A multi-mode series-parallel interlocked heating circuit

Abstract

The application relates to a multi-mode series-parallel interlocking heating circuit, which comprises a battery power supply module, an adapter power supply module, a parallel driving module, a series driving module and a driving control module. The power output end of the battery power supply module is connected to the parallel driving module, the power output end of the adapter power supply module is connected to the series driving module, the enable signal output end of the driving control module is connected to the controlled end of the parallel driving module and the controlled end of the series driving module respectively, when a mode switching signal is received, an interlocking control operation is performed based on the on-off state of the parallel driving module and the series driving module, and the parallel driving module or the series driving module is driven to be turned on according to the mode switching signal. In the two modes of the battery and the adapter, the stability of the MCH heating body in the heating process can be ensured, and in the power supply switching process, the circuit overload, device damage and potential safety hazards caused by double-path superimposed power supply are avoided.

Description

Technical Field

[0001] This invention relates to the technical field of series-parallel interlocking heating circuits, and in particular to a multi-mode series-parallel interlocking heating circuit. Background Technology

[0002] Currently, with the widespread use of personal care devices and portable small heating products (such as hair straighteners, curling irons, and portable soldering irons), users have raised higher requirements for the heating performance and user experience of such products. First, while the single battery power mode is portable, the heating power is limited due to the limited battery capacity and instantaneous discharge capability, making it difficult to achieve rapid heating. This results in long waiting times and low heating efficiency during use. Second, while the single adapter power mode can provide higher heating power to meet the needs of rapid heating and high-load use, it loses portability, requiring users to rely on external power sources, which limits the application scenarios.

[0003] Therefore, existing circuits connect the battery and adapter simultaneously, but this easily leads to situations where the battery and external power supply simultaneously power the load. This disordered and superimposed power output not only causes circuit overload and damages components, but also poses serious safety hazards such as electric shock and overheating. Summary of the Invention

[0004] To address the safety hazard that arises from connecting the battery and adapter simultaneously in existing circuits, this application provides a multi-mode series-parallel interlocking heating circuit.

[0005] A multi-mode series-parallel interlocking heating circuit includes: a heating module comprising at least two MCH heating elements, the circuit comprising a battery power supply module, an adapter power supply module, a parallel drive module, a series drive module and a drive control module, and a power output module for connecting the two MCH heating elements;

[0006] The power output terminal of the battery power supply module is connected to the parallel drive module, and the power output terminal of the parallel drive module is connected to the parallel voltage node of the power output module to provide a parallel drive voltage for the MCH heating element in battery power supply mode.

[0007] The power output terminal of the adapter power supply module is connected to the series drive module, and the power output terminal of the series drive module is connected to the series voltage node of the power output module to provide a series drive voltage for each of the MCH heating elements in the adapter power supply mode.

[0008] The enable signal output terminal of the drive control module is connected to the controlled terminal of the parallel drive module and the controlled terminal of the series drive module respectively. When the drive control module receives the mode switching signal, it performs an interlock control operation based on the on / off state of the parallel drive module and the series drive module, and drives the parallel drive module or the series drive module to conduct according to the mode switching signal.

[0009] By adopting the above technical solution, and by simultaneously setting up a battery power supply module, an adapter power supply module, a parallel drive module, a series drive module, a drive control module, and a power output module, it is possible to flexibly switch between battery mode and adapter mode, and ensure that the heating element can obtain a stable operating voltage in both modes, thereby simultaneously meeting the requirements for portability and high power, and avoiding the safety risks caused by power supply conflicts.

[0010] Preferably, the parallel drive module includes MOSFET Q10, MOSFET Q12, resistor R11, and MOSFET Q13. The power output terminal of the battery power supply module is connected to the first conducting terminal of MOSFET Q10. The second conducting terminal of MOSFET Q10 is connected to the first conducting terminal of MOSFET Q12. The second conducting terminal of MOSFET Q12 is connected to the parallel voltage node of the power output module. The common node between the second conducting terminal of MOSFET Q10 and the first conducting terminal of MOSFET Q12 is connected to the first terminal of resistor R11. The second terminal of resistor R11, the controlled terminal of MOSFET Q10, and the controlled terminal of MOSFET Q12 are all connected to the enable signal output terminal of the drive control module. The common node between the power output terminal of the series drive module and the series voltage node of the power output module is connected to the first conducting terminal of MOSFET Q13. The second conducting terminal of MOSFET Q13 is grounded.

[0011] By adopting the above technical solution, the parallel drive module design utilizes a combination of MOSFETs and resistors to achieve parallel output control of the battery power supply end, enabling the voltage in battery mode to be efficiently transferred to both ends of the heating element. This achieves a more stable heating effect under limited battery capacity conditions and reduces the problem of reduced heating efficiency caused by current fluctuations.

[0012] Preferably, the series drive module includes MOSFET Q9, MOSFET Q11, and resistor R12. The power output terminal of the adapter power supply module is connected to the first conducting terminal of MOSFET Q9, the second conducting terminal of MOSFET Q9 is connected to the first conducting terminal of MOSFET Q11, the second conducting terminal of MOSFET Q11 is connected to the series voltage node of the power output module, the common node between the second conducting terminal of MOSFET Q9 and the first conducting terminal of MOSFET Q11 is connected to the first terminal of resistor R12, and the second terminal of resistor R12, the controlled terminal of MOSFET Q9, and the controlled terminal of MOSFET Q11 are all connected to the enable signal output terminal of the drive control module.

[0013] By adopting the above technical solution, in the design of the series drive module, the voltage in the adapter power supply mode can be applied to multiple heating elements in series through the connection structure of two MOSFETs and resistors, thereby making full use of the high power capability of the external power supply and ensuring performance stability under rapid heating and high load working conditions.

[0014] Preferably, the multi-mode series-parallel interlocked heating circuit further includes a main control module. The drive control module includes a switching unit and an interlocking unit. The first enable output terminal of the switching unit is connected to the controlled terminal of the parallel drive module to drive the parallel drive module to turn on or off. The second enable output terminal of the switching unit is connected to the controlled terminal of the series drive module to drive the series drive module to turn on or off. The switching signal input terminal of the switching unit is connected to the switching signal output terminal of the main control module to receive the mode switching signal. The interlocking unit is used to control the switching unit to perform corresponding interlocking control operations.

