Stable boost power supply device

Abstract

The utility model discloses a stable boost power supply device. The device comprises a transformer primary side circuit, a transformer secondary side circuit, a first diode circuit, a second diode circuit, a switch tube control circuit and a switch tube. A primary side circuit of the transformer is connected with power supply voltage; the switch tube control circuit provides a control signal for the switch tube so as to control the switch-on and switch-off of the switch tube; when the switching tube is switched on, the first diode circuit is controlled to be switched on, and voltage output by the transformer primary side circuit is transmitted to a load through the transformer secondary side circuit; when the switching tube is switched off, the second diode circuit is controlled to be switched on, and the voltage output by the transformer primary side circuit is transmitted to the load through the transformer secondary side circuit. According to the utility model, power supply voltage can be ensured to be accessed in the whole period of switch-on and switch-off of the switch tube, and power is supplied to an external load, so that higher power supply efficiency is realized; and the voltage transmitted to the load can be better stabilized, so that the output voltage is more stable.

Description

Technical Field

[0001] The utility model relates to the field of power supplies, in particular to a stable boosting power supply device. Background Art

[0002] The topology of the traditional BOOST circuit (i.e. boost circuit) is as follows Figures 1 to 3 As shown, its main components include a MOS tube, an inductor, and a diode (i.e. Figures 1 to 3 MOS tube Q1, inductor L1 and diode D1), capacitors (i.e. Figures 1 to 3 When the MOS tube Q1 is turned on, the current flows to Figure 2 As shown by the arrow a1 in the figure, the inductor L1 starts to charge and convert into magnetic energy. At this time, the diode D1 is reversely cut off, and the power supply Vin cannot supply power to the output load. The energy of the output load is only provided by the electric energy stored in the capacitor C2 (as shown in FIG. Figure 2 When the MOS tube Q1 is turned off, the current flows as shown in the following figure. Figure 3 As shown by the arrow b1 in the figure, the inductor L1 releases energy. At this time, the inductor L1 is like a battery connected in series with the power supply Vin to supply power to the output load and charge the capacitor C2 at the same time (as shown in FIG. Figure 3 As shown by arrow b2 in the figure, capacitor C2 also supplies power to the load during the charging process (as shown in the figure). Figure 3 as indicated by arrow b3 in FIG.

[0003] Therefore, in the traditional boost circuit, the power supply can only supply power to the load during the conduction period of the MOS tube, but cannot supply power to the load at all times. Figures 1 to 3 Therefore, this type of boost circuit has the problems of low power efficiency and unstable output voltage.

[0004] Therefore, a new boost power supply solution is urgently needed to achieve higher power efficiency and ensure output voltage stability. Utility Model Content

[0005] In view of this, the utility model provides a stable boost power supply device to solve the problems of low power efficiency and unstable output voltage in the existing boost circuit technology.

[0006] The utility model provides a stable boost power supply device, which includes a transformer primary circuit, a transformer secondary circuit, a first diode circuit, a second diode circuit, a switch tube control circuit and a switch tube:

[0007] The input end of the primary circuit of the transformer is electrically connected to an external power supply, and the output end of the secondary circuit of the transformer is electrically connected to an external load; the input end of the first diode circuit is coupled to the output end of the primary circuit of the transformer, and the output end of the first diode circuit is electrically connected to the external load through the secondary circuit of the transformer; the input end of the second diode circuit is electrically connected to the negative electrode of the output end of the primary circuit of the transformer, and the output end of the second diode circuit is electrically connected to the external load through the secondary circuit of the transformer; the output end of the switch control circuit is electrically connected to the input end of the switch, and the output end of the switch is electrically connected to both the negative electrode of the output end of the primary circuit of the transformer and the input end of the second diode circuit.

[0008] Optionally, the primary circuit of the transformer includes a primary winding, a first polarized capacitor C1, and a first capacitor C2;

[0009] Both the like-named end and the unlike-named end of the primary winding are coupled to the input end of the first diode circuit;

[0010] The like-named end of the primary winding is electrically connected to the external power supply, the positive electrode of the first polarized capacitor C1 and the first end of the first capacitor C2 are both connected to a common connection end between the like-named end of the primary winding and the external power supply, and the negative electrode of the first polarized capacitor C1 and the second end of the first capacitor C2 are both grounded;

[0011] The unlike-named end of the primary winding is electrically connected to both the output end of the switch and the input end of the second diode circuit.

