Heating film control circuit and heating film control system

Abstract

The utility model relates to a heating film control circuit and a heating film control system. The first heating circuit is used for being connected with a to-be-controlled heating film in series and starting or stopping providing first working current for the to-be-controlled heating film according to the first heating control signal; the second heating circuit is used for being connected with the heating film to be controlled in series and starting or stopping providing second working current for the heating film to be controlled according to the second heating control signal; in a working state, the heating film control circuit alternately provides a first working current and a second working current for the heating film to be controlled, and the direction of the first working current is opposite to that of the second working current. On the basis, by alternately switching the current direction, the problems that in the prior art, due to the fact that fixed one-way current is adopted, electromigration happens to metal ions in a heating film conductor, electromigration failure is caused, and the service life of the heating film is seriously affected are solved, and the service life of the heating film is effectively prolonged.

Description

Technical Field

[0001] This application relates to the field of control circuit technology, and in particular to a heating film control circuit and a heating film control system. Background Technology

[0002] In outdoor camera products, a heating film is usually installed on the outside of the camera to cope with abnormal weather conditions, such as frost, ice or fog. The heating film generates heat to maintain a clear field of view of the camera lens and ensure the normal operation of the device. The lifespan of the heating film directly affects the reliability and durability of the entire product.

[0003] However, existing technologies suffer from the problem of short lifespan of heating films. Utility Model Content

[0004] Therefore, it is necessary to provide a heating film control circuit and a heating film control system to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a heating film control circuit, which includes a first heating circuit and a second heating circuit; wherein the first heating circuit is provided with a first control terminal; and the second heating circuit is provided with a second control terminal.

[0006] The control terminal of the first heating circuit is used to connect to the first control terminal of the main control circuit and receive the first heating control signal generated by the main control circuit; the first heating circuit is used to connect in series with the heating film to be controlled and to start or stop providing a first working current to the heating film to be controlled according to the first heating control signal.

[0007] The control terminal of the second heating circuit is used to connect to the second control terminal of the main control circuit and receive the second heating control signal generated by the main control circuit; the second heating circuit is used to connect in series with the heating film to be controlled and to start or stop providing a second operating current to the heating film to be controlled according to the second heating control signal.

[0008] When the heating film control circuit is in operation, it alternately provides the first working current and the second working current to the heating film to be controlled, wherein the direction of the first working current is opposite to the direction of the second working current.

[0009] In one embodiment, the first heating circuit includes a first switching circuit and a second switching circuit;

[0010] The first terminal of the first switching circuit is used to connect to the first control terminal of the main control circuit, the second terminal of the first switching circuit is used to connect to the first power supply, and the third terminal of the first switching circuit is used to connect to the first terminal of the heating film to be controlled; the first switching circuit is used to switch the on / off state according to the first heating control signal.

[0011] The first terminal of the second switching circuit is connected to the first terminal of the first switching circuit, the second terminal of the second switching circuit is used to connect to the second terminal of the heating film to be controlled, and the third terminal of the second switching circuit is grounded; the second switching circuit is used to switch the on / off state according to the first heating control signal.

[0012] In one embodiment, the first switching circuit includes a first switching transistor, a first resistor, and a first diode;

[0013] The first terminal of the first switching transistor is used to connect to the first control terminal of the main control circuit via the first resistor, the second terminal of the first switching transistor is used to connect to the first power supply, and the third terminal of the first switching transistor is connected to the positive terminal of the first diode.

[0014] The negative terminal of the first diode is used to connect to the first end of the heating film to be controlled.

[0015] In one embodiment, the second switching circuit includes a second switching transistor, a second resistor, a second diode, and a first logic circuit;

[0016] One end of the first logic circuit is connected to the connection point of the first control terminal and the first resistor of the main control circuit, and the other end of the first logic circuit is connected to the first terminal of the second switching transistor via the second resistor.

[0017] The second terminal of the second switching transistor is connected to the negative terminal of the second diode, and the third terminal of the second switching transistor is grounded.

[0018] The positive terminal of the second diode is used to connect to the second end of the heating film to be controlled.

[0019] In one embodiment, the first logic circuit is an inverter;

[0020] The first switching transistor is a PMOS transistor;

[0021] The second switch is an NMOS transistor.

[0022] In one embodiment, the second heating circuit includes a third switching circuit and a fourth switching circuit;

[0023] The first terminal of the third switching circuit is used to connect to the second control terminal of the main control circuit, the second terminal of the third switching circuit is used to connect to the second power supply, and the third terminal of the third switching circuit is used to connect to the connection point between the second terminal of the heating film to be controlled and the second terminal of the second switching circuit; the third switching circuit is used to switch the on / off state according to the second heating control signal.

[0024] The first terminal of the fourth switching circuit is connected to the first terminal of the third switching circuit, the second terminal of the fourth switching circuit is used to connect to the connection point between the first terminal of the heating film to be controlled and the third terminal of the first switching circuit, and the third terminal of the fourth switching circuit is grounded; the fourth switching circuit is used to switch the on / off state according to the second heating control signal.

