Door handle signal acquisition circuit

Abstract

The utility model provides a door handle signal acquisition circuit which comprises a first current control circuit, a reference circuit and a comparison circuit, the first current control circuit is controlled to be switched on or switched off through a periodic control signal representing the state of a load, when the first current control circuit is switched on, a first current signal supplies power to the load in an awakening state, and when the first current control circuit is switched off, a second current signal supplies power to the load in an awakening state. The reference circuit can obtain the power supply voltage to generate a threshold signal, and the comparison circuit can obtain the power supply voltage through the power supply end of the comparison circuit, so that the comparison circuit is electrified to work, and the threshold signal and the first current signal are compared to obtain a door handle signal. For example, a door handle signal represented as a level signal can be obtained through conversion of a comparison circuit to represent the state of a load, whether the load is manually sensed and operated or not is judged, and the function of compatibility of two-wire system and three-wire system door handle signal acquisition is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to signal acquisition technical field, especially a door handle signal acquisition circuit. BACKGROUND

[0002] The acquisition of two-wire system and three-wire system door handle signals usually needs to adopt the mode of selecting a device to realize, so as to cause needing two versions of hardware, so that the platform design is not friendly to the customer, and the control cost of spare part suppliers is increased. UTILITY MODEL CONTENTS

[0003] The utility model provides a door handle signal acquisition circuit can compatible two-wire system and three-wire system door handle signal acquisition.

[0004] To solve the above technical problem, the utility model provides a door handle signal acquisition circuit, it includes:

[0005] The input end of the first current control circuit is connected with the power supply voltage, the current output end of the first current control circuit is connected with the load, and the control end of the first current control circuit is connected with the periodic control signal representing the state of the load to be turned on or turned off by the periodic control signal.

[0006] The input end of the reference circuit is connected with the voltage output end of the first current control circuit, and the output end of the reference circuit is used to output a threshold signal.

[0007] The first input end of the comparison circuit is connected with the output end of the reference circuit, the second input end of the comparison circuit is connected with the current output end of the first current control circuit, and the power supply end of the comparison circuit is connected with the voltage output end of the first current control circuit.

[0008] When the first current control circuit is turned on, the power supply voltage is output at the voltage output end of the first current control circuit, and the first current signal converted from the power supply voltage is output at the current output end of the first current control circuit, and the comparison circuit outputs the door handle signal based on the comparison result of the threshold signal and the first current signal.

[0009] Optionally, when the first current signal is greater than the threshold signal, the door handle signal is low level, and when the first current signal is less than the threshold signal, the door handle signal is high level.

[0010] Optionally, the first current control circuit comprises a driving unit, a first switch tube and a sixth resistor, a first end of the first switch tube is connected to a power supply voltage, a second end of the first switch tube is connected to the load through the sixth resistor, a control end of the first switch tube is connected to the driving unit, and the driving unit is enabled by the periodic control signal to turn on or turn off the first switch tube.

[0011] Optionally, the driving unit comprises a first resistor, a second resistor, a third resistor, a first diode and a second switch tube, a first end of the first resistor is connected to the power supply voltage, a second end of the first resistor is connected to a first end of the second switch tube through the second resistor, a second end of the second switch tube is grounded, a control end of the second switch tube is connected to the periodic control signal, one end of the third resistor is connected to the control end of the second switch tube, the other end of the third resistor is grounded, the control end of the first switch tube is connected to the second end of the first resistor, a cathode end of the first diode is connected to the power supply voltage, and an anode end of the first diode is connected to the second end of the first resistor.

[0012] Optionally, the reference circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a second diode, a sixth switch tube and a seventh switch tube, a first end of each of the eleventh resistor, the twelfth resistor and the thirteenth resistor is connected to a voltage output end of the first current control circuit, a second end of the eleventh resistor is connected to a cathode end of the second diode and a control end of the sixth switch tube, an anode end of the second diode and a second end of the sixth switch tube are grounded, a first end of the sixth switch tube is connected to a second end of the twelfth resistor and a control end of the seventh switch tube, a first end of the seventh switch tube is connected to a second end of the thirteenth resistor and a first input end of the comparison circuit, and a second end of the seventh switch tube is grounded through the fourteenth resistor.