[0015] By adopting the above technical solution, with the introduction of the drive control module, the circuit can achieve precise control through the cooperation of the switching unit and the interlocking unit when it receives the mode switching signal. This not only ensures smooth switching between different modes, but also prevents two drives from being turned on at the same time, thereby improving the overall safety and reliability of operation.

[0016] Preferably, the switching signal output terminal of the main control module includes at least a first switching output port and a second switching output port. The switching unit includes transistors Q15 and Q16. The first conducting terminal of transistor Q15 serves as the first enable output terminal of the switching unit, and the second conducting terminal of transistor Q15 is grounded. The controlled terminal of transistor Q15 is connected to the first switching output port. The first conducting terminal of transistor Q16 serves as the second enable output terminal of the switching unit, and the second conducting terminal of transistor Q16 is grounded. The controlled terminal of transistor Q16 is connected to the second switching output port. A common node between the controlled terminal of transistor Q15 and the first switching output port is defined as a first interlock node. The first interlock node is connected to the controlled terminal of MOSFET Q13.

[0017] By adopting the above technical solution, with the cooperation of the main control module, switching unit, and interlocking unit, and through the combination of transistors and MOSFETs, independent drive control of different power supply modes is realized, and interlocking protection can be achieved through level pull-down during mode switching, thereby effectively eliminating the short circuit and overload hazards caused by dual power supply concurrency.

[0018] Preferably, the interlocking unit includes transistor Q14 and transistor Q17;

[0019] The controlled terminal of transistor Q14 is connected to the second switching output port. The common node between the first interlock node and the controlled terminal of MOSFET Q13 is connected to the first conducting terminal of transistor Q14. The second conducting terminal of transistor Q14 is grounded. This is used to control the level of the controlled terminal of MOSFET Q13 and the level of the controlled terminal of transistor Q15 to be pulled down to ground when driving the series drive module to conduct, thereby causing MOSFET Q13 and transistor Q15 to disconnect.

[0020] The controlled terminal of transistor Q17 is connected to the first switching output port. A common node between the controlled terminal of transistor Q16 and the second switching output port is defined as the second interlock node. The second interlock node is connected to the first conducting terminal of transistor Q17. The second conducting terminal of transistor Q17 is grounded, so as to control the level of the controlled terminal of transistor Q16 to be pulled down to ground when driving the parallel driving module to conduct, thereby turning off transistor Q16.

[0021] By adopting the above technical solution, in the specific circuit structure of the interlocking unit, through the logic relationship between the transistors, when one mode is turned on, the other control signal will be automatically pulled low, thereby ensuring that the two drives will not be in working state at the same time, so that the power supply switching process has a forced interlocking function, which greatly improves the safety of circuit operation.

[0022] Preferably, the power output module includes a terminal block JP4 and a terminal block JP5. The first end of the terminal block JP4 serves as the series voltage node of the power output module. The second end of the terminal block JP4 is connected to the first end of the terminal block JP5. The second end of the terminal block JP5 is grounded. The common node between the second end of the terminal block JP4 and the first end of the terminal block JP5 serves as the parallel voltage node of the power output module.

[0023] By adopting the above technical solution, the series voltage node and the parallel voltage node are clearly distinguished in the power output module through the special connection method of the wiring terminals, so that the heating element under different power supply modes can obtain reasonable voltage distribution, thereby ensuring the stability of the heating effect under different working conditions.

[0024] Preferably, the common node between the second conducting terminal of the MOS transistor Q13 and the second terminal of the terminal JP5 is connected to the first terminal of the fuse JP6, and the second terminal of the fuse JP6 is grounded.

[0025] By adopting the above technical solution, the structure of connecting a fuse in series between the power output terminal and ground enables hardware-level physical circuit breaking protection when the current rises abnormally, thereby preventing the device from overheating or being damaged, and further improving the system's safety protection capability.

[0026] Preferably, the second terminal of the fuse JP6 is connected to the first terminal of the resistor R19, the second terminal of the resistor R19 is grounded, the common node between the first terminal of the resistor R19 and the second terminal of the fuse JP6 is connected to the first terminal of the resistor R17, and the second terminal of the resistor R17 outputs a corresponding sampling signal.

[0027] By adopting the above technical solution, a resistor sampling network is added to the circuit after the fuse, which enables the generation of a corresponding sampling signal under overcurrent conditions and feeds it back to the main control circuit. This combines software detection and hardware protection to form a dual protection mechanism, improving the circuit's response speed and accuracy to abnormal conditions.

[0028] Preferably, the adapter power supply module includes a terminal block TYPEC1 and a first charging management unit, and the battery power supply module includes a second charging management unit and a protection unit. The power input terminal of the terminal block TYPEC1 is connected to a power source, the power output terminal of the terminal block TYPEC1 is connected to the power input terminal of the first charging management unit, the power output terminal of the first charging management unit is connected to the power input terminal of the series drive module, the power output terminal of the first charging management unit is connected to the power input terminal of the second charging management unit, the power output terminal of the second charging management unit is connected to the power input terminal of the parallel drive module, and the protection unit is connected between the first charging management unit and the second charging management unit to provide reverse connection protection when the polarity of the power output terminal of the first charging management unit is reversed or when there is an abnormal overvoltage.

