Power supply module supporting wide voltage input and driving board card

Abstract

The utility model relates to a power supply module supporting wide voltage input and a driving board card, and belongs to the field of power electronic switch tube driving. The power supply module comprises a control circuit and a flyback power supply, the primary side of the flyback power supply is connected in series with a feedback resistor, and the secondary side is used for driving a switching tube; the control circuit comprises a sampling loop connected with the feedback resistor and the second triode, a third triode, a current source, a sampling resistor, a first comparison circuit and a logic driving circuit; the emitter of the third triode is connected with the feedback resistor; the second triode and the third triode form a mirror image constant current source circuit; the collector of the second triode is grounded through a current source; the collector of the third triode is grounded through a sampling resistor; the output end of the logic driving circuit is connected with the control end of the first switching tube; the logic driving circuit is connected with the sampling resistor; and the control circuit outputs PWM signals with different duty ratios according to the voltage at the two ends of the sampling resistor. The circuit is simple in structure and low in cost.

Description

Technical Field

[0001] This utility model relates to a power module and driver board that support wide voltage input, belonging to the field of power electronic switch tube driving. Background Technology

[0002] With the accelerated advancement of energy transition and digital transformation, the industrial and commercial energy storage market is experiencing rapid growth. Insulated-gate bipolar transistors (IGBTs) and silicon carbide metal-oxide-semiconductor field-effect transistors (MOSFETs), as core components in power electronic products, have seen their driving and protection technologies become a key research focus. Power devices such as IGBTs and MOSFETs typically operate at high frequencies and possess high-speed switching capabilities, requiring driver modules to drive them. As driving solutions continue to innovate, the quality of the driver module directly affects the system's efficiency, reliability, and safety.

[0003] As industrial and commercial energy storage products continue to be developed and diversified, the power supply voltages that different products can provide to the drive modules may be inconsistent. For example, some power supply voltages are +5V, some are +12V, some are +15V, some are +24V, and so on. When the voltage provided by the power supply deviates too much from the drive voltage required by the switching transistor, the switching transistor may be burned out. Therefore, there is an urgent need for a circuit that can be compatible with the power supply voltages output by various power supplies and convert the power supply voltage into the drive voltage required by the downstream switching transistor.

[0004] Chinese invention patent application CN119109328A discloses a voltage conversion circuit, meter, and control method for wide input voltage. The disclosed circuit includes a first-stage power conversion circuit that detects the voltage of the input bus. When the detected signal on the input bus is less than a set threshold voltage, the first-stage power conversion circuit operates; otherwise, it stops operating. A second-stage power conversion circuit receives the output voltage from the first-stage circuit and converts it to the desired output voltage. The set threshold voltage is determined based on the withstand voltage of the power transistor in the first-stage power conversion circuit. This technical solution allows for controllable withstand voltage of the main power switching transistor in the first-stage power conversion circuit, enabling the selection of medium- to low-voltage switching transistors, significantly reducing switching losses and costs, and improving system performance.

[0005] Although this solution can support a wide voltage input and convert the input voltage into the voltage required by the downstream load, it requires a two-stage power conversion circuit, which makes the circuit complex and costly. Utility Model Content

[0006] The purpose of this invention is to provide a power module and driver board that support wide voltage input, in order to solve the problems of complex circuits and high cost in the prior art.

[0007] To achieve the above objectives, the solution of this utility model includes:

[0008] This utility model provides a power supply module that supports a wide input voltage, including a flyback power supply for connecting a wide input voltage, wherein the primary side of the flyback power supply is connected in series with a feedback resistor, and the secondary side is used to drive a switching transistor.

[0009] The power module also includes control circuitry;

[0010] The control circuit includes a sampling circuit, a second transistor, a third transistor, a current source, a sampling resistor, a first comparator circuit, and a logic drive circuit.

[0011] The input terminal of the sampling circuit is connected to one end of the feedback resistor, and the output terminal is connected to the emitter of the second transistor; the emitter of the third transistor is connected to the other end of the feedback resistor.

[0012] The base of the second transistor is connected to the base of the third transistor; the collector of the second transistor is grounded through a current source.