[0025] In one embodiment, the third switching circuit includes a third switching transistor, a third resistor, and a third diode;

[0026] The first terminal of the third switch is used to connect to the second control terminal of the main control circuit via the third resistor, the second terminal of the third switch is used to connect to the second power supply, and the third terminal of the third switch is connected to the positive terminal of the third diode.

[0027] The negative terminal of the third diode is used to connect to the second end of the heating film to be controlled.

[0028] In one embodiment, the fourth switching circuit includes a fourth switching transistor, a fourth resistor, a fourth diode, and a second logic circuit.

[0029] One end of the second logic circuit is connected to the connection point of the second control terminal and the third resistor of the main control circuit, and the other end of the second logic circuit is connected to the first terminal of the fourth switch via the fourth resistor.

[0030] The second terminal of the fourth switching transistor is connected to the negative terminal of the fourth diode, and the third terminal of the fourth switching transistor is grounded.

[0031] The positive terminal of the fourth diode is used to connect to the first end of the heating film to be controlled.

[0032] In one embodiment, the second logic circuit is an inverter;

[0033] The third switch is a PMOS transistor;

[0034] The fourth switch is an NMOS transistor.

[0035] Secondly, this application also provides a heating film control system, which includes a main control circuit, a heating film control circuit as described in any of the embodiments of the first aspect above, a heating film to be controlled, a first power supply, and a second power supply.

[0036] The heating film control circuit is connected to the main control circuit, the heating film to be controlled, the first power supply, and the second power supply, respectively.

[0037] The aforementioned heating film control circuit and heating film control system include a first heating circuit and a second heating circuit. Based on the first heating control signal and the second heating control signal generated by the main control circuit, the first heating circuit and the second heating circuit can be accurately controlled to alternately provide the heating film to be controlled with a first working current and a second working current in opposite directions. Based on this, by alternately switching the current direction, the problem of electromigration of metal ions in the heating film conductor caused by the use of a fixed unidirectional current in the prior art is avoided, which leads to electromigration failure and seriously affects the service life of the heating film. The service life of the heating film is effectively extended. Attached Figure Description

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is a schematic diagram of the overall structure of the heating film control circuit in one embodiment;

[0040] Figure 2 This is a schematic diagram of the overall structure of the heating film control circuit in another embodiment;

[0041] Figure 3 This is a schematic diagram of the heating film control circuit in a specific embodiment.

[0042] Explanation of reference numerals in the attached figures:

[0043] 100, First heating circuit; 200, Second heating circuit; 300, Heating film to be controlled; 110, First switching circuit; 120, Second switching circuit; 130, Third switching circuit; 140, Fourth switching circuit. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0045] As described in the background section, current heating films suffer from a short lifespan. Research has found that the main reason for this short lifespan is that heating films typically use unidirectional current for heating. This unidirectional current causes electromigration of metal ions in the heating film conductor, leading to electromigration failure and severely impacting the film's lifespan. Therefore, this application aims to provide a heating film control circuit to solve the aforementioned technical problems, extend the lifespan of the heating film, and ensure that the heating film achieves a longer lifespan and more stable performance in various applications.

[0046] In one embodiment, such as Figure 1 As shown, Figure 1 This is a schematic diagram of the overall structure of a heating film control circuit in one embodiment; the heating film control circuit includes a first heating circuit 100 and a second heating circuit 200; wherein, the first heating circuit 100 is provided with a first control terminal; and the second heating circuit 200 is provided with a second control terminal;

[0047] The control terminal of the first heating circuit 100 is used to connect to the first control terminal CURR_P of the main control circuit and receive the first heating control signal generated by the main control circuit; the first heating circuit 100 is used to connect in series with the heating film 300 to be controlled, and to start or stop providing the first working current to the heating film 300 to be controlled according to the first heating control signal.

[0048] The control terminal of the second heating circuit 200 is used to connect to the second control terminal CURR_N of the main control circuit and receive the second heating control signal generated by the main control circuit; the second heating circuit 200 is used to connect in series with the heating film 300 to be controlled, and to start or stop providing the second operating current to the heating film 300 to be controlled according to the second heating control signal.

[0049] When the heating film control circuit is in operation, it alternately provides a first working current and a second working current to the heating film 300 to be controlled, with the direction of the first working current being opposite to that of the second working current.

[0050] The main control circuit includes at least a main controller; the main controller may be, but is not limited to, a microcontroller unit (MCU) or a system-on-a-chip (SOC); the main control circuit is used to generate corresponding first heating control signals and second heating control signals according to actual heating requirements. It should be noted that actual heating requirements may include, but are not limited to, current switching frequency, total heating time, etc., which are not specifically limited here. It is understood that, based on actual heating requirements, the main control circuit can accurately generate the first heating control signal and the second heating control signal, and then, based on the first heating control signal and the second heating control signal, can accurately control the state of the first heating circuit 100 and the second heating circuit 200 to alternately provide the heating film 300 to be controlled with a first operating current and a second operating current in opposite directions.

[0051] The control terminal of the first heating circuit 100 is used to receive a first heating control signal generated by the main control circuit according to the actual heating demand; the state of the first heating control signal includes an enabled state and a closed state; the state of the first heating circuit 100 includes a conducting state and a closed state.