[0029] By adopting the above technical solution, a two-stage charging management and protection unit is introduced between the adapter end and the battery end. This allows for reasonable distribution and protection of voltage and current when an external power source is input. It also enables timely blocking in case of reverse polarity connection or overvoltage, preventing damage to the battery and drive circuit caused by abnormalities. This ensures the stability and safety of the entire system under dual power supply access.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] This application incorporates both a battery-powered module and an adapter-powered module in its circuit structure, connected to parallel and series drive modules respectively. This allows for a stable voltage supply to multiple MCH heating elements in parallel during battery mode, ensuring normal heating performance in portable applications. In adapter mode, power is supplied to the heating elements in series, achieving high power output to meet rapid heating requirements. Furthermore, by implementing interlock control based on the on / off states of the two drive paths upon receiving a mode switching signal, the simultaneous conduction of the battery and adapter power supply paths is fundamentally prevented, ensuring independence and safety between different power supply modes. In both battery and adapter modes, the MCH heating elements receive nearly identical operating voltages, ensuring heating stability. During power switching, circuit overload, component damage, and potential safety hazards caused by dual-path superposition of power supplies are avoided. Thus, while balancing portability and high performance, the circuit operates safely and reliably. Attached Figure Description

[0032] Figure 1 This is a flowchart of a multi-mode series-parallel interlocked heating circuit according to one embodiment of this application.

[0033] Figure 2This is a partial circuit structure diagram of the parallel drive module, series drive module, drive control module and power output module in a multi-mode series-parallel interlocked heating circuit according to an embodiment of this application.

[0034] Figure 3 This is a partial circuit structure diagram of the battery power supply module and the adapter power supply module in a multi-mode series-parallel interlocked heating circuit according to an embodiment of this application. Detailed Implementation

[0035] The present application will be further described in detail below with reference to the accompanying drawings.

[0036] In one embodiment, such as Figure 1 As shown, this application discloses a multi-mode series-parallel interlocking heating circuit. The multi-mode series-parallel interlocking heating circuit includes: applied to a heating module including at least two MCH heating elements, the circuit includes a battery power supply module, an adapter power supply module, a parallel drive module, a series drive module and a drive control module, and a power output module for connecting the two MCH heating elements.

[0037] The power output terminal of the battery-powered module is connected to the parallel drive module, and the power output terminal of the parallel drive module is connected to the parallel voltage node of the power output module to provide parallel drive voltage for the MCH heating element in battery-powered mode.

[0038] The power output terminal of the adapter power supply module is connected to the series drive module, and the power output terminal of the series drive module is connected to the series voltage node of the power output module to provide series drive voltage for each MCH heating element in adapter power supply mode.

[0039] The enable signal output terminal of the drive control module is connected to the controlled terminal of the parallel drive module and the controlled terminal of the series drive module respectively. When the drive control module receives the mode switching signal, it performs interlock control operation based on the on / off state of the parallel drive module and the series drive module, and drives the parallel drive module or the series drive module to conduct according to the mode switching signal.

[0040] In this embodiment, the power output terminal of the battery-powered module is first connected to the parallel drive module, and the power output terminal of the parallel drive module is further connected to the parallel voltage node set in the power output module. Thus, in battery mode, the battery voltage can be directly transmitted to the input terminals of each MCH heating element through the parallel drive module, ensuring that multiple heating elements receive essentially the same voltage when powered by the battery, achieving stable heating output. The power output terminal of the adapter-powered module is connected to the series drive module, and the power output terminal of the series drive module is connected to the series voltage node of the power output module. In this way, in adapter mode, the voltage of the external power supply is sequentially applied to multiple MCH heating elements through the series drive module, enabling the heating elements to rapidly heat up under high power conditions and maintain high-load heating. The enable signal output of the drive control module is connected to the controlled terminals of both the parallel and series drive modules. Upon receiving a mode switching signal, the drive control module controls the parallel or series drive module to conduct according to its current enable state. Simultaneously, its internal interlocking mechanism ensures that when one mode is active, the controlled terminal level of the other mode is pulled down, thus avoiding the overload risk caused by simultaneous conduction of the parallel and series paths. The power output module acts as a bridge between the entire circuit and the heating element. By setting different voltage nodes, it ensures a reasonable voltage distribution for the heating element in different power supply modes, achieving low-voltage parallel drive in battery mode and high-voltage series drive in adapter mode. This allows for flexible switching between battery and adapter modes and ensures the stability of the heating element and the safety of circuit operation in different working modes.

[0041] Furthermore, such as Figure 2 As shown, the parallel drive module includes MOSFETs Q10 and Q12, resistor R11, and MOSFET Q13. The power output terminal of the battery-powered module is connected to the first conducting terminal of MOSFET Q10. The second conducting terminal of MOSFET Q10 is connected to the first conducting terminal of MOSFET Q12. The second conducting terminal of MOSFET Q12 is connected to the parallel voltage node of the power output module. The common node between the second conducting terminal of MOSFET Q10 and the first conducting terminal of MOSFET Q12 is connected to the first terminal of resistor R11. The second terminal of resistor R11, the controlled terminal of MOSFET Q10, and the controlled terminal of MOSFET Q12 are all connected to the enable signal output terminal of the drive control module. The common node between the power output terminal of the series drive module and the series voltage node of the power output module is connected to the first conducting terminal of MOSFET Q13. The second conducting terminal of MOSFET Q13 is grounded.

[0042] In this embodiment, the parallel drive channel consists of a back-to-back controlled switch composed of MOSFETs Q10 and Q12 and resistor R11. The entire channel is uniformly driven by the enable signal output of the drive control module. When the enable signal output is high, the controlled terminals of MOSFETs Q10 and Q12 simultaneously receive gate drive, forming a sufficient gate-source voltage relative to their common intermediate node. The first conducting terminal of MOSFET Q10 conducts to its second conducting terminal, and then continuously conducts through the first conducting terminal of MOSFET Q12 to its second conducting terminal, allowing the voltage of the battery power supply module to be transmitted to the parallel voltage node of the power output module with low loss, thereby providing a stable and consistent voltage to the multiple MCH heating elements connected in parallel. When the enable signal output is low or in an disabled state, resistor R11 is connected between the enable signal output terminal and the second conducting terminal of MOSFET Q10. The first conducting terminals of MOSFET Q12 are equivalent to the gate-source discharge paths of two switching devices, which can promptly release the gate charge and pull the gate-source voltages of both devices back to near zero, ensuring that MOSFETs Q10 and Q12 are turned off quickly and reliably. At the same time, since MOSFETs Q10 and Q12 are connected back-to-back in series, their body diodes are isolated in both directions, which can effectively block the reverse current from the parallel voltage node of the power output module to the battery power supply module and the cross-current in other power supply modes, avoiding disordered superposition between different power supply channels. In addition, resistor R11 feeds back the transient potential of the intermediate common node to the enable signal output terminal, forming a self-stabilizing network of gate potential together with the gate drive. This can suppress the misleading turn-on caused by the Miller effect when a voltage step occurs in the parallel voltage node or the battery power supply module, limit the steepness of the switching edge and reduce the surge, thereby improving the stability of the parallel voltage node of the power output module and the power supply consistency of the MCH heating element during battery mode conduction, and improving isolation reliability and system safety during turn-off and mode switching.