[0013] The collector of the second transistor is also connected to the base of the second transistor;

[0014] The collector of the third transistor is grounded through a sampling resistor;

[0015] The output of the logic drive circuit is connected to the control terminal of the first switching transistor in the flyback power supply.

[0016] The logic driver circuit uses a sampling resistor to output a first PWM signal when the voltage across the sampling resistor is greater than a fixed voltage value, and to output a second PWM signal when the voltage across the sampling resistor is less than the fixed voltage value.

[0017] The duty cycle of the first PWM signal is smaller than that of the second PWM signal.

[0018] Furthermore, the logic driving circuit includes a first comparator, logic circuitry, and a PWM wave generator connected to the control terminal of the first switching transistor;

[0019] The sampling resistor is used to connect one end of the collector of the third transistor as a signal point to one input terminal of the first comparator circuit. The other input terminal of the first comparator circuit is used to connect a fixed voltage value. The output terminal of the first comparator circuit is used to connect to the input terminal of the logic circuit.

[0020] The output of the logic circuit is connected to the PWM wave generator to control the PWM wave generator to output the first PWM signal or the second PWM signal.

[0021] The first comparator circuit is used to output a first signal when the voltage at the signal point is greater than a fixed voltage value, and to output a second signal when the voltage is less than the fixed voltage value.

[0022] The logic circuit is used to generate a first logic signal based on a first signal and to generate a second logic signal based on a second signal;

[0023] The PWM wave generator is used to output a first PWM signal after receiving a first logic signal, and to output a second PWM signal after receiving a second logic signal.

[0024] Furthermore, the control circuit also includes a second comparator;

[0025] One input of the second comparator is used to connect to a preset operating voltage;

[0026] The other input of the second comparator is connected to one end of the sampling circuit used to connect the second transistor;

[0027] The output of the second comparator is used to connect to the voltage protection logic module.

[0028] The second comparator is used to output a third signal when the primary side voltage of the flyback power supply after the sampling circuit is greater than the preset operating voltage; and to output a fourth signal when the primary side voltage of the flyback power supply after the sampling circuit is less than the preset operating voltage.

[0029] The voltage protection logic module is used to activate the voltage protection logic when a third signal is received, and not to activate the voltage protection logic when a fourth signal is received.

[0030] Furthermore, the feedback resistor is a variable resistor.

[0031] Furthermore, the power module also includes: an RC snubber circuit and a fast recovery diode;

[0032] The RC snubber circuit is connected in series with the fast recovery diode and then in parallel across the primary side of the flyback power supply; the conduction direction of the fast recovery diode is towards the same terminal of the primary side of the flyback power supply.

[0033] Furthermore, the secondary side of the flyback power supply includes two sets, each set of which drives a corresponding switching transistor.

[0034] This utility model provides a driver board, including a power module that supports wide voltage input as described above.

[0035] The beneficial effects of this utility model are as follows: As a pioneering invention, this utility model provides a power supply module and driver board that support wide input voltage, including a flyback power supply for connecting a wide input voltage, wherein the primary side of the flyback power supply is connected in series with a feedback resistor, and the secondary side is used to drive a switching transistor; the power supply module also includes a control circuit; the control circuit includes a sampling circuit, a second transistor, a third transistor, a current source, a sampling resistor, a first comparator circuit, and a logic driver circuit; the input terminal of the sampling circuit is connected to one end of the feedback resistor, and the output terminal is connected to the emitter of the second transistor; the emitter of the third transistor is connected to the other end of the feedback resistor; the... The base of the second transistor is connected to the base of the third transistor; the collector of the second transistor is grounded through a current source; the collector of the second transistor is also connected to the base of the third transistor; the collector of the third transistor is grounded through a sampling resistor; the output of the logic drive circuit is connected to the control terminal of the first switching transistor in the flyback power supply; the logic drive circuit is connected to the sampling resistor to output a first PWM signal when the voltage across the sampling resistor is greater than a fixed voltage value; and outputs a second PWM signal when the voltage across the sampling resistor is less than a fixed voltage value; wherein the duty cycle of the first PWM signal is less than the duty cycle of the second PWM signal. Compared with existing technologies, on the one hand, the control circuit in this invention can output PWM signals with different duty cycles according to the voltage across the sampling resistor, thereby controlling the on or off duration of the first switching transistor in the flyback power supply, thus controlling the charging and discharging duration of the primary and secondary sides of the flyback power supply, and consequently changing the output voltage of the secondary side. This allows for support for a wide voltage input, meaning that regardless of the input voltage, the secondary side can output a driving voltage sufficient to drive the switching transistor, making it universally applicable. On the other hand, this invention only requires the flyback power supply stage power conversion circuit to provide the required driving voltage to the switching transistor. Therefore, the circuit structure is simple, the cost is low, and it achieves plug-and-play functionality. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a power supply module supporting wide voltage input provided by an embodiment of this utility model;