[0052] For example, when the first heating control signal is enabled, the first heating circuit 100 is turned on, and a first operating current is supplied to the heating film 300 to be controlled; when the first heating control signal is turned off, the first heating circuit 100 is turned off, and the first operating current is stopped from being supplied to the heating film 300 to be controlled. The specific value of the first operating current needs to be set according to the performance of the heating film 300 to be controlled, and is not specifically limited here.

[0053] The control terminal of the second heating circuit 200 is used to receive a second heating control signal generated by the main control circuit according to the actual heating demand; the state of the second control signal includes an enabled state and a closed state; the state of the second heating circuit 200 includes a conducting state and a closed state.

[0054] For example, when the second heating control signal is enabled, the second heating circuit 200 is turned on, and a second operating current is supplied to the heating film 300 to be controlled; when the second heating control signal is turned off, the second heating circuit 200 is turned off, and the supply of the second operating current to the heating film 300 to be controlled stops. The specific value of the second operating current needs to be set according to the performance of the heating film 300 to be controlled, and is not specifically limited here. The direction of the second operating current is opposite to the direction of the first operating circuit.

[0055] In an exemplary embodiment, taking the heating film control circuit in operation as an example, according to the actual heating requirements, when the main control circuit generates a first heating control signal in an enabled state and a second heating control signal in a disabled state, the first heating circuit 100 is controlled to be in a conducting state by the first heating control signal, and a first operating current is provided to the heating film 300 to be controlled; at the same time, the second heating circuit 200 is controlled to be in a disabled state by the second heating control signal. Since the second heating circuit 200 is in a disabled state, no second operating current is generated. Furthermore, when the duration of the first operating current meets the current switching frequency, the main control circuit switches the state of the first heating control signal from the enabled state to the off state, and switches the state of the second heating control signal from the off state to the enabled state. At this time, the first heating circuit 100 is controlled to be in the off state by the first heating control signal, stopping the supply of the first operating current to the heating film 300 to be controlled; at the same time, the second heating circuit 200 switches from the off state to the on state, and begins to supply the second operating current to the heating film 300 to be controlled. This cycle continues, with the first and second operating currents in opposite directions alternately supplied to the heating film 300 to be controlled according to the current switching frequency, until the preset heating stop condition is met. The preset heating stop condition needs to be set according to the actual heating requirements, and is not specifically limited here.

[0056] In this embodiment, based on the first heating control signal and the second heating control signal generated by the main control circuit, the first heating circuit 100 and the second heating circuit 200 can be accurately controlled to alternately provide the heating film 300 to be controlled with the first working current and the second working current in opposite directions. Based on this, by alternately switching the current direction, the problem of electromigration of metal ions in the conductor of the heating film caused by the use of a fixed unidirectional current in the prior art can be effectively avoided, which leads to electromigration failure and seriously affects the service life of the heating film, thus effectively extending the service life of the heating film.

[0057] In one embodiment, such as Figure 2 As shown, Figure 2 This is a schematic diagram of the overall structure of the heating film control circuit in another embodiment; the first heating circuit 100 includes a first switching circuit 110 and a second switching circuit 120;

[0058] The first terminal of the first switching circuit 110 is used to connect to the first control terminal CURR_P of the main control circuit, the second terminal of the first switching circuit 110 is used to connect to the first power supply VCC1, and the third terminal of the first switching circuit 110 is used to connect to the first terminal of the heating film 300 to be controlled; the first switching circuit 110 is used to switch the on / off state according to the first heating control signal.

[0059] The first terminal of the second switching circuit 120 is connected to the first terminal of the first switching circuit 110, the second terminal of the second switching circuit 120 is used to connect to the second terminal of the heating film 300 to be controlled, and the third terminal of the second switching circuit 120 is grounded; the second switching circuit 120 is used to switch the on / off state according to the first heating control signal.

[0060] The first switching circuit 110 has a conducting characteristic; the state of the first switching circuit 110 includes a conducting state and a turning-off state; the second switching circuit 120 has a conducting characteristic; the state of the second switching circuit 120 includes a conducting state and a turning-off state; for example, when the first heating control signal is in an enabled state, both the first switching circuit 110 and the second switching circuit 120 are controlled to be in a conducting state; when the first heating control signal is in a turned-off state, both the first switching circuit 110 and the second switching circuit 120 are controlled to be in a turned-off state.

[0061] It should be noted that when the first heating control signal is in the enabled or disabled state, the level of the first heating control signal needs to be set according to the actual control requirements and the performance of the heating film control circuit, and no specific limitation is made here; for example, when the first heating control signal is in the enabled state, the first heating control signal is a low level signal; when the first heating control signal is in the disabled state, the first heating control signal is a high level signal.

[0062] The first power supply VCC1 is used to provide a first operating current to the heating film 300 to be controlled when both the first switching circuit 110 and the second switching circuit 120 are in the on state. It should be noted that the specific voltage value of the first power supply VCC1 needs to be set according to the performance of the heating film 300 to be controlled, and is not specifically limited here.