[0013] Optionally, the comparison circuit comprises an eighth resistor, a ninth resistor, a tenth resistor, a fourth switch tube and a fifth switch tube, a first end of the eighth resistor is a power supply end of the comparison circuit, a second end of the eighth resistor is connected to a first end of the fourth switch tube and a first end of the fifth switch tube, a control end of the fourth switch tube is a first input end of the comparison circuit, a control end of the fifth switch tube is a second input end of the comparison circuit, a second end of the fourth switch tube is grounded through the ninth resistor, a second end of the fifth switch tube is grounded through the tenth resistor, and the second end of the fifth switch tube is an output end of the comparison circuit.

[0014] Optionally, the door handle signal acquisition circuit further comprises a second current control circuit, an input end of the second current control circuit is connected to the power supply voltage, an output end of the second current control circuit is connected to the load, and the second current control circuit converts the power supply voltage into a second current signal, the second current signal being smaller than the first current signal.

[0015] Optionally, when the first current control circuit is off and the load requires a current being the first current signal, the second current control circuit generates an enable signal and outputs the enable signal to a control end of the first current control circuit, so as to turn on the first current control circuit.

[0016] Optionally, the second current control circuit comprises a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor and an eighth switch tube, a first end of the sixteenth resistor is connected to the power supply voltage, a second end of the sixteenth resistor is connected to the load, the fifteenth resistor and the seventeenth resistor are connected in series and then connected in parallel with the sixteenth resistor, a first end of the eighth switch tube is connected to the power supply voltage, a second end of the eighth switch tube is connected to the control end of the first current control circuit through the eighteenth resistor, and a control end of the eighth switch tube is connected between the fifteenth resistor and the seventeenth resistor.

[0017] Optionally, the door handle signal acquisition circuit further comprises an overcurrent detection circuit and an overcurrent protection circuit, a first end of the overcurrent protection circuit is connected to the control end of the first current control circuit, a second end of the overcurrent protection circuit is grounded, a control end of the overcurrent protection circuit is connected to the overcurrent detection circuit, and the overcurrent detection circuit turns on the overcurrent protection circuit when the first current signal is greater than a threshold current.

[0018] Optionally, the first current control circuit has a sixth resistor, one end of the sixth resistor is connected to a voltage output end of the first current control circuit, and the other end of the sixth resistor is used as a current output end of the first current control circuit; the overcurrent detection circuit comprises a fourth resistor, a fifth resistor, a seventh resistor and a third switch tube, the fourth resistor and the fifth resistor are connected in series and then connected in parallel with the sixth resistor, a first end of the third switch tube is connected to the voltage output end of the first current control circuit, a control end of the third switch tube is connected between the fourth resistor and the fifth resistor, and a second end of the third switch tube is connected to the control end of the overcurrent protection circuit through the seventh resistor.

[0019] Optionally, the overcurrent protection circuit comprises a nineteenth resistor, a twentieth resistor and a ninth switch tube, one end of the nineteenth resistor is used as a control end of the overcurrent protection circuit, the other end of the nineteenth resistor is connected to ground through the twentieth resistor, the first end of the ninth switch tube is connected to the control end of the first current control circuit, the second end of the ninth switch tube is connected to ground, and the control end of the ninth switch tube is connected between the nineteenth resistor and the twentieth resistor.

[0020] The door handle signal acquisition circuit as above controls the first current control circuit to be turned on or turned off through the periodic control signal representing the state of the load (such as a capacitive door handle), the first current control circuit is turned on, the first current signal supplies power to the load in the wake-up state, the reference circuit can obtain the power voltage to generate the threshold signal, and the comparison circuit can obtain the power voltage through the power supply end of the comparison circuit, so that the comparison circuit is powered on, compares the threshold signal and the first current signal, and obtains the door handle signal based on the comparison result. For example, when the load is in the wake-up state and the load is artificially induced, the current required by the load will increase, so that the first current signal is greater than or equal to the threshold signal, and the output door handle signal is represented as a low level. When the load is not artificially induced, the first current signal is less than the threshold signal, and the door handle signal is represented as a high level. In this way, the state of the load can be represented by the door handle signal converted by the comparison circuit to represent a level signal to determine whether the load is artificially induced and operated, thereby realizing the function of the door handle signal acquisition compatible with two-wire and three-wire systems. BRIEF DESCRIPTION OF DRAWINGS