[0037] Figure 2 This is a schematic diagram of the structure of a control circuit provided in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the structure of a drive circuit for a switching transistor provided in an embodiment of this utility model;

[0039] Figure 4 This is a schematic diagram of the structure of a driver board provided in an embodiment of this utility model. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] The concept of this utility model is as follows: the control circuit adjusts the duty cycle of the PWM signal used to drive the switching transistor on the transformer according to the voltage of the feedback resistor, thereby adjusting the turns ratio of the driving transformer and changing the output of the driving transformer so that the output of the driving transformer meets the driving voltage required by the switching transistor.

[0042] Specifically: This utility model provides a power supply module and driver board supporting wide input voltage, including a flyback power supply for connecting a wide input voltage. The primary side of the flyback power supply is connected in series with a feedback resistor, and the secondary side is used to drive a switching transistor. The power supply module also includes a control circuit. The control circuit includes a sampling circuit, a second transistor, a third transistor, a current source, a sampling resistor, a first comparator circuit, and a logic driver circuit. The input terminal of the sampling circuit is connected to one end of the feedback resistor, and the output terminal is connected to the emitter of the second transistor. The emitter of the third transistor is connected to the other end of the feedback resistor. The base of the second transistor is connected to... The base of the third transistor is connected; the collector of the second transistor is grounded through a current source; the collector of the second transistor is also connected to the base of the second transistor; the collector of the third transistor is grounded through a sampling resistor; the output of the logic drive circuit is connected to the control terminal of the first switching transistor in the flyback power supply; the logic drive circuit is connected to the sampling resistor to output a first PWM signal when the voltage across the sampling resistor is greater than a fixed voltage value; and outputs a second PWM signal when the voltage across the sampling resistor is less than a fixed voltage value; wherein the duty cycle of the first PWM signal is less than the duty cycle of the second PWM signal.

[0043] An embodiment of a power supply module supporting wide voltage input:

[0044] Figure 1 This is a schematic diagram of the structure of a power supply module supporting wide voltage input provided by an embodiment of this utility model, as shown below. Figure 1 As shown, the power supply module includes: a flyback power supply for connecting a wide input voltage, a feedback resistor R1 connected in series with the primary side of the flyback power supply, and a control circuit; the secondary side of the flyback power supply is used to drive the switching transistor; the control terminal of the control circuit is connected to the control terminal of the first switching transistor T1 in the flyback power supply; the sampling terminal and the feedback terminal of the control circuit are connected across the feedback resistor R1.

[0045] The flyback power supply includes a drive transformer TR1 and a first switching transistor T1.

[0046] Since the driving transformer TR1 operates at a very high frequency, increasing the frequency can make the driving transformer TR1 smaller and reduce the size of the circuit.

[0047] The primary side of the drive transformer TR1 (i.e., the primary side of the flyback power supply) is used to connect to a wide input voltage. That is, the same-name terminal of the primary side of the drive transformer TR1 is used to connect to the positive terminal Uin+ of the wide input voltage, and the opposite-name terminal of the primary side of the drive transformer TR1 is used to connect to the negative terminal Uin- of the wide input voltage.