[0012] Optionally, the first diode circuit includes a secondary winding and a first diode D1;

[0013] The like-named end of the secondary winding is coupled to the like-named end of the primary winding, the unlike-named end of the secondary winding is coupled to the unlike-named end of the primary winding, and the unlike-named end of the secondary winding is also grounded;

[0014] The like-named end of the secondary winding is also electrically connected to the input end of the secondary circuit of the transformer through the first diode D1.

[0015] Optionally, the secondary circuit of the transformer includes a second polarized capacitor C6 and a second capacitor C3;

[0016] The positive electrode of the second polarized capacitor C6 and the first end of the second capacitor C3 are both electrically connected to the load, and the negative electrode of the second polarized capacitor C6 and the second end of the second capacitor C3 are both grounded; the negative electrode of the first diode D1 and the output end of the second diode circuit are both connected to a common connection end between the positive electrode of the second polarized capacitor C6 and the load.

[0017] Optionally, the second diode circuit includes a second diode D2;

[0018] The positive electrode of the second diode D2 is electrically connected to the non-homonymous end of the primary winding, and the negative electrode of the second diode D2 is connected to the common connection end between the positive electrode of the second polarized capacitor C6 and the load.

[0019] Optionally, the switching transistor is specifically a MOS transistor Q1;

[0020] The switching transistor control circuit includes a single-chip microcomputer, a driver chip U1, and a first resistor R2;

[0021] The signal input pin IN of the driver chip U1 is electrically connected to the PWM signal output pin of the single-chip microcomputer, the positive power supply pin VCC of the driver chip U1 is electrically connected to the circuit power supply terminal, and the negative power supply pin VEE of the driver chip U1 is grounded; the source output pin Source and the drain output pin Sink of the driver chip U1 are connected together and are electrically connected to the gate of the MOS transistor Q1 through the first resistor R2;

[0022] The source of the MOS transistor Q1 is grounded, and the drain of the MOS transistor Q1 is electrically connected to both the negative electrode of the output terminal of the primary circuit of the transformer and the input terminal of the second diode circuit.

[0023] Optionally, the device further includes:

[0024] A voltage sampling circuit, the input terminal of the voltage sampling circuit is electrically connected to the output terminal of the secondary circuit of the transformer, and the output terminal of the voltage sampling circuit is electrically connected to the first signal input terminal of the switching transistor control circuit.

[0025] Optionally, the voltage sampling circuit includes a third capacitor C4, a second resistor R1, a third resistor R3, and a fourth resistor R6;

[0026] The first end of the second resistor R1 is electrically connected to the output terminal of the secondary circuit of the transformer, and the second end of the second resistor R1 is grounded through the fourth resistor R6; the first end of the third resistor R3 is connected to the common connection end between the second end of the second resistor R1 and the fourth resistor R6, and the second end of the third resistor R3 is electrically connected to the first signal input terminal of the switching transistor control circuit; the first end of the third capacitor C4 is connected to the common connection end between the second end of the third resistor R3 and the first signal input terminal of the switching transistor control circuit, and the second end of the third capacitor C4 is grounded.

[0027] Optionally, the device further includes:

[0028] A current sampling circuit, the input end of the current sampling circuit is electrically connected to the output end of the switching tube, and the output end of the current sampling circuit is electrically connected to the second signal input end of the switching tube control circuit.

[0029] Optionally, the current sampling circuit includes a fourth capacitor C5, a fifth resistor R4, and a sixth resistor R5;

[0030] The first end of the sixth resistor R5 is electrically connected to the output end of the switching tube, and the second end of the sixth resistor R5 is grounded; the first end of the fifth resistor R4 is connected to the common connection end between the first end of the sixth resistor R5 and the output end of the switching tube, and the second end of the fifth resistor R4 is electrically connected to the second signal input end of the switching tube control circuit; the first end of the fourth capacitor C5 is connected to the common connection end between the second end of the fifth resistor R4 and the second signal input end of the switching tube control circuit, and the second end of the fourth capacitor C5 is grounded.