[0043] Furthermore, such as Figure 2 As shown, the series drive module includes MOSFET Q9, MOSFET Q11, and resistor R12. The power output terminal of the adapter power supply module is connected to the first conducting terminal of MOSFET Q9. The second conducting terminal of MOSFET Q9 is connected to the first conducting terminal of MOSFET Q11. The second conducting terminal of MOSFET Q11 is connected to the series voltage node of the power output module. The common node between the second conducting terminal of MOSFET Q9 and the first conducting terminal of MOSFET Q11 is connected to the first terminal of resistor R12. The second terminal of resistor R12, the controlled terminal of MOSFET Q9, and the controlled terminal of MOSFET Q11 are all connected to the enable signal output terminal of the drive control module.

[0044] In this embodiment, the series power supply channel consists of MOSFETs Q9 and Q11 and resistor R12 forming a controlled series switch, which is uniformly driven by the enable signal output of the drive control module. When the enable signal output of the drive control module outputs an effective level, the controlled terminals of MOSFETs Q9 and Q11 simultaneously receive gate drive, causing the two transistors to form low-resistance conduction paths in the directions from the first conducting terminal to the second conducting terminal of MOSFET Q9 and from the first conducting terminal to the second conducting terminal of MOSFET Q11, respectively. The power output of the adapter power supply module is continuously supplied to the series voltage node of the power output module via MOSFET Q9 → the common intermediate node of the two transistors → MOSFET Q11, forming a series power supply loop of "heating element - heating element" on the load side. In this operating state, the higher available power on the adapter side is applied to multiple MCH heating elements in series. The loop current is equal, and the voltage division is adaptively distributed according to the resistance value. This ensures both the overall rapid heating capability and the suppression of overcurrent bias caused by individual MCH differences, thereby improving the stability and consistency under high load scenarios. When the enable signal output of the dynamic control module is deactivated, resistor R12 establishes a discharge path between the common intermediate node of the two transistors and the gate drive side, quickly releasing the gate charge of MOSFETs Q9 and Q11 and pulling the gate-source voltage difference between the two transistors back to near zero, achieving reliable turn-off. Simultaneously, because MOSFETs Q9 and Q11 are structurally equivalent to reverse-connected body diodes in a "back-to-back" relationship, voltage transitions from either the adapter power supply module side or the series voltage node side of the power output module will not form a reverse path through the body diodes during the turn-off state. It effectively blocks backflow and cross-current during mode switching; in addition, resistor R12 and the input capacitors of the two power devices together form a gate buffer network, which suppresses misleading turn-on caused by Miller injection when the adapter power supply module is powered on, dropped, or subjected to load step, limits the steepness of turn-on / turn-off edges and reduces surges, thereby reducing the switching losses and thermal shock of MOSFETs Q9 and Q11. Combined with the system-level interlocking strategy, it can ensure that the series channel and the parallel channel will not be turned on at the same time, thus achieving high power, low loss, controllable transients and high isolation series drive in adapter mode.

[0045] Furthermore, such as Figure 2 As shown, a multi-mode series-parallel interlocked heating circuit further includes a main control module. The drive control module includes a switching unit and an interlocking unit. The first enable output terminal of the switching unit is connected to the controlled terminal of the parallel drive module to drive the parallel drive module to turn on or off. The second enable output terminal of the switching unit is connected to the controlled terminal of the series drive module to drive the series drive module to turn on or off. The switching signal input terminal of the switching unit is connected to the switching signal output terminal of the main control module to receive the mode switching signal. The interlocking unit is used to control the switching unit to perform the corresponding interlocking control operation.

[0046] In this embodiment, a main control module is further provided in addition to the parallel drive module and the series drive module. Within the drive control module, the functions of the switching unit and the interlocking unit are clearly distinguished. The main control module, as the logic core of the system, is responsible for generating mode switching signals under different working scenarios. These switching signals are transmitted from the main control module's switching signal output terminal to the switching signal input terminal of the switching unit, where the switching unit performs specific level conversion and drive amplification. The switching unit has two independent enable output terminals. The first enable output terminal is directly connected to the controlled terminal of the parallel drive module. When it receives a parallel mode command from the main control module, it outputs a valid level to drive the parallel drive module to conduct, or removes the level to disconnect it when it needs to exit the parallel mode. The second enable output terminal is connected to the controlled terminal of the series drive module. When it receives a series mode command from the main control module, it outputs a valid level to drive the series drive module to conduct, or removes the level to remain off when exiting the series mode. Due to the potential concurrent risks of dual-drive, the interlocking unit plays a core protective role throughout the process. When the main control module switches one path to the conducting state, the interlocking unit will automatically monitor and forcibly pull down the control level of the other enable terminal, thereby preventing both paths from being turned on at the same time. This forced interlocking mechanism not only ensures the exclusivity of the switching process, but also avoids the dangerous situation of battery power supply and adapter power supply being superimposed in the circuit at the same time. This makes the multi-mode series-parallel interlocking heating circuit have safe and reliable control characteristics while achieving flexible function switching.