[0063] For example, when the first heating control signal is enabled, both the first switching circuit 110 and the second switching circuit 120 are turned on. At this time, the first power supply VCC1 flows through the first switching circuit 110, the heating film 300 to be controlled, and the second switching circuit 120, providing the first operating current to the heating film 300 to be controlled. When the first heating control signal is off, both the first switching circuit 110 and the second switching circuit 120 are turned off. At this time, the circuit of the first heating circuit 100 is cut off, and the first operating current to be supplied to the heating film 300 to be controlled stops.

[0064] In this embodiment, based on the first heating control signal, the on / off states of the first switching circuit 110 and the second switching circuit 120 can be accurately controlled, thereby ensuring the stability and reliability of the heating process according to the on / off states of the first switching circuit 110 and the second switching circuit 120.

[0065] In one embodiment, see Figure 3 , Figure 3 This is a schematic diagram of the heating film control circuit in a specific embodiment; the first switching circuit 110 includes a first switching transistor Q1, a first resistor R1, and a first diode D1;

[0066] The first terminal of the first switch Q1 is connected to the first control terminal CURR_P of the main control circuit via the first resistor R1, the second terminal of the first switch Q1 is connected to the first power supply VCC1, and the third terminal of the first switch Q1 is connected to the positive terminal of the first diode D1.

[0067] The negative terminal of the first diode D1 is used to connect to the first end of the heating film 300 to be controlled.

[0068] Wherein, the first switch Q1 is a MOSFET; the first switch Q1 has conduction characteristics; the state of the first switch Q1 includes an on state and an off state; in an exemplary embodiment, when the first heating control signal is in the enable state, the first switch Q1 is controlled to be in the on state; when the first heating control signal is in the off state, the first switch Q1 is controlled to be in the off state.

[0069] The resistance value of the first resistor R1 needs to be set according to the performance of the first switching circuit 110, and is not specifically limited here. The first diode D1 has unidirectional conduction characteristics and is used to protect the first switching transistor Q1 from being broken down by reverse voltage. The first power supply VCC1 is a DC power supply; the specific voltage value of the first power supply VCC1 needs to be set according to the performance of the heating film 300 to be controlled, and is not specifically limited here. For example, the voltage of the first power supply VCC1 can be 12V.

[0070] It should be noted that in this embodiment, the heating film 300 to be controlled is equivalent to a resistor.

[0071] In an exemplary embodiment, the first switch Q1 is a PMOS transistor, the first terminal of the first switch Q1 is the gate of the PMOS transistor, the second terminal of the first switch Q1 is the source of the PMOS transistor, and the third terminal of the first switch Q1 is the drain of the PMOS transistor; it is assumed that when the first heating control signal is in the enabled state, the first heating control signal is a low-level signal; when the first heating control signal is in the disabled state, the first heating control signal is a high-level signal. When the first heating control signal is enabled (i.e., low level), the first switch Q1 (PMOS transistor) is turned on. At this time, the second and third terminals of the first switch Q1 are connected, meaning the drain and source of the PMOS transistor are connected. The first power supply VCC1 flows to the heating film 300 to be controlled through the first switch Q1 (PMOS transistor) and the first diode D1. When the first heating control signal is off (i.e., high level), the first switch Q1 (PMOS transistor) is turned off. At this time, the second and third terminals of the first switch Q1 are disconnected, meaning the drain and source of the PMOS transistor are disconnected. The first power supply VCC1 cannot flow through the first switch Q1.

[0072] In this embodiment, based on the first heating control signal, the first switching transistor Q1 can be accurately turned on or off, laying the foundation for accurate and reliable control of the heating process of the heating film 300 to be controlled; based on the first diode D1, the problem of the first switching transistor Q1 being broken down by reverse voltage can be avoided, improving the safety of the first switching circuit 110, and thus ensuring the reliability of the heating film control circuit.

[0073] In one embodiment, see Figure 3 The second switching circuit 120 includes a second switching transistor Q2, a second resistor R2, a second diode D2, and a first logic circuit U1;

[0074] One end of the first logic circuit U1 is connected to the connection point of the first control terminal CURR_P and the first resistor R1 of the main control circuit, and the other end of the first logic circuit U1 is connected to the first terminal of the second switch Q2 via the second resistor R2.

[0075] The second terminal of the second switch Q2 is connected to the negative terminal of the second diode D2, and the third terminal of the second switch Q2 is grounded.

[0076] The positive terminal of the second diode D2 is used to connect to the second end of the heating film 300 to be controlled.

[0077] The first logic circuit U1 is used to convert the first heating control signal. In an exemplary embodiment, the first logic circuit U1 is an inverter used to flip the first heating control signal. For example, when the first heating control signal is a low-level signal, the first logic circuit U1, i.e., the inverter, flips the first heating control signal, i.e., the low-level signal, to obtain a high-level signal.

[0078] Wherein, the second switch Q2 is a MOSFET; the second switch Q2 has conduction characteristics; the state of the second switch Q2 includes an on state and an off state; in an exemplary embodiment, when the first heating control signal is in an enabled state, after the first logic circuit U1 performs signal conversion on the first heating control signal, it can control the second switch Q2 to be in an on state; when the first heating control signal is in an off state, after the first logic circuit U1 performs signal conversion on the first heating control signal, it can control the second switch Q2 to be in an off state.