[0031] The beneficial effects of the present utility model are as follows: The output end of the switching tube control circuit is electrically connected to the input end of the switching tube, and a control signal can be output to the switching tube through the switching tube control circuit to control the conduction and cutoff of the switching tube; Since the output end of the switching tube is electrically connected to the output end of the primary circuit of the transformer, and the output end of the primary circuit of the transformer is also electrically connected to the input end of the second diode circuit, and at the same time the output end of the primary circuit of the transformer is also coupled to the input end of the first diode circuit, when the switching tube receives the control signal output by the switching tube control circuit, it can realize its own conduction and cutoff, and control the conduction of the first diode circuit and the second diode circuit respectively during its own conduction and cutoff; Since the output ends of the first diode circuit and the second diode circuit are both electrically connected to the load through the secondary circuit of the transformer, during the conduction and cutoff of the switching tube, the secondary circuit of the transformer can output the power supply voltage connected to the primary circuit of the transformer to the load, realizing power supply to the load by the power supply during both the conduction and cutoff periods of the switching tube; The stable boost power supply device of the present utility model can ensure that the power supply voltage is connected during the entire period of conduction and cutoff of the switching tube and supply power to the external load, achieving higher power efficiency; At the same time, since the power supply voltage is connected during the entire period of conduction and cutoff of the switching tube, it can better stabilize the voltage transmitted to the load, making the output voltage more stable. Description of the Drawings

[0032] The features and advantages of the present utility model will be more clearly understood by referring to the accompanying drawings. The drawings are schematic and should not be construed as any limitation to the present utility model. In the drawings:

[0033] Figure 1 A circuit design diagram of a traditional boost power supply device is shown;

[0034] Figure 2 Shows the current flow diagram of a traditional boost power supply device when the switching transistor is conducting;

[0035] Figure 3 Shows the current flow diagram of a traditional boost power supply device when the switching transistor is turned off;

[0036] Figure 4 Shows the structural diagram of a stable boost power supply device in an embodiment of the present invention;

[0037] Figure 5 Shows the complete circuit design diagram of the stable boost power supply device in an embodiment of the present invention;

[0038] Figure 6 Shows the current flow diagram of the stable boost power supply device in an embodiment of the present invention when the switching transistor is conducting;

[0039] Figure 7 Shows the current flow diagram of the stable boost power supply device in an embodiment of the present invention when the switching transistor is turned off. Detailed implementation manners

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0041] Embodiment

[0042] This embodiment provides a stable boost power supply device, as Figure 4 shown, the device includes a primary circuit of a transformer, a secondary circuit of the transformer, a first diode circuit, a second diode circuit, a switching transistor control circuit, and a switching transistor:

[0043] The input end of the primary circuit of the transformer is electrically connected to an external power supply, and the output end of the secondary circuit of the transformer is electrically connected to an external load; the input end of the first diode circuit is coupled to the output end of the primary circuit of the transformer, and the output end of the first diode circuit is electrically connected to the external load through the secondary circuit of the transformer; the input end of the second diode circuit is electrically connected to the negative electrode of the output end of the primary circuit of the transformer, and the output end of the second diode circuit is electrically connected to the external load through the secondary circuit of the transformer; the output end of the switch control circuit is electrically connected to the input end of the switch, and the output end of the switch is electrically connected to both the negative electrode of the output end of the primary circuit of the transformer and the input end of the second diode circuit.

[0044] In this embodiment, the output end of the switch control circuit is electrically connected to the input end of the switch, and a control signal can be output to the switch through the switch control circuit to control the on and off of the switch; since the output end of the switch is electrically connected to the output end of the primary circuit of the transformer, and the output end of the primary circuit of the transformer is also electrically connected to the input end of the second diode circuit, and at the same time the output end of the primary circuit of the transformer is also coupled to the input end of the first diode circuit, when the switch receives the control signal output by the switch control circuit, it can realize its own on and off, and respectively control the first diode circuit and the second diode circuit to conduct during its own conduction and off periods; since the output ends of both the first diode circuit and the second diode circuit are electrically connected to the load through the secondary circuit of the transformer, during the on and off periods of the switch, the power supply voltage connected to the primary circuit of the transformer can be output to the load by the secondary circuit of the transformer, realizing power supply to the load by the power supply during both the on and off periods of the switch.