[0021] Those skilled in the art should understand that the provided drawings are used to better understand the present application, and do not constitute any limitation on the scope of the present application. Among them:

[0022] Figure 1 is a schematic diagram of a door handle signal acquisition circuit according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the purpose, advantages and characteristics of the present application clearer, the present application will be further described in detail below in combination with the drawings and specific embodiments. It should be noted that the drawings are very simplified and not drawn to scale, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present application. In addition, the structures shown in the drawings are often part of the actual structure. In particular, different scales are sometimes used in different emphasis of the drawings.

[0024] As used in the present application, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. The term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise. The term "plurality" is generally employed in its sense including "at least one" unless the context clearly dictates otherwise. The term "at least two" is generally employed in its sense including "two or more" unless the context clearly dictates otherwise. In addition, the terms "first", "second", "third", etc. are used only to describe the order of the features and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second", "third" can explicitly or implicitly include one or at least two of the features. "One end" and "the other end" and "proximal end" and "distal end" generally refer to the two parts corresponding to each other, which not only includes the end point, and the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. In addition, as used in the present application, a component is provided in another component, which generally only indicates that there is a connection, coupling, cooperation or transmission relationship between the two components, and the two components can be directly connected, coupled, cooperated or transmitted, or indirectly connected, coupled, cooperated or transmitted through an intermediate component, and cannot be understood as indicating or implying the spatial positional relationship between the two components, i.e. one component can be in any direction inside, outside, above, below or one side of another component, unless the context clearly indicates otherwise. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] Figure 1 is a schematic diagram of a door handle signal acquisition circuit of an embodiment of the present application. As shown in Figure 1 , the present application provides a door handle signal FB acquisition circuit, which includes a first current control circuit 10, a reference circuit 20, a comparison circuit 30, a second current control circuit 40, an overcurrent detection circuit 50 and an overcurrent protection circuit 60. The following will describe each part of the circuit.

[0026] As to the first current control circuit 10, the input terminal of the first current control circuit 10 is connected to the power supply voltage VCC, the current output terminal of the first current control circuit 10 is connected to the load 70, and the control terminal of the first current control circuit 10 is connected to the periodic control signal CTL representing the state of the load 70, so as to be turned on or turned off by the periodic control signal CTL. When the first current control circuit 10 is turned on, the first current control circuit 10 outputs the power supply voltage VCC at the voltage output terminal thereof, and converts the power supply voltage VCC into a first current signal and outputs the first current signal at the current output terminal thereof, so as to output the first current signal to the load 70, thereby meeting the large current supply requirement of the load 70. Referring to Figure 1 , the voltage output terminal of the first current control circuit 10 is the circuit node A, and the current output terminal of the first current control circuit 10 is the circuit node B.

[0027] In an embodiment, the load 70 is a door handle (for example, a capacitive door handle), the door handle periodically enters the wake-up state and the sleep state, the current required by the door handle in the wake-up state is less than the current required by the door handle in the sleep state, the door handle in the sleep state is also referred to as the door handle working in the low-power-consumption mode, thereby saving power consumption, and when the door handle is in the wake-up state, the door handle can be unlocked, locked and the like after being touched by a person and sensed, the periodic control signal CTL represents that the door handle is in the wake-up state or the sleep state, the periodic control signal CTL turns on the first current control circuit 10 when the door handle is in the wake-up state, and the periodic control signal CTL turns off the first current control circuit 10 when the door handle is in the sleep state.

