is connected to the second input end, the second end of the voltage divider circuit is connected to the first end of the first sub-switch, the first switch unit and the second switch unit, the second end of the first sub-switch is used to connect to the AC working circuit, and the third end of the first sub-switch is connected to the first switch unit.

3. The AC input detection circuit according to claim 2, characterized in that: The first switch unit includes a second sub-switch and a first isolating switch; a first end of the second sub-switch is connected to the control unit, a second end of the second sub-switch is connected to the DC power supply unit, a third end of the second sub-switch is connected to the second end of the first isolating switch, a first end of the first isolating switch is connected to the DC power supply unit, a third end of the first isolating switch is connected to the third end of the first sub-switch, and a fourth end of the first isolating switch is connected to the second end of the voltage divider circuit; and / or The second switch unit includes a third sub-switch and a second isolating switch; the first end of the third sub-switch is connected to the second input end, the second end of the third sub-switch is connected to the second end of the voltage divider circuit, the third end of the third sub-switch is connected to the first end of the second isolating switch, the second end of the second isolating switch is connected to the second input end, the third end of the second isolating switch is grounded, and the fourth end of the second isolating switch is connected to the timing unit.

4. The AC input detection circuit according to claim 3, characterized in that: The first sub-switch comprises a thyristor switch TR1, wherein the A1 pin of the thyristor switch TR1 is connected to the AC working circuit, the A2 pin of the thyristor switch TR1 is connected to the voltage divider circuit, and the G pin of the thyristor switch TR1 is connected to the first isolation switch; and / or The voltage divider circuit includes a resistor R11 and a resistor R12. The resistor R11 and the resistor R12 are connected in parallel, one end of which is connected to the second input end, and the other end of which is connected to the first end of the first sub-switch and the second end of the third sub-switch.

5. The AC input detection circuit according to claim 3, characterized in that: The second sub-switch includes a transistor Q1 and a resistor R2; the base of the transistor Q1 is connected to the control unit, the base of the transistor Q1 is grounded via the resistor R2, the emitter of the transistor Q1 is grounded, and the collector of the transistor Q1 is connected to the DC power supply unit and the first isolation switch; and / or The first isolating switch includes a thyristor isolation chip IC1, a resistor R3, a resistor R4 and a resistor R5. The first pin of the thyristor isolation chip IC1 is connected to the DC power supply unit, the second pin of the thyristor isolation chip IC1 is connected to the collector of the transistor Q1 via the resistor R3, and the sixth pin of the thyristor isolation chip IC1 is connected to the second end of the voltage divider circuit via the resistor R5 and the resistor R4 connected in series.

6. The AC input detection circuit according to claim 3, characterized in that: The third sub-switch includes a MOS transistor Q2, a resistor R6, a resistor R7 and a resistor R10; the gate of the MOS transistor Q2 is connected to the second end of the voltage divider circuit via the resistor R10, the source of the MOS transistor Q2 is connected to the second input end, the drain of the MOS transistor Q2 is connected to the first input end via the resistor R6 and the resistor R7 connected in series, and the drain of the MOS transistor Q2 is connected to the first end of the second isolation switch; and / or The second isolating switch includes an optocoupler chip U2, a first pin of the optocoupler chip U2 is connected to the drain of the MOS tube Q2, a second pin of the optocoupler chip U2 is connected to the second input end, a third pin of the optocoupler chip U2 is grounded, and a fourth pin of the optocoupler chip U2 is connected to the timing unit.

7. The AC input detection circuit according to claim 1, characterized in that: The timing unit, the processing unit and the control unit are integrated into a control chip U1.

8. The AC input detection circuit according to claim 1, characterized in that: The first input end is an ACL end for inputting an AC power source, and the second input end is a CAN end for inputting an AC power source.

9. An electronic device, characterized in that: include: An AC working circuit and an AC input detection circuit as claimed in any one of claims 1 to 8.

10. An AC input detection method, characterized in that: Applicable to the AC input detection circuit as claimed in any one of claims 1 to 8; The process includes: S1. Triggering the first switch unit to turn on through a control unit to trigger the voltage extraction unit to generate a driving voltage corresponding to an AC input, wherein the control unit triggers the first switch unit to turn on for a time greater than a half-wave period of the AC input; S2, driving the second switch unit to turn on by the driving voltage, and obtaining an actual continuous conduction time length of the second switch unit when the second switch unit is triggered to turn on; S3. Obtain a corresponding AC input voltage from the storage unit according to the actual continuous conduction time.

11. The AC input detection method according to claim 10, characterized in that: The method further comprises: S4, obtaining the number of times the second switch unit is turned on within a preset time and a plurality of actual continuous turn-on time durations corresponding to the number of times; S5. Obtain an average continuous conduction time corresponding to the preset time according to the multiple actual continuous conduction time and the number of conduction times, so as to obtain the AC input voltage within the preset time from the storage unit according to the average continuous conduction time.

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