[0048] The secondary side of the drive transformer TR1 (i.e., the secondary side of the flyback power supply) is used to drive the switching transistor, which can be a high-power silicon IGBT or a silicon carbide MOSFET power device; this invention does not impose any particular limitation on either. Both silicon IGBTs and silicon carbide MOSFETs are voltage-driven devices. Silicon IGBTs generally require a relatively high drive voltage. When the driven switching transistor is an IGBT, the secondary side of the drive transformer TR1 needs to output +15V / -8V; when the driven switching transistor is a MOSFET, the secondary side of the drive transformer TR1 needs to output +18V / -4V. The scheme of adjusting the duty cycle of the first switching transistor T1 through the feedback resistor R1, thereby adjusting the output voltage of the secondary side, is very simple and flexible.

[0049] The secondary winding of the drive transformer TR1 can have one set, two sets, or multiple sets. This invention does not impose any particular limitation on this; the following explanation will use two sets of secondary windings of the drive transformer TR1 as an example. When the drive transformer TR1 has two or more sets of secondary windings, each set of secondary windings drives one switching transistor. Since the output voltage of the secondary windings of the drive transformer TR1 is the same, the type of switching transistor driven by each set of secondary windings is the same.

[0050] When the drive transformer TR1 has two sets of secondary windings, the electrical insulation distance between the two sets of secondary windings is greater than 6 mm, which is suitable for high-voltage applications. Having two sets of secondary windings on the drive transformer TR1 is equivalent to having two output channels: a first output channel and a second output channel. The first output channel includes the positive output terminal V... out1+ and negative output terminal V out1- The second output channel includes the positive output terminal V. out2+ and negative output terminal V out2- The positive output terminal V, pointing towards the first output channel, is connected in series with the opposite-named terminal of the first secondary side. out1+ The second secondary side has a positive output terminal V connected in series with the polarity of the secondary side, pointing towards the second output channel. out2+ The first set of secondary sides has a second capacitor C2 connected in parallel across its two ends, and the second set of secondary sides has a third capacitor C3 connected in parallel across its two ends.

[0051] The following example uses the first output channel, combined with... Figure 3 This paper describes the connection relationship between the power supply module supporting wide voltage input and the switching transistor provided in the embodiments of this utility model.

[0052] Figure 3 This is a schematic diagram of the structure of a drive circuit for a switching transistor provided in an embodiment of this utility model, as shown below. Figure 3 As shown, the driving circuit of the switching transistor includes a driving chip and a switching transistor.

[0053] The switching transistor can be either a MOSFET or an IGBT; this invention does not place particular limitation on either. This embodiment uses an IGBT as an example for illustrative purposes. It should be noted that silicon IGBTs and silicon carbide MOSFETs have different parasitic capacitances. Therefore, different drive resistors Rg and gate input capacitors Cg are selected for different power devices. This not only reduces the inductance of the drive circuit and prevents oscillations in the drive voltage, but also maintains a relatively fast system response speed.

[0054] Specifically, the driver chip includes a Pulse Width Modulation (PWM) signal terminal, a ground terminal Vs, a positive signal receiver V+, a negative signal receiver V-, and an output terminal Vout. The PWM terminal receives the PWM signal output from an external circuit, the ground terminal Vs is used for grounding, and the positive signal receiver V+ is connected to the positive output terminal Vout of the first output channel of the first secondary side of the flyback power supply. out1+ And the collector of the IGBT, the negative signal receiving terminal V- is used to connect to the negative output terminal V of the first output channel of the first secondary side of the flyback power supply. out1- The IGBT emitter and output terminal Vout are connected to the IGBT gate via a current-limiting resistor Rg.

[0055] With the drive voltage output from the flyback power supply and the PWM wave output from the external circuit, the IGBT can be driven to turn on or off.

[0056] To protect the driver chip, as an optional implementation, an optocoupler isolation device (not shown) is provided between the output of the flyback power supply and the driver chip of the switching transistor.

[0057] The first switching transistor T1 is an NPN MOSFET including a body diode D2. The on / off terminal of the first switching transistor T1 can be connected in series on the connection line between the same-name terminal of the primary side of the drive transformer TR1 and the positive terminal Uin+ of the wide input voltage, or it can be connected in series on the connection line between the opposite-name terminal of the primary side of the drive transformer TR1 and the negative terminal Uin- of the wide input voltage. This utility model does not make any special limitation in this regard. The following description takes the connection line between the on / off terminal of the first switching transistor T1 and the connection line between the same-name terminal of the primary side of the drive transformer TR1 and the positive terminal Uin+ of the wide input voltage as an example.