[0079] The value of the second resistor R2 needs to be set according to the performance of the second switching circuit 120, and is not specifically limited here. The second diode D2 has unidirectional conduction characteristics and is used to protect the second switching transistor Q2 and prevent it from being broken down by reverse voltage.

[0080] In an exemplary embodiment, the first switch Q1 is a PMOS transistor, the second switch Q2 is an NMOS transistor, and the first logic circuit U1 is an inverter; the first terminal of the second switch Q2 is the gate of the NMOS transistor, the second terminal of the second switch Q2 is the drain of the NMOS transistor, and the third terminal of the second switch Q2 is the source of the NMOS transistor.

[0081] Assuming the first heating control signal is enabled (low level) and disabled (high level), when it is enabled (low level), it controls the first switch Q1 (PMOS transistor) to conduct. Simultaneously, the first heating control signal is converted to a high level by the first logic circuit U1 (inverter), controlling the second switch Q2 (NMOS transistor) to conduct. The second and third terminals of the second switch Q2 are connected, meaning the drain and source of the NMOS transistor are connected. At this time, the first power supply VCC1 flows through the first switch Q1 (PMOS transistor), the first diode D1, the controlled heating film 300, the second diode D2, and the second switch Q2 (NMOS transistor), providing the first operating current to the controlled heating film 300.

[0082] When the first heating control signal is in the off state, i.e., the first heating control signal is a high-level signal, the first switch Q1, i.e., the PMOS transistor, is controlled to be in the off state. At the same time, the first heating control signal is converted into a low-level signal by the first logic circuit U1, i.e., the inverter, thereby controlling the second switch Q2, i.e., the NMOS transistor, to be in the off state. The second terminal and the third terminal of the second switch Q2 are disconnected, i.e., the drain and source of the NMOS transistor are disconnected. At this time, the first operating current is stopped from being supplied to the heating film 300 to be controlled.

[0083] In this embodiment, based on the first heating control signal and the first logic circuit U1, the second switch Q2 can be accurately turned on or off, laying the foundation for accurate and reliable control of the heating process of the heating film 300 to be controlled; based on the second diode D2, the problem of the second switch Q2 being broken down by reverse voltage can be avoided, improving the safety of the second switch circuit 120, and thus ensuring the reliability of the heating film control circuit.

[0084] In one embodiment, see Figure 2 The second heating circuit 200 includes a third switching circuit 210 and a fourth switching circuit 220;

[0085] The first terminal of the third switching circuit 210 is used to connect to the second control terminal CURR_N of the main control circuit; the second terminal of the third switching circuit 210 is used to connect to the second power supply VCC2; and the third terminal of the third switching circuit 210 is used to connect to the connection point between the second terminal of the heating film 300 to be controlled and the second terminal of the second switching circuit 120. The third switching circuit 210 is used to switch the on / off state according to the second heating control signal.

[0086] The first end of the fourth switch circuit 220 is connected to the first end of the third switch circuit 210. The second end of the fourth switch circuit 220 is used to connect to the connection point between the first end of the heating film 300 to be controlled and the third end of the first switch circuit 110. The third end of the fourth switch circuit 220 is grounded. The fourth switch circuit 220 is used to switch the on / off state according to the second heating control signal.

[0087] The third switching circuit 210 has a conduction characteristic; the state of the third switching circuit 210 includes a conduction state and a turn-off state; for example, when the second heating control signal is in the enable state, the third switching circuit 210 is controlled to be in the conduction state; when the second heating control signal is in the turn-off state, the third switching circuit 210 is controlled to be in the turn-off state.

[0088] The fourth switching circuit 220 has a conduction characteristic; the state of the fourth switching circuit 220 includes a conduction state and a turn-off state; for example, when the second heating control signal is in the enable state, the fourth switching circuit 220 is controlled to be in the conduction state; when the second heating control signal is in the turn-off state, the fourth switching circuit 220 is controlled to be in the turn-off state.

[0089] It should be noted that when the second heating control signal is in the enabled or disabled state, the level of the second heating control signal needs to be set according to the actual control requirements and the performance of the heating film control circuit, and no specific limitation is made here; for example, when the second heating control signal is in the enabled state, the second heating control signal is a low level signal; when the second heating control signal is in the disabled state, the second heating control signal is a high level signal.

[0090] The second power supply VCC2 is used to provide a second operating current to the heating film 300 to be controlled when both the third switching circuit 210 and the fourth switching circuit 220 are in the on state. It should be noted that the specific voltage value of the second power supply VCC2 needs to be set according to the performance of the heating film 300 to be controlled, and is not specifically limited here.

[0091] For example, when the second heating control signal is enabled, both the third switch circuit 210 and the fourth switch circuit 220 are turned on. At this time, the second power supply VCC2 flows through the third switch circuit 210, the heating film 300 to be controlled, and the fourth switch circuit 220 to provide the second operating current to the heating film 300 to be controlled. When the second heating control signal is off, both the third switch circuit 210 and the fourth switch circuit 220 are turned off. At this time, the circuit of the second heating circuit 200 is cut off, and the second operating current to be supplied to the heating film 300 to be controlled stops.