[0028] Further, the first current control circuit 10 comprises a driving unit 11, a first switch tube Q1 and a sixth resistor R6, the first terminal of the first switch tube Q1 is used as the input terminal of the first current control circuit 10, so as to be connected to the power supply voltage VCC, the second terminal of the first switch tube Q1 is used as the voltage output terminal (the circuit node A) of the first current control circuit 10, and is connected to the first terminal of the sixth resistor R6, the second terminal of the sixth resistor R6 is used as the current output terminal of the second current control circuit 40, and is connected to the load 70, and the control terminal of the first switch tube Q1 is connected to the driving unit 11, the driving unit 11 is enabled by the periodic control signal CTL, so as to turn on or turn off the first switch tube Q1. When the first switch tube Q1 is turned on, the power supply voltage VCC is converted into the first current signal by the sixth resistor R6, and the first current signal is output to the load 70, thereby meeting the large current supply requirement of the load 70 in the wake-up state.

[0029] For example, the first switch tube Q1 can be a PMOS tube, the first terminal of the first switch tube Q1 is the source electrode of the PMOS tube, the second terminal of the first switch tube Q1 is the drain electrode of the PMOS tube, and the control terminal of the first switch tube Q1 is the gate electrode of the PMOS tube.

[0030] In an embodiment, the driving unit 11 comprises a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1 and a second switch Q2. The first end of the first resistor R1 is connected to a power supply voltage VCC, the second end of the first resistor R1 is connected to the first end of the second switch Q2 through the second resistor R2, the second end of the second switch Q2 is grounded, the control end of the second switch Q2 is connected to a periodic control signal CTL, one end of the third resistor R3 is connected to the control end of the second switch Q2, the other end of the third resistor R3 is grounded, the control end of the first switch Q1 is connected to the second end of the first resistor R1, the cathode end of the first diode D1 is connected to the power supply voltage VCC, and the anode end of the first diode D1 is connected to the second end of the first resistor R1. The first diode D1 is used as a clamping diode to clamp the voltage between the first end and the control end of the first switch Q1, so that when the second switch Q2 is turned on by the periodic control signal CTL, the first switch Q1 can be stably turned on.

[0031] For example, the second switch Q2 is an NMOS tube, the first end of the second switch Q2 is the drain of the NMOS tube, the second end of the second switch Q2 is the source of the NMOS tube, and the control end of the second switch Q2 is the gate of the NMOS tube.

[0032] Regarding the reference circuit 20. The input end of the reference circuit 20 is connected to the voltage output end of the first current control circuit 10, and the output end of the reference circuit 20 is used to output a threshold signal. Specifically, when the first current control circuit 10 is turned on by the periodic control signal CTL, the reference circuit 20 can obtain the power supply voltage VCC, so as to generate a threshold signal based on the power supply voltage VCC, and output the threshold signal to the first input end of the comparison circuit 30 (M). Figure 1 The threshold signal here can be a voltage signal or a current signal.

[0033] In an embodiment, the threshold signal is a voltage signal, and the reference circuit 20 comprises an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a second diode D2, a sixth switch tube Q6 and a seventh switch tube Q7. The first ends of the eleventh resistor R11, the twelfth resistor R12 and the thirteenth resistor R13 are connected together as an input terminal of the reference circuit 20, and are connected to a voltage output terminal of the first current control circuit 10. The second end of the eleventh resistor R11 is connected to a cathode terminal of the second diode D2 and a control terminal of the sixth switch tube Q6. An anode terminal of the second diode D2 and a second terminal of the sixth switch tube Q6 are both grounded. The first terminal of the sixth switch tube Q6 is connected to a second terminal of the twelfth resistor R12 and a control terminal of the seventh switch tube Q7. The first terminal of the seventh switch tube Q7 is connected to a second terminal of the thirteenth resistor R13 and a first input terminal of the comparison circuit 30. The second terminal of the seventh switch tube Q7 is grounded through the fourteenth resistor R14. Thus, the first terminal of the first switch tube Q1 is an output terminal of the reference circuit 20. When the first current control circuit 10 is turned on, the first current control circuit 10 outputs the power supply voltage VCC at the voltage output terminal thereof, so as to output to the reference circuit 20. Through the configuration relationship of the components of the reference circuit 20, the sixth switch tube Q6 and the seventh switch tube Q7 are sequentially turned on, so as to output the threshold signal at the first terminal of the seventh switch tube Q7.