[0047] Furthermore, such as Figure 2 As shown, the switching signal output terminal of the main control module includes at least a first switching output port and a second switching output port. The switching unit includes transistors Q15 and Q16. The first conducting terminal of transistor Q15 serves as the first enable output terminal of the switching unit, and the second conducting terminal of transistor Q15 is grounded. The controlled terminal of transistor Q15 is connected to the first switching output port. The first conducting terminal of transistor Q16 serves as the second enable output terminal of the switching unit, and the second conducting terminal of transistor Q16 is grounded. The controlled terminal of transistor Q16 is connected to the second switching output port. A common node between the controlled terminal of transistor Q15 and the first switching output port is defined as the first interlock node. The first interlock node is connected to the controlled terminal of MOSFET Q13.

[0048] In this embodiment, the main control module provides mode commands to the switching unit through the first and second switching output ports respectively. The switching unit uses built-in transistors Q15 and Q16 to complete the pull-down drive conversion from small signal to enable current. Simultaneously, it uses MOSFET Q13 to perform hardware clamping and interlocking on key nodes of the series channel: when the first switching output port enters an active state, its level is directly applied to the controlled terminal of transistor Q15 and is equidistant from the first interlocked node, thus turning on transistor Q15. This allows the first conducting terminal of transistor Q15 (serving as the first enable output terminal of the switching unit) to form a low-impedance path to ground, thereby providing... The controlled terminal of the parallel drive module provides a stable pull-down drive, which, together with the pull-up network, enables reliable conduction of the parallel channel. At the same time, the first interlock node also serves as the controlled terminal drive source for MOSFET Q13, allowing MOSFET Q13 to obtain sufficient gate-source voltage and conduct. The first conducting terminal of MOSFET Q13 is close to the common node between the power output terminal of the series drive module and the series voltage node of the power output module. After conduction, MOSFET Q13 quickly pulls this common node to ground potential, which is equivalent to a hardware short-circuit clamp and parasitic charge discharge channel for the output side of the series channel. On the one hand, it quickly clears the series side node and the common voltage node during mode switching. The residual charge on the input capacitor of the device suppresses misleading conduction and cross-conduction induced by the Miller effect. On the other hand, during the operation of the parallel channel, it firmly locks the key nodes of the series channel at a low potential, blocking backflow and cross-current caused by the body diode or parasitic path, and avoiding the superposition of power from the two paths. Conversely, when the second switching output port enters the active state, its level is applied to the controlled terminal of transistor Q16. After transistor Q16 is turned on, the first conducting terminal of transistor Q16 (as the second enable output terminal of the switching unit) forms a low-impedance path to ground, providing a reliable pull-down enable drive for the series drive module, and under the cooperation of the interlocking unit, the first The interlocked node remains at a low potential, keeping MOSFET Q13 off and not clamping the output node of the series channel. This achieves a hardware-level interlocked link that "forces clamping the series when parallel conduction is on and releases the clamp when series conduction is on." With the help of the open-collector pull-down output configuration of transistors Q15 and Q16 and the rapid discharge / clamping of the common node by MOSFET Q13, this solution can achieve deterministic level boundaries, smaller inrush current, and lower false trigger probability when switching between the two modes. At the same time, it ensures that the parallel and series power paths do not overlap at any time, thereby improving the safety of the whole machine and the controllability of mode switching.

[0049] Furthermore, such as Figure 2 As shown, the interlock unit includes transistors Q14 and Q17;

[0050] The controlled terminal of transistor Q14 is connected to the second switching output port. The common node between the first interlock node and the controlled terminal of MOSFET Q13 is connected to the first conducting terminal of transistor Q14. The second conducting terminal of transistor Q14 is grounded. This is used to control the level of the controlled terminal of MOSFET Q13 and the level of the controlled terminal of transistor Q15 to be pulled down to ground when the series drive module is turned on, thereby turning off MOSFET Q13 and transistor Q15.

[0051] The controlled terminal of transistor Q17 is connected to the first switching output port. A common node between the controlled terminal of transistor Q16 and the second switching output port is defined as the second interlock node. The second interlock node is connected to the first conducting terminal of transistor Q17. The second conducting terminal of transistor Q17 is grounded so as to control the level of the controlled terminal of transistor Q16 to be pulled down to ground when the parallel driving module is turned on, thereby turning off transistor Q16.

[0052] In this embodiment, the interlocking logic consists of two symmetrical pull-down suppression channels formed by transistors Q14 and Q17, directly driven by the second switching output port and the first switching output port, respectively, and acting on the first and second interlocking nodes to implement hardware-level "preemption-masking" of the opposite channel when mode selection occurs. When the second switching output port is set to an active level to prepare to drive the series channel, the controlled terminal of transistor Q16 is given an enable bias, and simultaneously the controlled terminal of transistor Q14 also receives a source control signal, causing transistor Q14 to quickly turn on. The first conducting terminal of transistor Q14 is connected to the common node between the first interlocking node and the controlled terminal of MOSFET Q13. After turning on, transistor Q14 forces the common node to be pulled down to near ground potential, thereby rapidly discharging and maintaining the controlled terminal of MOSFET Q13 at a low potential, allowing MOSFET Q13 to reliably turn off and disconnecting the output terminal and power supply of the series drive module. The clamping of the common node between the series voltage nodes of the output module, on the other hand, synchronously pulls the first interlock node low, so that the controlled terminal of transistor Q15 is pressed to a low potential and immediately cut off, avoiding the parallel channel from being enabled through transistor Q15; this short-path discharge of "second switching output port → transistor Q14 → first interlock node / controlled terminal of MOS transistor Q13" not only quickly releases the gate / base charge during level flip and power-on step, suppressing misleading conduction and overlap caused by Miller coupling, but also gives the series channel hardware priority in timing, ensuring that the parallel channel is in a passively disabled state during the effective period of series mode. In the reverse scenario, when the first switching output port is set to an active level to prepare for driving the parallel channel, the controlled terminal of transistor Q15 is biased to enable. Simultaneously, the controlled terminal of transistor Q17 also receives a source control signal, turning on transistor Q17. The first conducting terminal of transistor Q17 is connected to the second interlock node, which is the common node between the controlled terminal of transistor Q16 and the second switching output port. After being turned on, transistor Q17 pulls the second interlock node down to near ground potential, directly suppressing the controlled terminal level of transistor Q16 and reliably turning off transistor Q16, thereby blocking the enable link of the series channel. At the same time, the first switching output port raises the level of the first interlock node through transistor Q15 and drives the controlled terminal of MOSFET Q13 through the first interlock node, turning on MOSFET Q13 to provide ground clamping and parasitic charge discharge channel for the common node on the output side of the series drive module, further eliminating any residual conduction risk of the series channel in parallel mode.Therefore, through the cross-pull-down network formed by "transistor Q14 - first interlock node - MOSFET Q13" and "transistor Q17 - second interlock node - transistor Q16", regardless of whether the first or second switching output port is high, the opposite control node can be pulled low at the hardware level in real time, forming a mutually exclusive non-overlapping conduction relationship. This mechanism provides the shortest discharge path and effective level boundary control during mode switching and voltage transition, significantly reducing overlapping current, surge and thermal shock, and avoiding overload and reverse flow caused by the simultaneous conduction of two power paths. This improves the transient controllability and system-level safety and reliability of the multi-mode series-parallel interlocked heating circuit when switching between parallel mode and series mode.