[0058] The wide input voltage can be a given value or a gradually changing value, etc. This utility model does not make any special limitation on it. This embodiment takes the wide input voltage range of [5 volts (V) to 100V] as an example for illustrative purposes.

[0059] The control circuit can be a control chip or a specific control circuit; this invention does not impose any particular limitation on either. When the control circuit is a control chip, the control terminal S of the control chip U1 is connected to the control terminal of the first switching transistor T1 in the flyback power supply; the sampling terminal AB and the feedback terminal FB of the control chip U1 are connected across the feedback resistor R1.

[0060] The following is combined Figure 2 The control circuit will be described in detail when it is a specific circuit.

[0061] Figure 2 This is a schematic diagram of a control circuit provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the control circuit includes a sampling circuit, a second transistor T2, a third transistor T3, a current source I1, a sampling resistor R, and a logic drive circuit.

[0062] Among them, the second transistor T2 and the third transistor T3 are both NPN type transistors.

[0063] Specifically, the sampling terminal AB of the control circuit is connected to the emitter of the second transistor T2 through a sampling loop; the feedback terminal FB of the control circuit is connected to the emitter of the third transistor T3; the base of the second transistor T2 is connected to the base of the third transistor T3; the collector of the second transistor T2 is grounded to GND through the current source I1; the collector of the second transistor T2 is also connected to the base of the second transistor T2; the collector of the third transistor T3 is grounded to GND through the sampling resistor R; the output terminal of the logic drive circuit is connected to the control terminal of the first switching transistor T1 in the flyback power supply; the logic drive circuit is connected to the sampling resistor R, which is used to output a first PWM signal when the voltage across the sampling resistor R is greater than a fixed voltage value, and to output a second PWM signal when the voltage across the sampling resistor R is less than a fixed voltage value.

[0064] The duty cycle of the first PWM signal is smaller than that of the second PWM signal.

[0065] It is understandable that when the first switch T1 is closed, the primary inductance of the drive transformer TR1 is charged, and when the first switch T1 is open, the primary inductance of the drive transformer TR1 is discharged. The longer the closing time of the first switch T1, the longer the charging time of the primary inductance of the drive transformer TR1, and the larger the voltage. Therefore, different duty cycles can make the conduction time of the first switch T1 different, which in turn can make the charging and discharging time of the inductance of the drive transformer TR1 different, thereby changing the magnitude of the voltage on the primary side of the drive transformer TR1, so that the secondary output of the drive transformer TR1 can meet the required voltage.

[0066] The sampling resistor R is used to connect to one end of the collector of the third transistor T3, where a signal point U is located. R Signal point U R The magnitude of the voltage can be used as the magnitude of the voltage across the sampling resistor R2.

[0067] In this circuit, the third transistor T3 and the second transistor T2 form a mirror constant current source circuit. The two ground terminals can share a common ground, serving as the negative terminal of the control circuit and connected to the negative terminal Uin- of the wide input voltage range.

[0068] The logic driving circuit includes a first comparator gm, logic circuitry, and a PWM wave generator Driver.

[0069] Specifically, the inverting input (i.e., "+") of the first comparator circuit gm is connected to the signal point U. R The non-inverting (i.e., "-") input of the first comparator circuit gm is used to connect to a fixed voltage value, and the output of the first comparator circuit gm is used to connect to the input of the logic circuit; the output of the logic circuit is connected to the control terminal of the first switching transistor T1 through the PWM wave generator Driver.

[0070] As an optional implementation, the inverting input of the first comparator circuit gm is connected to a fixed voltage value; the non-inverting input of the first comparator circuit gm is connected to the signal point U. R .

[0071] This invention does not impose any particular limitation on the signals connected to the inverting and non-inverting input terminals of the first comparator circuit gm. Subsequently, the signal point U is connected to the inverting input terminal of the first comparator circuit gm. R The example is illustrated by connecting a fixed voltage value to the non-inverting input of the first comparator circuit gm.