[0034] For example, the sixth switch tube Q6 is a PNP triode, the first terminal of the sixth switch tube Q6 is an emitter of the PNP triode, the second terminal of the sixth switch tube Q6 is a collector of the PNP triode, and the control terminal of the sixth switch tube Q6 is a base of the PNP triode. The seventh switch tube Q7 is an NPN triode, the first terminal of the seventh switch tube Q7 is a collector of the NPN triode, the second terminal of the seventh switch tube Q7 is an emitter of the NPN triode, and the control terminal of the seventh switch tube Q7 is a base of the NPN triode.

[0035] As to the comparison circuit 30. The first input terminal of the comparison circuit 30 is connected to the output terminal of the reference circuit 20, so as to obtain the threshold signal. The second input terminal of the comparison circuit 30 is connected to the output terminal of the first current control circuit 10, so as to obtain the current signal. The output terminal of the comparison circuit 30 is connected to the control terminal of the first switch tube Q1. Figure 1As shown, the second input end of the comparison circuit 30 is connected to the current output end of the first current control circuit 10, so as to obtain the first current signal, and the power supply end of the comparison circuit 30 is connected to the voltage output end of the first current control circuit 10. When the first current control circuit 10 is turned on, the comparison circuit 30 can obtain the power supply voltage VCC through the power supply end thereof, so that the comparison circuit 30 is powered on to work, compare the threshold signal and the first current signal, and obtain the door handle signal FB based on the comparison result. For example, when the load 70 is in the wake-up state and the load 70 is artificially induced, the current required by the load 70 will increase, so that the first current signal is greater than or equal to the threshold signal, and the output door handle signal FB is represented as a low level. When the load 70 is not artificially induced, the first current signal is less than the threshold signal, and the door handle signal FB is represented as a high level. In this way, the state of the load 70 can be represented by the door handle signal FB converted by the comparison circuit 30 and represented as a level signal, so as to determine whether the load 70 is artificially induced, and realize the function of collecting the door handle signal FB compatible with two-wire system and three-wire system. It should be noted that the threshold signal can be a voltage signal or a current signal. When the threshold signal is a current signal, the comparison circuit 30 can directly compare the threshold signal with the first current signal. When the threshold signal is a voltage signal, the first current signal can be converted into a corresponding first voltage signal, so as to compare the threshold signal with the first voltage signal.

[0036] In an embodiment, the comparison circuit 30 includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a fourth switch tube Q4 and a fifth switch tube Q5. The first end of the eighth resistor R8 is connected to the voltage output end of the first current control circuit 10 as the power supply end of the comparison circuit 30. The second end of the eighth resistor R8 is connected to the first end of the fourth switch tube Q4 and the first end of the fifth switch tube Q5. The control end of the fourth switch tube Q4 is the first input end of the comparison circuit 30. The control end of the fifth switch tube Q5 is the second input end of the comparison circuit 30. The second end of the fourth switch tube Q4 is grounded through the ninth resistor R9. The second end of the fifth switch tube Q5 is grounded through the tenth resistor R10. The second end of the fifth switch tube Q5 is the output end of the comparison circuit 30, and is used to output the door handle signal FB.

[0037] For example, the fourth switch tube Q4 is a PNP triode, the first end of the fourth switch tube Q4 is the emitter of the PNP triode, the second end of the fourth switch tube Q4 is the collector of the PNP triode, and the control end of the fourth switch tube Q4 is the base of the PNP triode. The fifth switch tube Q5 is a PNP triode, the first end of the fifth switch tube Q5 is the emitter of the PNP triode, the second end of the fifth switch tube Q5 is the collector of the PNP triode, and the control end of the fifth switch tube Q5 is the base of the PNP triode.

[0038] As to the second current control circuit 40, the input end of the second current control circuit 40 is connected to the power supply voltage VCC, the output end of the second current control circuit 40 is connected to the load 70, and the second current control circuit 40 converts the power supply voltage VCC into a second current signal, which is smaller than the first current signal. Thus, when the periodic control signal CTL turns off the first current control circuit 10, the second current control circuit 40 can continue to supply power to the load 70 in the sleep state, satisfying the low-power consumption demand of the load 70. In an embodiment, the second current control circuit 40 includes a sixteenth resistor R16, one end of the sixteenth resistor R16 is connected to the power supply voltage VCC, and the other end of the sixteenth resistor R16 is connected to the load 70, so as to convert the power supply voltage VCC into the second current signal. Thus, the resistance of the sixteenth resistor R16 will be much larger than the resistance of the sixth resistor R6.