[0045] The stable boost power supply device of this embodiment can ensure that the power supply voltage is connected during the entire on and off periods of the switch and supply power to an external load, achieving higher power efficiency; at the same time, since the power supply voltage is connected during the entire on and off periods of the switch, the voltage transmitted to the load can be better stabilized, making the output voltage more stable.

[0046] It should be understood that the present invention only improves the hardware circuit structure of the boost power supply device and realizes a boost power supply device with higher power efficiency and more stable output based on the connection relationship between various electronic components in the hardware circuit structure, without involving the improvement of computer programs. The computer programs involved therein (such as the switch control circuit controlling the on and off of the switch, and the switch realizing the conduction of the first diode circuit and the second diode circuit respectively during the on and off periods) are all conventional signal control technologies in the circuit field.

[0047] Preferably, as Figures 5 to 7As shown, the primary circuit of the transformer includes a primary winding, a first polarized capacitor C1, and a first capacitor C2;

[0048] Both the same-name end and the different-name end of the primary winding are coupled to the input end of the first diode circuit;

[0049] The same-name end of the primary winding is electrically connected to an external power supply. The positive electrode of the first polarized capacitor C1 and the first end of the first capacitor C2 are both connected to a common connection end between the same-name end of the primary winding and the external power supply. The negative electrode of the first polarized capacitor C1 and the second end of the first capacitor C2 are both grounded;

[0050] The different-name end of the primary winding is electrically connected to the output end of the switching tube and the input end of the second diode circuit.

[0051] In the primary circuit of the transformer with the above structure, when the first diode circuit is conducting, the primary winding outputs voltage to the load through the first diode circuit. When the second diode circuit is conducting, the primary winding outputs voltage to the load through the second diode circuit.

[0052] Through the above primary circuit of the transformer, on the one hand, it can conveniently utilize the on and off of the switching tube to supply power to the load through different output paths; on the other hand, it is also convenient to use the turns ratio of the primary and secondary sides of the transformer to control the voltage magnitude output to the load, and thus it is convenient to realize a stable boost power supply. Among them, the first polarized capacitor and the first capacitor are connected in parallel between the primary winding of the transformer and the power supply, which can achieve multiple functions such as low-frequency and high-frequency filtering, energy storage, protection, and improvement of electromagnetic compatibility, helping to optimize the circuit performance, improve the system stability and reliability.

[0053] In Figures 5 to 7 , the 1st pin of the primary winding is the same-name end, and the 2nd pin is the different-name end. The 2nd pin is electrically connected to the output end of the switching tube on the one hand and the input end of the second diode circuit on the other hand.

[0054] Preferably, as Figures 5 to 7 shown, the first diode circuit includes a secondary winding and a first diode D1;

[0055] The same-name end of the secondary winding is coupled to the same-name end of the primary winding. The different-name end of the secondary winding is coupled to the different-name end of the primary winding. The different-name end of the secondary winding is also grounded;

[0056] The same-name end of the secondary winding is also electrically connected to the input end of the secondary circuit of the transformer through the first diode D1.

[0057] In the first diode circuit of the above structure, when the switching transistor is turned on, the voltage of the same-named end of the primary winding (i.e., pin 1) is positive. Utilizing the coupling between the primary winding and the secondary winding, the induced voltage of the same-named end of the secondary winding is also positive. Then, the first diode D1 conducts forward, and the voltage transmitted by the primary winding is output via the secondary circuit of the transformer, realizing the output of energy from the power supply to the load during the conduction of the switching transistor.

[0058] Specifically, in Figures 5 to 7 , the primary winding and the secondary winding together form the transformer T1. Pin 3 of the secondary winding is the same-named end, and pin 4 is the non-same-named end. When the switching transistor is turned on, the current flow in the transformer T1 is as shown by the arrows c1 and c2 in Figure 6 . Assuming the turns ratio between the primary winding and the secondary winding is 1:n (i.e., the turns ratio of the primary and secondary sides of the transformer T1 in Figures 5 to 7 ) and the forward voltage drop of the first diode D1 is VF1, then during the conduction of the switching transistor, the load voltage VOUTon provided to the load through the first diode circuit is VOUTon = n * VIN - VF1.