[0072] When the primary voltage of the flyback power supply through the sampling circuit is less than the forward voltage drop of the second transistor T2, the second transistor T2 is not turned on. Since the second transistor T2 and the third transistor T3 form a mirror constant current source circuit, when the second transistor T2 is not turned on, the third transistor T3 is also not turned on. Therefore, the signal point U...R The voltage is 0.

[0073] When the primary voltage of the flyback power supply through the sampling circuit is greater than the forward voltage drop of transistor T2, transistor T2 turns on. Since transistors T2 and T3 form a mirror constant current source circuit, when transistor T2 turns on, transistor T3 also turns on. The current flowing through transistor T2 is the same as the current flowing through transistor T3. Therefore, the signal point U... R The voltage is not 0.

[0074] The first comparator circuit gm is used at signal point U R When the voltage is greater than a fixed voltage value, the first signal is output; at signal point U R When the voltage is less than a fixed voltage value, a second signal is output.

[0075] The logic circuit is used to generate a first logic signal based on a first signal and a second logic signal based on a second signal.

[0076] The PWM wave generator driver is used to output a first PWM signal after receiving a first logic signal, and to output a second PWM signal after receiving a second logic signal.

[0077] To protect the control circuit, as an optional implementation, the control circuit is also used to activate the voltage protection logic of the controller circuit when the primary voltage of the drive transformer sampled by the feedback resistor R1 is greater than the preset operating voltage. Specifically, the control circuit also includes a second comparator a1 and a voltage protection logic module connected to the output terminal of the second comparator a1. The non-inverting input terminal (i.e., the "+" terminal) of the second comparator a1 is used to connect to the preset operating voltage; the inverting input terminal (i.e., the "-" terminal) of the second comparator a1 is connected to the end of the sampling circuit used to connect the second transistor T2.

[0078] As an optional implementation, the non-inverting input of the second comparator a1 is connected to one end of the sampling circuit used to connect the second transistor T2, and the inverting input of the second comparator a1 is used to connect to a preset operating voltage.

[0079] This invention does not impose any particular limitation on the signals connected to the inverting input terminal and the non-inverting input terminal of the second comparator a1. The following description will be based on the example of the non-inverting input terminal of the second comparator a1 being connected to a preset working voltage, and the inverting input terminal of the second comparator a1 being connected to the end of the sampling circuit used to connect to the second transistor T2.

[0080] The second comparator a1 is used to output a third signal when the primary side voltage of the flyback power supply after the sampling circuit is greater than the preset operating voltage; and to output a fourth signal when the primary side voltage of the flyback power supply after the sampling circuit is less than the preset operating voltage; the voltage protection logic module is used to activate the voltage protection logic when the third signal is received, and not activate the voltage protection logic when the fourth signal is received.

[0081] Among them, voltage protection logic can be used to cut off input voltages with a wide input voltage range.

[0082] To broaden the applicability of power modules that support wide voltage inputs, as an optional implementation, the feedback resistor R1 is a variable resistor.

[0083] The voltage relationship between the feedback resistor R1 and the primary side of the drive transformer TR1 can be found by referring to the following formula (1):

[0084]

[0085] Where N is the turns ratio of the drive transformer TR1; I1 is the current value of the current source I1 in the control circuit; V F V is the forward voltage drop of the first switching transistor T1; out1 The secondary voltage of the driving transformer TR1 is V, which is the positive output terminal of the first output channel. out1+ and the negative output terminal V of the first output channel out1- The difference, i.e., V out1 =V out1+ -V out1- .

[0086] The turns ratio N of the drive transformer TR1 is based on the primary voltage Vtr and secondary voltage V of the drive transformer TR1. out1 The primary voltage Vtr is determined, while the primary voltage Vtr depends on the equivalent series resistance ESR on the secondary circuit of the drive transformer TR1 and the current I in the secondary coil. out1 .