[0039] Further, when the first current control circuit 10 is turned off and the load 70 needs a current of the first current signal, the second current control circuit 40 generates an enable signal and outputs the enable signal to the control end of the first current control circuit 10, so as to turn on the first current control circuit 10. Specifically, when the load 70 is in the sleep state, the first current control circuit 10 is turned off. If the load 70 (capacitive door handle) is touched by a person at this time, the load 70 needs to enter the wake-up state and needs to be supplied with a large current at this time. At this time, the second current signal provided by the second current control circuit 40 cannot meet the demand, and the second current control circuit 40 will generate the enable signal to turn on the first current control circuit 10, so that the first current control circuit 10 can supply power to the load 70 in the wake-up state at this time.

[0040] In an embodiment, the second current control circuit 40 includes a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, and an eighth switch tube Q8. The first end of the sixteenth resistor R16 is connected to the power supply voltage VCC, the second end of the sixteenth resistor R16 is connected to the load 70, the fifteenth resistor R15 and the seventeenth resistor R17 are connected in series and are connected in parallel with the sixteenth resistor R16, the first end of the eighth switch tube Q8 is connected to the power supply voltage VCC, the second end of the eighth switch tube Q8 is connected to the control end of the first current control circuit 10 through the eighteenth resistor R18, and the control end of the eighth switch tube Q8 is connected between the fifteenth resistor R15 and the seventeenth resistor R17. Thus, when the load 70 is in the sleep state and is touched by a person, the current needed will increase, and the voltage drop on the sixteenth resistor R16 will also increase, so that the voltage drop of the fifteenth resistor R15 will also increase, thereby turning on the eighth switch tube Q8, generating the enable signal based on the power supply voltage VCC and the eighteenth resistor R18, and turning on the first current control circuit 10, so that the first current control circuit 10 can meet the large-current power supply demand of the load 70 in the wake-up state.

[0041] For example, the eighth switch Q8 is a PNP transistor, the first end of the eighth switch Q8 is the emitter of the PNP transistor, the second end of the eighth switch Q8 is the collector of the PNP transistor, and the control end of the eighth switch Q8 is the base of the PNP transistor.

[0042] As to the over-current detection circuit 50 and the over-current protection circuit 60, the first end of the over-current protection circuit 60 is connected to the control end of the first current control circuit 10, the second end of the over-current protection circuit 60 is grounded, the control end of the over-current protection circuit 60 is connected to the over-current detection circuit 50, and the over-current detection circuit 50 turns on the over-current protection circuit 60 when the first current signal is greater than the set threshold current. In this way, when the over-current detection circuit 50 detects that the first current signal is over-current, the over-current detection circuit 50 turns on the over-current protection circuit 60, so that the over-current protection circuit 60 grounds the signal input to the control end of the first current control circuit 10 (specifically, the periodic control signal CTL is grounded, and the enable signal generated by the second current control circuit 40 is grounded), and then the first current control circuit 10 is not driven by the periodic control signal CTL or the enable signal, the first current control circuit 10 is turned off, the generation of the first current signal is stopped, and the over-current protection of the load 70 is realized.

[0043] In an embodiment, the over-current detection circuit 50 includes a fourth resistor R4, a fifth resistor R5, a seventh resistor R7, and a third switch Q3. The fourth resistor R4 and the fifth resistor R5 are connected in series and then connected in parallel with the sixth resistor R6. The first end of the third switch Q3 is connected to the voltage output end of the first current control circuit 10, the control end of the third switch Q3 is connected between the fourth resistor R4 and the fifth resistor R5, the second end of the third switch Q3 is connected to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is connected to the control end of the over-current protection circuit 60. In this way, when the first current signal is over-current, the third switch Q3 will be turned on, thereby generating a corresponding signal at the second end of the seventh resistor R7 to turn on the over-current protection circuit 60.