[0092] In this embodiment, based on the second heating control signal, the on / off states of the third switch circuit 210 and the fourth switch circuit 220 can be accurately controlled, thereby ensuring the stability and reliability of the heating process according to the on / off states of the third switch circuit 210 and the fourth switch circuit 220.

[0093] In one embodiment, see Figure 3 The third switching circuit 210 includes a third switching transistor Q3, a third resistor R3, and a third diode D3;

[0094] The first terminal of the third switch Q3 is used to connect to the second control terminal CURR_N of the main control circuit via the third resistor R3. The second terminal of the third switch Q3 is used to connect to the second power supply VCC2. The third terminal of the third switch Q3 is connected to the positive terminal of the third diode D3.

[0095] The negative terminal of the third diode D3 is used to connect to the second end of the heating film 300 to be controlled.

[0096] Wherein, the third switch Q3 is a MOSFET; the third switch Q3 has conduction characteristics; the state of the third switch Q3 includes a conduction state and a turn-off state; in an exemplary embodiment, when the second heating control signal is in the enable state, the third switch Q3 is controlled to be in the conduction state; when the second heating control signal is in the off state, the third switch Q3 is controlled to be in the turn-off state.

[0097] The resistance value of the third resistor R3 needs to be set according to the performance of the third switching circuit 210, and is not specifically limited here. The third diode D3 has unidirectional conduction characteristics and is used to protect the third switching transistor Q3, preventing Q3 from being broken down by reverse voltage. The second power supply VCC2 is a DC power supply; the specific voltage value of the second power supply VCC2 needs to be set according to the performance of the heating film 300 to be controlled, and is not specifically limited here. For example, the voltage of the second power supply VCC2 can be 12V.

[0098] In an exemplary embodiment, the third switch Q3 is a PMOS transistor. The first terminal of the third switch Q3 is the gate of the PMOS transistor, the second terminal of the third switch Q3 is the source of the PMOS transistor, and the third terminal of the third switch Q3 is the drain of the PMOS transistor. It is assumed that when the second heating control signal is in the enabled state, the second heating control signal is a low-level signal; when the second heating control signal is in the disabled state, the second heating control signal is a high-level signal. When the second heating control signal is enabled (i.e., low level), the third switch Q3 (PMOS transistor) is turned on. At this time, the second and third terminals of the third switch Q3 are connected, meaning the drain and source of the PMOS transistor are connected. The second power supply VCC2 flows through the third switch Q3 (PMOS transistor) and the third diode D3 to the heating film 300 to be controlled. When the second heating control signal is off (i.e., high level), the third switch Q3 (PMOS transistor) is turned off. At this time, the second and third terminals of the third switch Q3 are disconnected, meaning the drain and source of the PMOS transistor are disconnected. The second power supply VCC2 cannot flow through the third switch Q3.

[0099] In this embodiment, based on the second heating control signal, the third switch Q3 can be accurately turned on or off, laying the foundation for accurate and reliable control of the heating process of the heating film 300 to be controlled; based on the third diode D3, the problem of the third switch Q3 being broken down by reverse voltage can be avoided, improving the safety of the third switch circuit 210, and thus ensuring the reliability of the heating film control circuit.

[0100] In one embodiment, see Figure 3 The fourth switching circuit 220 includes a fourth switching transistor Q4, a fourth resistor R4, a fourth diode D4, and a second logic circuit U2;

[0101] One end of the second logic circuit U2 is connected to the connection point of the second control terminal CURR_N and the third resistor R3 of the main control circuit, and the other end of the second logic circuit is connected to the first end of the fourth switch Q4 via the fourth resistor R4.

[0102] The second terminal of the fourth switch Q4 is connected to the negative terminal of the fourth diode D4, and the third terminal of the fourth switch Q4 is grounded.

[0103] The positive terminal of the fourth diode D4 is used to connect to the first end of the heating film 300 to be controlled.

[0104] The second logic circuit U2 is used to convert the second heating control signal. In an exemplary embodiment, the second logic circuit U2 is an inverter used to flip the second heating control signal. For example, when the second heating control signal is a low-level signal, the second logic circuit U2, i.e., the inverter, flips the second heating control signal, i.e., the low-level signal, to obtain a high-level signal.

[0105] Wherein, the fourth switch Q4 is a MOSFET; the fourth switch Q4 has conduction characteristics; the state of the fourth switch Q4 includes an on state and an off state; in an exemplary embodiment, when the second heating control signal is in the enabled state, after the second logic circuit U2 performs signal conversion on the second heating control signal, it can control the fourth switch Q4 to be in the on state; when the second heating control signal is in the off state, after the second logic circuit U2 performs signal conversion on the second heating control signal, it can control the fourth switch Q4 to be in the off state.

[0106] The resistance value of the fourth resistor R4 needs to be set according to the performance of the fourth switch circuit 220, and is not specifically limited here. The fourth diode D4 has unidirectional conduction characteristics and is used to protect the fourth switch Q4 from being broken down by reverse voltage.