[0053] Furthermore, such as Figure 2 As shown, the power output module includes terminal JP4 and terminal JP5. The first end of terminal JP4 serves as the series voltage node of the power output module. The second end of terminal JP4 is connected to the first end of terminal JP5. The second end of terminal JP5 is grounded. The common node between the second end of terminal JP4 and the first end of terminal JP5 serves as the parallel voltage node of the power output module.

[0054] The common node between the second conducting terminal of MOSFET Q13 and the second terminal of terminal JP5 is connected to the first terminal of fuse JP6, and the second terminal of fuse JP6 is grounded.

[0055] The second terminal of fuse JP6 is connected to the first terminal of resistor R19. The second terminal of resistor R19 is grounded. The common node between the first terminal of resistor R19 and the second terminal of fuse JP6 is connected to the first terminal of resistor R17. The second terminal of resistor R17 outputs the corresponding sampling signal.

[0056] In this embodiment, the power output module serves as the interface between the drive channel and the heating module, correctly distributing the power supply voltage to the MCH heating element under different modes while providing safety protection and detection. The first end of terminal JP4 is defined as a series voltage node. When the series drive module is on, this node directly carries the voltage output by the adapter power supply module and transmits it to the heating module, ensuring that the two MCH heating elements operate in series in high-power mode. The second end of terminal JP4 is electrically connected to the first end of terminal JP5. The common node between them is defined as a parallel voltage node. When the parallel drive module is on, the voltage output by the battery power supply module is simultaneously distributed to the two MCH heating elements via this common node, ensuring low-voltage parallel drive in battery mode and maintaining consistent voltage across each heating element. The second end of terminal JP5 is directly grounded, thus JP4 and JP5 constitute a complete power supply path.

[0057] To add safety protection at the output, the first terminal of fuse JP6 is connected in series between the second conducting terminal of MOSFET Q13 and the second terminal of terminal JP5. When the load current exceeds a preset limit, the fuse JP6 can quickly blow, physically cutting off the grounding loop and preventing damage to circuit components or overheating of the heating module due to overload, thus providing first-level hardware protection. At the second terminal of fuse JP6, the first terminal of resistor R19 is also connected. The second terminal of resistor R19 is fixedly grounded. During normal operation, this resistor provides discharge and steady-state resistance support for the ground loop, and provides a stable reference potential at the moment fuse JP6 blows, preventing the output terminal from being floating and causing uncertain fluctuations. Simultaneously, the common node between the second terminal of fuse JP6 and the first terminal of resistor R19 is also connected to the first terminal of resistor R17. The second terminal of resistor R17 serves as a sampling port, outputting a corresponding sampling signal that reflects the current flowing through fuse JP6 and the grounding loop in real time. By processing the sampled signal in the main control module, it is possible to determine in advance at the software level whether there is an overcurrent trend, so that current limiting or shutdown measures can be taken before the fuse JP6 blows.

[0058] Furthermore, such as Figure 3 As shown, the adapter power supply module includes a terminal block TYPEC1 and a first charging management unit, while the battery power supply module includes a second charging management unit and a protection unit. The power input terminal of the terminal block TYPEC1 is connected to a power source, and the power output terminal of the terminal block TYPEC1 is connected to the power input terminal of the first charging management unit. The power output terminal of the first charging management unit is connected to the power input terminal of the series drive module, the power output terminal of the first charging management unit is connected to the power input terminal of the second charging management unit, and the power output terminal of the second charging management unit is connected to the power input terminal of the parallel drive module. A protection unit is connected between the first charging management unit and the second charging management unit to provide reverse connection protection when the polarity of the power output terminal of the first charging management unit is reversed or when there is an abnormal overvoltage.

[0059] In this embodiment, the first charging management unit includes MOSFETs Q21, Q22, and Q28; the second charging management unit includes a charging management chip U1, MOSFETs Q24, Q25, Q26, and Q29; and the protection unit includes MOSFETs Q18, Q19, and Q20. The input channel on the adapter side is physically connected to an external power source via terminal block TYPEC1. The power input terminal of terminal block TYPEC1 is directly coupled to the external adapter, enabling the system to receive a stable external power supply voltage. The power output terminal of terminal block TYPEC1 is connected to the power input terminal of the first charging management unit. The first charging management unit performs voltage regulation, overcurrent detection, and power matching in this path, and can stably output electrical energy according to the set parameters when external power is supplied. The power output terminal of the first charging management unit is directly connected to the power input terminal of the series drive module, ensuring a stable high-power input for the series drive module in external adapter mode, thus providing energy for the series connection of multiple MCH heating elements. Simultaneously, the power output terminal of the first charging management unit is also connected to the power input terminal of the second charging management unit, enabling the second charging management unit to further convert and distribute this energy to the battery-powered module, charging the battery when needed, or providing a suitable power input to the parallel drive module in battery mode. The power output terminal of the second charging management unit is connected to the power input terminal of the parallel drive module, ensuring a stable voltage for the parallel drive module in portable battery mode, thereby maintaining a balanced heating effect when multiple MCH heating elements are connected in parallel. To further enhance circuit safety, a dedicated protection unit is installed between the first and second charging management units. When the power output of the first charging management unit experiences reverse polarity or abnormal overvoltage, the protection unit immediately activates, isolating the reverse voltage or overvoltage signal to prevent abnormal power from being transmitted to the second charging management unit and subsequent circuits. This prevents battery overcharging, drive module overvoltage breakdown, or overall damage due to abnormal input. Through the coordination of the above structure, the TYPEC1 terminal block, the first charging management unit, the second charging management unit, and the protection unit form a complete energy management link from the external power supply to the battery and drive module. This ensures flexible switching between multiple modes while also providing multiple functions such as charging management, energy distribution, and abnormal protection. Therefore, in practical applications, the circuit can provide the high-power supply required for rapid heating while maintaining safety and reliability in portable mode.