[0044] For example, the third switch Q3 is a PNP transistor, the first end of the third switch Q3 is the emitter of the PNP transistor, the second end of the third switch Q3 is the collector of the PNP transistor, and the control end of the third switch Q3 is the base of the PNP transistor.

[0045] In an embodiment, the overcurrent protection circuit 60 comprises a nineteenth resistor R19, a twentieth resistor R20 and a ninth switch tube Q9, one end of the nineteenth resistor R19 is the control end of the overcurrent protection circuit 60, the other end of the nineteenth resistor R19 is grounded through the twentieth resistor R20, the first end of the ninth switch tube Q9 is connected to the control end of the first current control circuit 10, the second end of the ninth switch tube Q9 is grounded, and the control end of the ninth switch tube Q9 is connected between the nineteenth resistor R19 and the twentieth resistor R20. In this way, when the overcurrent detection circuit 50 detects that the first current signal is overcurrent, the overcurrent detection signal output signal is output to the first end of the nineteenth resistor R19, and a corresponding signal is generated between the nineteenth resistor R19 and the twentieth resistor R20 to turn on the ninth switch tube Q9, so as to ground the signal input to the control end of the first current control circuit 10.

[0046] The ninth switch tube Q9 is an NPN triode, the first end of the ninth switch tube Q9 is the collector of the NPN triode, the second end of the ninth switch tube Q9 is the emitter of the NPN triode, and the control end of the ninth switch tube Q9 is the base of the PNP triode.

[0047] Although the utility model discloses as above with preferable embodiment, however, the above embodiment is not used to limit the utility model. For any skilled person in the art, without departing from the utility model technical scheme range, can utilize the technical content disclosed above to make many possible changes and modifications to the utility model technical scheme, or modify as equivalent variation equivalent embodiment. Therefore, any simple modification, equivalent variation and modification made to the above embodiment according to the technical essence of the utility model, all still belong to the protection scope of the utility model technical scheme.

Claims

1. A door handle signal acquisition circuit, characterized by The application relates to a current control circuit, comprising: a first current control circuit, an input end of which is connected to a power supply voltage, a current output end of which is connected to a load, and a control end of which is connected to a periodic control signal representing the state of the load to be turned on or turned off by the periodic control signal; a reference circuit, an input end of which is connected to the voltage output end of the first current control circuit, and an output end of which is used for outputting a threshold signal; a comparison circuit, a first input end of which is connected to the output end of the reference circuit, a second input end of which is connected to the current output end of the first current control circuit, and a power supply end of which is connected to the voltage output end of the first current control circuit; wherein the first current control circuit outputs the power supply voltage at the voltage output end thereof when being turned on, and outputs a first current signal converted from the power supply voltage at the current output end thereof, and the comparison circuit outputs a door handle signal based on the comparison result of the threshold signal and the first current signal.

2. The door handle signal acquisition circuit of claim 1, wherein, When the first current signal is greater than the threshold signal, the door handle signal is at a low level; and when the first current signal is less than the threshold signal, the door handle signal is at a high level.

3. The door handle signal acquisition circuit of claim 1, wherein, The first current control circuit comprises a driving unit, a first switch tube and a sixth resistor, a first end of the first switch tube is connected to the power supply voltage, a second end of the first switch tube is connected to the load through the sixth resistor, a control end of the first switch tube is connected to the driving unit, and the driving unit is enabled by the periodic control signal to turn on or turn off the first switch tube.

4. The door handle signal acquisition circuit of claim 3, wherein, The driving unit comprises a first resistor, a second resistor, a third resistor, a first diode and a second switch tube, a first end of the first resistor is connected to the power supply voltage, a second end of the first resistor is connected to a first end of the second switch tube through the second resistor, a second end of the second switch tube is grounded, a control end of the second switch tube is connected to the periodic control signal, one end of the third resistor is connected to the control end of the second switch tube, the other end of the third resistor is grounded, the control end of the first switch tube is connected to the second end of the first resistor, a cathode end of the first diode is connected to the power supply voltage, and an anode end of the first diode is connected to the second end of the first resistor.