[0059] Preferably, as shown in Figures 5 to 7 , the secondary circuit of the transformer includes a second polarized capacitor C6 and a second capacitor C3;

[0060] The positive electrode of the second polarized capacitor C6 and the first end of the second capacitor C3 are both electrically connected to the load, and the negative electrode of the second polarized capacitor C6 and the second end of the second capacitor C3 are both grounded; the negative electrode of the first diode D1 and the output end of the second diode circuit are both connected to the common connection end between the positive electrode of the second polarized capacitor C6 and the load.

[0061] During their respective conduction periods, the first diode circuit and the second diode circuit both supply power to the load through the secondary circuit of the transformer with the above structure, which can achieve filtering and decoupling effects, provide a more stable and clean voltage for the load; it can also reduce electromagnetic interference and noise coupling, improve the stability of the entire power supply system, and ensure the normal operation of the load circuit.

[0062] Preferably, as shown in Figures 5 to 7 , the second diode circuit includes a second diode D2;

[0063] The positive electrode of the second diode D2 is electrically connected to the non-same-named end of the primary winding, and the negative electrode of the second diode D2 is connected to the common connection end between the positive electrode of the second polarized capacitor C6 and the load.

[0064] The above-mentioned second diode D2 is directly connected between the non-homonymous end of the primary winding and the secondary circuit of the transformer. Since the non-homonymous end of the primary winding is also electrically connected to the output end of the switching tube, the energy originally stored in the primary winding when it is turned on can be released when the switching tube is turned off, making the voltage at the non-homonymous end of the primary winding positive and the voltage at the homonymous end negative. As a result, the second diode D2 conducts forward, and the voltage transmitted by the primary winding is output via the secondary circuit of the transformer, realizing that energy is also output from the power supply to the load during the off period of the switching tube.

[0065] Specifically, when the switching tube is turned on, the current flow in the transformer T1 is as shown by the arrow d in Figure 7 . Assuming the voltage difference between the non-homonymous end and the homonymous end of the primary winding is V21 and the forward voltage drop of the second diode D2 is VF2, then during the off period of the switching tube, the load voltage VOUToff provided to the load through the second diode circuit is VIN + V21 - VF2.

[0066] Furthermore, since the turns ratio of the primary and secondary sides of the transformer T1, the voltage difference between the non-homonymous end and the homonymous end of the primary winding can be preset by selecting the transformer, and the voltage drops of the first diode D1 and the second diode D2 can also be preset by selecting the diodes, the appropriate transformer T1, the first diode D1, and the second diode D2 can be selected to make n*VIN - VF1 = VIN + V21 - VF2, and further make VOUTon = VOUToff. It can further make the load voltage obtained at the load end the same during the on and off periods of the switching tube, making the output of the entire boost power supply device more stable without fluctuations, contributing to the stability of the entire power supply system and ensuring the stable operation of the load circuit.

[0067] Preferably, as shown in Figures 5 to 7 , the switching tube is specifically a MOS tube Q1;

[0068] The switching tube control circuit includes a single-chip microcomputer, a driver chip U1, and a first resistor R2;

[0069] The signal input pin IN of the driver chip U1 is electrically connected to the PWM signal output pin of the single-chip microcomputer. The positive power supply pin VCC of the driver chip U1 is electrically connected to the circuit power supply terminal, and the negative power supply pin VEE of the driver chip U1 is grounded; the source output pin Source and the drain output pin Sink of the driver chip U1 are connected together and are electrically connected to the gate of the MOS tube Q1 through the first resistor R2;

[0070] The source of the MOS tube Q1 is grounded, and the drain of the MOS tube Q1 is electrically connected to both the negative pole of the output end of the primary circuit of the transformer and the input end of the second diode circuit.