[0060] In summary, the specific working principle is as follows:

[0061] This multi-mode series-parallel interlocked heating circuit uses two MCH heating elements as the load core. The battery power supply module and the adapter power supply module provide energy to the load through parallel drive module and series drive module, respectively. The power output module outputs the voltage nodes of different power supply modes to the load. The drive control module realizes the switching between the two modes and interlock protection through the switching unit and the interlock unit.

[0062] In battery-powered mode, the battery voltage at the BAT+ terminal is directly transmitted to the parallel voltage node between terminals JP4 and JP5 after being turned on by the parallel drive module composed of MOSFETs Q10 and Q12. This allows the two loads to obtain approximately the same voltage in parallel, thus ensuring stable heating output even with limited battery capacity. Resistor R11 serves to discharge the gate and stabilize the potential, ensuring that MOSFETs Q10 and Q12 are reliably turned off when not enabled, preventing battery voltage from entering other channels.

[0063] In adapter power supply mode, the adapter voltage at the VBUS terminal is transmitted sequentially to the series voltage node of terminal JP4 after being turned on by the series drive module composed of MOSFETs Q9 and Q11. This distributes the voltage to the two loads, forming a series working state, which fully utilizes the high power advantage of the external power supply to achieve rapid heating and stable heating under high load. Resistor R12 also serves to discharge the gate and suppress mis-conduction, ensuring that MOSFETs Q9 and Q11 are reliably turned off in the disabled state.

[0064] To ensure that different modes do not conduct simultaneously, the drive control module implements interlock protection through a switching unit and an interlocking unit. The switching unit consists of transistors Q15 and Q16 and a MOSFET Q13. The first conducting terminal of transistor Q15 serves as the first enable output terminal, used to drive the parallel drive module; the first conducting terminal of transistor Q16 serves as the second enable output terminal, used to drive the series drive module; and MOSFET Q13 is connected between the output of the series drive module and ground, providing clamping and discharge paths when the parallel mode is on, to ensure that the series path is locked. The interlock unit consists of transistors Q14 and Q17. When the series mode is enabled, transistor Q14 pulls down the first interlock node and the controlled terminal of MOSFET Q13, causing MOSFET Q13 to turn off, and simultaneously cutting off the control of transistor Q15, preventing the parallel path from conducting. When the parallel mode is enabled, transistor Q17 pulls down the second interlock node, causing transistor Q16 to turn off, preventing the series path from being enabled. Through the cross-control of Q14 and Q17, the two modes always maintain a mutually exclusive relationship.

[0065] The power output module consists of terminals JP4 and JP5. The first terminal of JP4 serves as a series voltage node, and the second terminal of JP4 is connected to the first terminal of JP5 to form a parallel voltage node. The second terminal of JP5 is grounded, allowing for appropriate load connection in both modes. A fuse JP6 is connected in series between the second conducting terminal of MOSFET Q13 and the second terminal of JP5 for overcurrent protection. The second terminal of fuse JP6 is then connected to resistors R19 and R17. R19 is a current-sensing resistor; the voltage across it can be used to detect the current flowing through the load. R17 further outputs the sampling signal to the control system for software-level current monitoring and protection.

[0066] In addition, the adapter power supply module includes a terminal block TYPEC1 and a first charging management unit, while the battery power supply module includes a second charging management unit and a protection unit. TYPEC1 establishes the physical connection with the external adapter. The first charging management unit regulates the voltage and outputs it to the series drive module, while simultaneously supplying power to the second charging management unit, which in turn provides input voltage to the parallel drive module and also handles battery charging. A protection unit is installed between the first and second charging management units. When the external power supply experiences reverse polarity or overvoltage, this protection unit immediately activates to prevent the abnormality from being transmitted to the battery and drive module, ensuring the safety of the overall circuit.

[0067] In summary, this circuit achieves automatic switching between battery mode and adapter mode through the differentiated design of parallel and series drive modules; it achieves mutual exclusion and reliability of power supply modes through the coordination of the switching unit and the interlocking unit; it achieves current detection and overcurrent protection through the combination of the power output module, fuse, and current sensing resistor; and it achieves power management and safety assurance through dual charging management units and protection units, thereby ensuring stable heating and safe and reliable operation in both portable and high-performance usage scenarios.

[0068] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A multi-mode series-parallel interlocked heating circuit, characterized by, The multi-mode series-parallel interlocking heating circuit comprises: being applied to a heating module comprising at least two MCH heating bodies, the circuit comprising a battery power supply module, an adapter power supply module, a parallel driving module, a series driving module and a driving control module, and a power output module for connecting the two MCH heating bodies; The power output end of the battery power supply module is connected to the parallel driving module, and the power output end of the parallel driving module is connected to the parallel voltage node of the power output module to provide parallel driving voltage for the MCH heating bodies in the battery power supply mode; The power output end of the adapter power supply module is connected to the series driving module, and the power output end of the series driving module is connected to the series voltage node of the power output module to provide series driving voltage for each MCH heating body in the adapter power supply mode; The enable signal output end of the driving control module is connected to the controlled end of the parallel driving module and the controlled end of the series driving module respectively, and the driving control module is used for performing interlocking control operation based on the on-off state of the parallel driving module and the series driving module when receiving a mode switching signal, and driving the parallel driving module or the series driving module to be turned on according to the mode switching signal.