[0107] In an exemplary embodiment, the third switch Q3 is a PMOS transistor, the fourth switch Q4 is an NMOS transistor, and the second logic circuit U2 is an inverter; the first terminal of the fourth switch Q4 is the gate of the NMOS transistor, the second terminal of the fourth switch Q4 is the drain of the NMOS transistor, and the third terminal of the fourth switch Q4 is the source of the NMOS transistor.

[0108] Assuming the second heating control signal is enabled (low level) and disabled (high level), when it is enabled (low level), it controls the third switch Q3 (PMOS transistor) to conduct. Simultaneously, the second heating control signal is converted to a high level by the second logic circuit U2 (inverter), controlling the fourth switch Q4 (NMOS transistor) to conduct. The second and third terminals of the fourth switch Q4 are connected, meaning the drain and source of the NMOS transistor are connected. At this time, the second power supply VCC2 flows through the third switch Q3 (PMOS transistor), the third diode D3, the controlled heating film 300, the fourth diode D4, and the fourth switch Q4 (NMOS transistor), providing the second operating current to the controlled heating film 300.

[0109] When the second heating control signal is in the off state, i.e., when the second heating control signal is a high-level signal, the third switch Q3, i.e., the PMOS transistor, is controlled to be in the off state. At the same time, the second heating control signal is converted into a low-level signal by the second logic circuit U2, i.e., the inverter, thereby controlling the fourth switch Q4, i.e., the NMOS transistor, to be in the off state. The second terminal of the fourth switch Q4 is disconnected from the third terminal, i.e., the drain and source of the NMOS transistor are disconnected. At this time, the second operating current is stopped from being provided to the heating film 300 to be controlled.

[0110] In this embodiment, based on the second heating control signal and the second logic circuit U2, the fourth switch Q4 can be accurately turned on or off, laying the foundation for accurate and reliable control of the heating process of the heating film 300 to be controlled; based on the fourth diode D4, the problem of the fourth switch Q4 being broken down by reverse voltage can be avoided, improving the safety of the fourth switch circuit 220, and thus ensuring the reliability of the heating film control circuit.

[0111] In one specific embodiment, with Figure 3Taking this as an example, the main control circuit generates corresponding first and second heating control signals through the first control terminal CURR_P and the second control terminal CURR_N, realizing the alternating activation of the first heating circuit 100 and the second heating circuit 200, thereby alternately providing the controlled heating film 300 with a first operating current and a second operating current in opposite directions. Specifically, when the first heating control signal is enabled and the second heating control signal is disabled, the first heating circuit 100 is turned on and the second heating circuit 200 is turned off. At this time, the first power supply VCC1 provides the controlled heating film 300 with a first operating current. When the first heating control signal is disabled and the second heating control signal is enabled, the first heating circuit 100 is turned off and the second heating circuit 200 is turned on. At this time, the second power supply VCC2 provides the controlled heating film 300 with a second operating current. This cycle repeats according to the current switching frequency until the preset heating stop condition is met.

[0112] The aforementioned heating film control circuit, based on the first and second heating control signals generated by the main control circuit, can accurately control the first heating circuit 100 and the second heating circuit 200 to alternately provide the heating film to be controlled with a first working current and a second working current in opposite directions. Based on this, by alternately switching the current direction, it can effectively avoid the problem in the prior art where the use of a fixed unidirectional current causes electromigration of metal ions in the heating film conductor, leading to electromigration failure and seriously affecting the service life of the heating film, thus effectively extending the service life of the heating film. Based on the first heating control signal, it can accurately control the on / off states of the first switching circuit 110 and the second switching circuit 120, thereby ensuring the stability and reliability of the heating process. Based on the second heating control signal, it can accurately control the on / off states of the third switching circuit 210 and the fourth switching circuit 220, thereby ensuring the stability and reliability of the heating process.

[0113] In one embodiment, the heating film control system includes a main control circuit, a heating film control circuit in any of the above embodiments, a heating film to be controlled, a first power supply, and a second power supply.

[0114] The heating film control circuit is connected to the main control circuit, the heating film to be controlled, the first power supply, and the second power supply.

[0115] The specific circuit structure and working principle of the heating film control circuit have been described in the above embodiments and will not be repeated here.

[0116] The main control circuit includes at least a main controller; the main controller may be, but is not limited to, an MCU or a SOC; the main control circuit is used to generate corresponding first heating control signals and second heating control signals according to the actual heating requirements. It should be noted that the actual heating requirements may include, but are not limited to, the current switching frequency and the total heating time; the current switching frequency, for example, is 1 hour / time, and is not specifically limited here.

[0117] The specific voltage values ​​of the first and second power supplies need to be set according to the performance of the heating film control circuit and the performance of the heating film to be controlled, and are not specifically limited here.

[0118] In this embodiment, based on the heating film control system, bidirectional working current can be provided to the heating film to be controlled by alternately switching the current direction. This avoids the problem in the prior art where the use of a fixed unidirectional current causes electromigration of metal ions in the heating film conductor, leading to electromigration failure and seriously affecting the service life of the heating film, thus effectively extending the service life of the heating film.