[0087] Specifically, the primary voltage Vtr of the drive transformer TR1 can be determined by the following formula (2):

[0088] Vtr=(V out1 +V D +I out1 *ESR)*N (2)

[0089] Since the sample-and-hold error amplifier samples the voltage when the secondary current is zero, that is, when the first switch T1 is closed, therefore I out1 *ESR is approximately zero, V DLet I be the forward voltage of the output diode (i.e., the third diode D3), taken as 0.3V. out1 *ESR = 0, V D Substituting 0.3 into formula (2), we can obtain the turns ratio N of the drive transformer TR1. The turns ratio N of the drive transformer TR1 can be obtained by referring to the following formula (3):

[0090]

[0091] It is understandable that when the forward voltage drop of the diode is 0.3V, it is smaller than Vtr and Vout1 and can be ignored. Therefore, the turns ratio N of the drive transformer TR1 can be transformed into the following formula (4):

[0092]

[0093] The essence of power device switching is the charging and discharging process of the power device's gate capacitance, thus requiring the drive power supply to provide a large instantaneous drive. To meet the needs of the power device drive power supply, a flyback power supply is used, and the switching frequency is generally tens to hundreds of kHz. The drive transformer TR1 has leakage inductance, which releases energy. If the leakage inductance spikes are not eliminated, they will have a reverse effect on the drive transformer TR1, affecting the output voltage of the secondary side of the drive transformer TR1 and potentially damaging the first switching transistor T1. To reduce the occurrence of this situation, as an optional implementation, an RC snubber circuit and a fast recovery diode D1 are also included.

[0094] Specifically, the RC snubber circuit is connected in series with the fast recovery diode D1 and then in parallel across the primary side of the flyback power supply; the conduction direction of the fast recovery diode is towards the same terminal of the primary side of the flyback power supply.

[0095] The RC absorption circuit includes a second resistor R2 and a first capacitor C1, with the first capacitor C1 connected in parallel across the two ends of the second resistor R2.

[0096] As an alternative implementation, the drive transformer TR1 uses a sandwich winding method, which can minimize leakage inductance and distributed capacitance.

[0097] This utility model provides a power supply module that supports wide voltage input, with a final size of 60mm × 30mm, which is relatively small.

[0098] This utility model provides a power supply module supporting a wide input voltage, including a flyback power supply for connecting a wide input voltage. The primary side of the flyback power supply is connected in series with a feedback resistor, and the secondary side is used to drive a switching transistor. The power supply module also includes a control circuit. The control circuit includes a sampling circuit, a second transistor, a third transistor, a current source, a sampling resistor, a first comparator circuit, and a logic drive circuit. The input terminal of the sampling circuit is connected to one end of the feedback resistor, and the output terminal is connected to the emitter of the second transistor. The emitter of the third transistor is connected to the other end of the feedback resistor. The base of the second transistor and the third transistor... The base of the first transistor is connected to the ground; the collector of the second transistor is grounded through a current source; the collector of the second transistor is also connected to the base of the second transistor; the collector of the third transistor is grounded through a sampling resistor; the output of the logic drive circuit is connected to the control terminal of the first switching transistor in the flyback power supply; the logic drive circuit is connected to a sampling resistor to output a first PWM signal when the voltage across the sampling resistor is greater than a fixed voltage value; and outputs a second PWM signal when the voltage across the sampling resistor is less than a fixed voltage value; wherein the duty cycle of the first PWM signal is less than the duty cycle of the second PWM signal. Compared with existing technologies, on the one hand, the control circuit in this invention can output PWM signals with different duty cycles according to the voltage across the sampling resistor, thereby controlling the on or off duration of the first switching transistor in the flyback power supply, thus controlling the charging and discharging duration of the primary and secondary sides of the flyback power supply, and consequently changing the output voltage of the secondary side. This allows for support for a wide voltage input, meaning that regardless of the input voltage, the secondary side can output a driving voltage sufficient to drive the switching transistor, making it universally applicable. On the other hand, this invention only requires the flyback power supply stage power conversion circuit to provide the required driving voltage to the switching transistor. Therefore, the circuit structure is simple, the cost is low, and it achieves plug-and-play functionality.

[0099] An embodiment of a driver board:

[0100] Figure 4 This is a schematic diagram of the structure of a driver board provided in an embodiment of this utility model, as shown below. Figure 4 As shown, the driver board includes a power module that supports wide voltage input.