5. The door handle signal acquisition circuit of claim 1, wherein, The reference circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a second diode, a sixth switch tube and a seventh switch tube, the first end of each of the eleventh resistor, the twelfth resistor and the thirteenth resistor is connected to the voltage output end of the first current control circuit, the second end of the eleventh resistor is connected to the cathode end of the second diode and the control end of the sixth switch tube, the anode end of the second diode and the second end of the sixth switch tube are grounded, the first end of the sixth switch tube is connected to the second end of the twelfth resistor and the control end of the seventh switch tube, the first end of the seventh switch tube is connected to the second end of the thirteenth resistor and the first input end of the comparison circuit, and the second end of the seventh switch tube is grounded through the fourteenth resistor.

6. The door handle signal acquisition circuit of claim 1, wherein, The comparison circuit comprises an eighth resistor, a ninth resistor, a tenth resistor, a fourth switch tube and a fifth switch tube, the first end of the eighth resistor is used as the power supply end of the comparison circuit, the second end of the eighth resistor is connected to the first end of the fourth switch tube and the first end of the fifth switch tube, the control end of the fourth switch tube is used as the first input end of the comparison circuit, the control end of the fifth switch tube is used as the second input end of the comparison circuit, the second end of the fourth switch tube is grounded through the ninth resistor, the second end of the fifth switch tube is grounded through the tenth resistor, and the second end of the fifth switch tube is used as the output end of the comparison circuit.

7. The door handle signal acquisition circuit of claim 1, wherein, The door handle signal acquisition circuit further comprises a second current control circuit, the input end of the second current control circuit is connected to the power supply voltage, the output end of the second current control circuit is connected to the load, and the second current control circuit converts the power supply voltage into a second current signal, and the second current signal is smaller than the first current signal.

8. The door handle signal acquisition circuit of claim 7, wherein, When the first current control circuit is turned off and the current required by the load is the first current signal, the second current control circuit generates an enable signal and outputs the enable signal to the control end of the first current control circuit, so as to turn on the first current control circuit.

9. The door handle signal acquisition circuit of claim 8, wherein, The second current control circuit comprises a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor and an eighth switch tube, the first end of the sixteenth resistor is connected to the power supply voltage, the second end of the sixteenth resistor is connected to the load, the fifteenth resistor and the seventeenth resistor are connected in series and are connected in parallel with the sixteenth resistor, the first end of the eighth switch tube is connected to the power supply voltage, the second end of the eighth switch tube is connected to the control end of the first current control circuit through the eighteenth resistor, and the control end of the eighth switch tube is connected between the fifteenth resistor and the seventeenth resistor.

10. The door handle signal acquisition circuit of claim 1, wherein, The door handle signal acquisition circuit further comprises an overcurrent detection circuit and an overcurrent protection circuit, a first end of the overcurrent protection circuit is connected to a control end of the first current control circuit, a second end of the overcurrent protection circuit is grounded, and a control end of the overcurrent protection circuit is connected to the overcurrent detection circuit.

11. The door handle signal acquisition circuit of claim 10, wherein, The first current control circuit has a sixth resistor, one end of the sixth resistor is connected to a voltage output end of the first current control circuit, and the other end of the sixth resistor serves as a current output end of the first current control circuit; the overcurrent detection circuit comprises a fourth resistor, a fifth resistor, a seventh resistor and a third switch tube, the fourth resistor and the fifth resistor are connected in series and then connected in parallel with the sixth resistor, a first end of the third switch tube is connected to the voltage output end of the first current control circuit, a control end of the third switch tube is connected between the fourth resistor and the fifth resistor, and a second end of the third switch tube is connected to the control end of the overcurrent protection circuit through the seventh resistor.

12. The door handle signal acquisition circuit of claim 10, wherein, The overcurrent protection circuit comprises a nineteenth resistor, a twentieth resistor and a ninth switch tube, one end of the nineteenth resistor serves as a control end of the overcurrent protection circuit, the other end of the nineteenth resistor is grounded through the twentieth resistor, a first end of the ninth switch tube is connected to the control end of the first current control circuit, a second end of the ninth switch tube is grounded, and a control end of the ninth switch tube is connected between the nineteenth resistor and the twentieth resistor.

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