[0119] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0120] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0121] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0122] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0123] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0124] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0125] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0126] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A heating film control circuit, characterized in that, The heating film control circuit includes a first heating circuit and a second heating circuit; wherein, the first heating circuit is provided with a first control terminal; and the second heating circuit is provided with a second control terminal; The control terminal of the first heating circuit is used to connect to the first control terminal of the main control circuit and receive the first heating control signal generated by the main control circuit; the first heating circuit is used to connect in series with the heating film to be controlled and to start or stop providing a first working current to the heating film to be controlled according to the first heating control signal. The control terminal of the second heating circuit is used to connect to the second control terminal of the main control circuit and receive the second heating control signal generated by the main control circuit; the second heating circuit is used to connect in series with the heating film to be controlled and to start or stop providing a second operating current to the heating film to be controlled according to the second heating control signal. When the heating film control circuit is in operation, it alternately provides the first working current and the second working current to the heating film to be controlled, wherein the direction of the first working current is opposite to the direction of the second working current.

2. The heating film control circuit according to claim 1, characterized in that, The first heating circuit includes a first switching circuit and a second switching circuit; The first terminal of the first switching circuit is used to connect to the first control terminal of the main control circuit, the second terminal of the first switching circuit is used to connect to the first power supply, and the third terminal of the first switching circuit is used to connect to the first terminal of the heating film to be controlled; the first switching circuit is used to switch the on / off state according to the first heating control signal. The first terminal of the second switching circuit is connected to the first terminal of the first switching circuit, the second terminal of the second switching circuit is used to connect to the second terminal of the heating film to be controlled, and the third terminal of the second switching circuit is grounded; the second switching circuit is used to switch the on / off state according to the first heating control signal.

3. The heating film control circuit according to claim 2, characterized in that, The first switching circuit includes a first switching transistor, a first resistor, and a first diode; The first terminal of the first switching transistor is used to connect to the first control terminal of the main control circuit via the first resistor, the second terminal of the first switching transistor is used to connect to the first power supply, and the third terminal of the first switching transistor is connected to the positive terminal of the first diode. The negative terminal of the first diode is used to connect to the first end of the heating film to be controlled.

4. The heating film control circuit according to claim 3, characterized in that, The second switching circuit includes a second switching transistor, a second resistor, a second diode, and a first logic circuit; One end of the first logic circuit is connected to the connection point of the first control terminal and the first resistor of the main control circuit, and the other end of the first logic circuit is connected to the first terminal of the second switching transistor via the second resistor. The second terminal of the second switching transistor is connected to the negative terminal of the second diode, and the third terminal of the second switching transistor is grounded. The positive terminal of the second diode is used to connect to the second end of the heating film to be controlled.

5. The heating film control circuit according to claim 4, characterized in that, The first logic circuit is an inverter; The first switching transistor is a PMOS transistor; The second switch is an NMOS transistor.

6. The heating film control circuit according to claim 2, characterized in that, The second heating circuit includes a third switching circuit and a fourth switching circuit; The first terminal of the third switching circuit is used to connect to the second control terminal of the main control circuit, the second terminal of the third switching circuit is used to connect to the second power supply, and the third terminal of the third switching circuit is used to connect to the connection point between the second terminal of the heating film to be controlled and the second terminal of the second switching circuit; the third switching circuit is used to switch the on / off state according to the second heating control signal. The first terminal of the fourth switching circuit is connected to the first terminal of the third switching circuit, the second terminal of the fourth switching circuit is used to connect to the connection point between the first terminal of the heating film to be controlled and the third terminal of the first switching circuit, and the third terminal of the fourth switching circuit is grounded; the fourth switching circuit is used to switch the on / off state according to the second heating control signal.

7. The heating film control circuit according to claim 6, characterized in that, The third switching circuit includes a third switching transistor, a third resistor, and a third diode; The first terminal of the third switch is used to connect to the second control terminal of the main control circuit via the third resistor, the second terminal of the third switch is used to connect to the second power supply, and the third terminal of the third switch is connected to the positive terminal of the third diode. The negative terminal of the third diode is used to connect to the second end of the heating film to be controlled.

8. The heating film control circuit according to claim 7, characterized in that, The fourth switching circuit includes a fourth switching transistor, a fourth resistor, a fourth diode, and a second logic circuit. One end of the second logic circuit is connected to the connection point of the second control terminal and the third resistor of the main control circuit, and the other end of the second logic circuit is connected to the first terminal of the fourth switch via the fourth resistor. The second terminal of the fourth switching transistor is connected to the negative terminal of the fourth diode, and the third terminal of the fourth switching transistor is grounded. The positive terminal of the fourth diode is used to connect to the first end of the heating film to be controlled.

9. The heating film control circuit according to claim 8, characterized in that, The second logic circuit is an inverter; The third switch is a PMOS transistor; The fourth switch is an NMOS transistor.

10. A heating film control system, characterized in that, The heating film control system includes a main control circuit, a heating film control circuit according to any one of claims 1 to 9, a heating film to be controlled, a first power supply, and a second power supply. The heating film control circuit is connected to the main control circuit, the heating film to be controlled, the first power supply, and the second power supply, respectively.

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