[0101] The power supply module that supports wide voltage input can be referred to in the relevant description in the aforementioned "An Embodiment of a Power Supply Module Supporting Wide Voltage Input", which will not be repeated here.

[0102] As an optional implementation, the driver board can also integrate an optocoupler isolation module on each of the two secondary sides of the flyback power supply in a power module that supports wide voltage input, so that the output voltage of the secondary side of the flyback power supply can drive the switching transistor through the optocoupler isolation module.

[0103] The driver board provided in this embodiment of the present invention can achieve the same beneficial effects as the aforementioned power supply module that supports wide voltage input, which will not be described in detail here.

Claims

1. A power supply module supporting wide input voltage, comprising a flyback power supply for connecting a wide input voltage, characterized in that: The primary side of the flyback power supply is connected in series with the feedback resistor, and the secondary side is used to drive the switching transistor. The power module also includes a control circuit. The control circuit includes a sampling circuit, a second transistor, a third transistor, a current source, a sampling resistor, a first comparator circuit, and a logic drive circuit. The input terminal of the sampling circuit is connected to one end of the feedback resistor, and the output terminal is connected to the emitter of the second transistor; the emitter of the third transistor is connected to the other end of the feedback resistor. The base of the second transistor is connected to the base of the third transistor; the collector of the second transistor is grounded through a current source; the collector of the second transistor is also connected to the base of the second transistor. The collector of the third transistor is grounded through a sampling resistor; The output of the logic drive circuit is connected to the control terminal of the first switching transistor in the flyback power supply. The logic driver circuit uses a sampling resistor to output a first PWM signal when the voltage across the sampling resistor is greater than a fixed voltage value, and to output a second PWM signal when the voltage across the sampling resistor is less than the fixed voltage value. The duty cycle of the first PWM signal is smaller than that of the second PWM signal.

2. The power supply module supporting wide voltage input according to claim 1, characterized in that, The logic driving circuit includes a first comparator, a logic circuit, and a PWM wave generator connected to the control terminal of the first switching transistor. The sampling resistor is used to connect one end of the collector of the third transistor as a signal point to one input terminal of the first comparator circuit. The other input terminal of the first comparator circuit is used to connect a fixed voltage value. The output terminal of the first comparator circuit is used to connect to the input terminal of the logic circuit. The output of the logic circuit is connected to a PWM wave generator, which is used to control the PWM wave generator to output a first PWM signal or a second PWM signal. The first comparison circuit is used to output a first signal when the voltage at the signal point is greater than the fixed voltage value, and to output a second signal when the voltage is less than the fixed voltage value. The logic circuit is used to generate a first logic signal based on the first signal and to generate a second logic signal based on the second signal; The PWM wave generator is used to output a first PWM signal after receiving a first logic signal, and to output a second PWM signal after receiving a second logic signal.

3. The power supply module supporting wide voltage input according to claim 1, characterized in that, The control circuit also includes a second comparator; One input of the second comparator is used to connect to a preset operating voltage; The other input terminal of the second comparator is connected to one end of the sampling circuit used to connect the second transistor; The output of the second comparator is used to connect to the voltage protection logic module; The second comparator is used to output a third signal when the primary side voltage of the flyback power supply after passing through the sampling circuit is greater than the preset operating voltage; and to output a fourth signal when the primary side voltage of the flyback power supply after passing through the sampling circuit is less than the preset operating voltage. The voltage protection logic module is used to activate the voltage protection logic when the third signal is received, and not activate the voltage protection logic when the fourth signal is received.

4. The power supply module supporting wide voltage input according to claim 1, characterized in that, The feedback resistor is a variable resistor.

5. The power supply module supporting wide voltage input according to claim 1, characterized in that, The power module also includes: an RC snubber circuit and a fast recovery diode; The RC absorption circuit is connected in series with the fast recovery diode and then in parallel across the primary side of the flyback power supply; the conduction direction of the fast recovery diode points to the same terminal of the primary side of the flyback power supply.

6. The power supply module supporting wide voltage input according to any one of claims 1-5, characterized in that, The flyback power supply has two secondary sides, each of which drives a corresponding switching transistor.

7. A driver board, characterized in that, Includes a power supply module that supports wide voltage input as described in any one of claims 1-6.

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