2. A multi-mode series-parallel interlocking heating circuit according to claim 1, wherein, The parallel driving module comprises MOS tube Q10, MOS tube Q12, resistor R11 and MOS tube Q13, the power output end of the battery power supply module is connected to the first conduction end of the MOS tube Q10, the second conduction end of the MOS tube Q10 is connected to the first conduction end of the MOS tube Q12, the second conduction end of the MOS tube Q12 is connected to the parallel voltage node of the power output module, the common node between the second conduction end of the MOS tube Q10 and the first conduction end of the MOS tube Q12 is connected to the first end of the resistor R11, the second end of the resistor R11, the controlled end of the MOS tube Q10 and the controlled end of the MOS tube Q12 are all connected to the enable signal output end of the driving control module, and the common node between the power output end of the series driving module and the series voltage node of the power output module is connected to the first conduction end of the MOS tube Q13, and the second conduction end of the MOS tube Q13 is grounded.

3. A multi-mode series-parallel interlocking heating circuit according to claim 1, wherein, The series driving module comprises MOS tube Q9, MOS tube Q11 and resistor R12, the power output end of the adapter power supply module is connected to the first conduction end of the MOS tube Q9, the second conduction end of the MOS tube Q9 is connected to the first conduction end of the MOS tube Q11, the second conduction end of the MOS tube Q11 is connected to the series voltage node of the power output module, the common node between the second conduction end of the MOS tube Q9 and the first conduction end of the MOS tube Q11 is connected to the first end of the resistor R12, the second end of the resistor R12, the controlled end of the MOS tube Q9 and the controlled end of the MOS tube Q11 are all connected to the enable signal output end of the driving control module.

4. A multi-mode series-parallel interlocking heating circuit according to claim 2, wherein, The multi-mode series-parallel interlocking heating circuit further comprises a master control module, the drive control module comprises a switching unit and an interlocking unit, a first enable output end of the switching unit is connected with a controlled end of the parallel drive module, for driving the parallel drive module to turn on or turn off, a second enable output end of the switching unit is connected with a controlled end of the series drive module, for driving the series drive module to turn on or turn off, a switching signal input end of the switching unit is connected with a switching signal output end of the master control module, for receiving the mode switching signal, and the interlocking unit is used for controlling the switching unit to perform corresponding interlocking control operation.

5. A multi-mode series-parallel interlocking heating circuit according to claim 4, wherein, The switching signal output end of the master control module at least comprises a first switching output port and a second switching output port, the switching unit comprises a transistor Q15 and a transistor Q16, a first conduction end of the transistor Q15 serves as the first enable output end of the switching unit, a second conduction end of the transistor Q15 is grounded, a controlled end of the transistor Q15 is connected with the first switching output port, a first conduction end of the transistor Q16 serves as the second enable output end of the switching unit, a second conduction end of the transistor Q16 is grounded, and a controlled end of the transistor Q16 is connected with the second switching output port, a common node between the controlled end of the transistor Q15 and the first switching output port is determined as a first interlocking node, and the first interlocking node is connected with a controlled end of the MOS tube Q13.

6. A multi-mode series-parallel interlocking heating circuit according to claim 5, wherein, The interlocking unit comprises a transistor Q14 and a transistor Q17; the controlled end of the transistor Q14 is connected with the second switching output port, a common node between the first interlocking node and the controlled end of the MOS tube Q13 is connected with a first conduction end of the transistor Q14, a second conduction end of the transistor Q14 is grounded, for controlling the level of the controlled end of the MOS tube Q13 and the level of the controlled end of the transistor Q15 to be pulled down to the ground when the series drive module is driven to turn on, so as to turn off the MOS tube Q13 and the transistor Q15; the controlled end of the transistor Q17 is connected with the first switching output port, a common node between the controlled end of the transistor Q16 and the second switching output port is determined as a second interlocking node, the second interlocking node is connected with a first conduction end of the transistor Q17, and a second conduction end of the transistor Q17 is grounded, for controlling the level of the controlled end of the transistor Q16 to be pulled down to the ground when the parallel drive module is driven to turn on, so as to turn off the transistor Q16.

7. A multi-mode series-parallel interlocking heating circuit according to claim 2, wherein, The power output module comprises a terminal JP4 and a terminal JP5, a first end of the terminal JP4 is a series voltage node of the power output module, a second end of the terminal JP4 is connected with a first end of the terminal JP5, a second end of the terminal JP5 is grounded, and a common node between the second end of the terminal JP4 and the first end of the terminal JP5 is a parallel voltage node of the power output module.

8. A multi-mode series-parallel interlocking heating circuit according to claim 7, wherein, A first end of a fuse JP6 is connected with a common node between a second conductive end of the MOS tube Q13 and the second end of the terminal JP5, and a second end of the fuse JP6 is grounded.

9. A multi-mode series-parallel interlocking heating circuit according to claim 8, wherein, A first end of a resistor R19 is connected with the second end of the fuse JP6, a second end of the resistor R19 is grounded, a first end of a resistor R17 is connected with a common node between the first end of the resistor R19 and the second end of the fuse JP6, and a second end of the resistor R17 outputs a corresponding sampling signal.

10. A multi-mode series-parallel interlocking heating circuit according to claim 1, wherein, The adapter power supply module comprises a terminal TYPEC1 and a first charging management unit, the battery power supply module comprises a second charging management unit and a protection unit, a power input end of the terminal TYPEC1 is connected with a power supply, a power output end of the terminal TYPEC1 is connected with a power input end of the first charging management unit, a power output end of the first charging management unit is connected with a power input end of the series driving module, the power output end of the first charging management unit is connected with a power input end of the second charging management unit, a power output end of the second charging management unit is connected with a power input end of the parallel driving module, and the protection unit is connected between the first charging management unit and the second charging management unit, so as to provide reverse connection protection when the power output end of the first charging management unit is reversely connected or abnormally overvoltage.

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