[0071] In the switching transistor control circuit with the above structure, the signal input pin IN of the driving chip U1 is electrically connected to the PWM signal output pin of the single-chip microcomputer, and can receive the PWM modulation signal output by the PWM signal output pin of the single-chip microcomputer, and then drive the MOS transistor Q1 according to the PWM modulation signal to control the duty cycle of the MOS transistor Q1, thereby realizing the on and off control of the MOS transistor Q1.

[0072] Through the switching transistor control circuit with the above structure, the on and off of the MOS transistor Q1 can be controlled more precisely by the PWM signal output by the single-chip microcomputer; connecting the driving chip U1 between the MOS transistor Q1 and the single-chip microcomputer can improve the driving ability of the PWM.

[0073] Preferably, as Figure 4 shown, the device further includes:

[0074] a voltage sampling circuit, the input end of the voltage sampling circuit is electrically connected to the output end of the secondary side circuit of the transformer, and the output end of the voltage sampling circuit is electrically connected to the first signal input end of the switching transistor control circuit.

[0075] The input end of the voltage sampling circuit is electrically connected to the output end of the secondary side circuit of the transformer, and the output end of the secondary side circuit of the transformer is electrically connected to the load and outputs voltage to the load. Therefore, the load voltage at the load end can be grasped in real time through the voltage sampling circuit, and the input end of the voltage sampling circuit is electrically connected to the first signal input end of the switching transistor control circuit, which can realize the feedback of the load voltage to the switching transistor control circuit, perform feedback regulation on the switching transistor, and further enable the load voltage to be stabilized at the target voltage, ensuring the stability of the entire boost power supply device. Among them, when the load voltage is fed back to the switching transistor control circuit, the switching transistor control circuit adjusts the PWM signal, and then adjusts the duty cycle of the MOS transistor Q1, so that the voltage output by the secondary side circuit of the transformer is stabilized at the target voltage.

[0076] Preferably, as Figures 5 to 7 shown, the voltage sampling circuit includes a third capacitor C4, a second resistor R1, a third resistor R3, and a fourth resistor R6;

[0077] The first end of the second resistor R1 is electrically connected to the output end of the secondary side circuit of the transformer, and the second end of the second resistor R1 is grounded through the fourth resistor R6; the first end of the third resistor R3 is connected to the common connection end between the second end of the second resistor R1 and the fourth resistor R6, and the second end of the third resistor R3 is electrically connected to the first signal input end of the switching tube control circuit; the first end of the third capacitor C4 is connected to the common connection end between the second end of the third resistor R3 and the first signal input end of the switching tube control circuit, and the second end of the third capacitor C4 is grounded.

[0078] In the voltage sampling circuit with the above structure, the second resistor R1 and the fourth resistor R6 form a resistor voltage division circuit. The common connection end between the second resistor R1 and the fourth resistor R6 is used as a reference point, and then it is connected to the first signal input end of the switching tube control circuit (i.e., Figures 5 to 7 the A / D1 port of the single-chip microcomputer in) through the third resistor R3 to realize voltage sampling and feedback.

[0079] Preferably, as Figure 4 shown, the device further includes:

[0080] a current sampling circuit, the input end of the current sampling circuit is electrically connected to the output end of the switching tube, and the output end of the current sampling circuit is electrically connected to the second signal input end of the switching tube control circuit.

[0081] The input end of the current sampling circuit is electrically connected to the output end of the switching tube, and the switching current of the switching tube can be collected. On the one hand, this switching current can reflect the current situation in the switching tube, facilitating real-time monitoring of whether the current passing through the switching tube reaches the maximum allowable current; the output end of the current sampling circuit is electrically connected to the input end of the switching tube control circuit, so it is possible to control the on and off of the switching tube according to the collected switching current, achieving protection for the switching tube in the entire device; on the other hand, this switching tube current can also reflect the current change rate (i.e., di / dt), and the current change rate can reflect the working conditions of the load end (including normal, no-load, overload, short-circuit, etc.). Therefore, the switching current is also convenient for grasping the working conditions of the load end and protecting the load.

[0082] Preferably, as Figures 5 to 7 shown, the current sampling circuit includes a fourth capacitor C5, a fifth resistor R4, and a sixth resistor R5;

[0083] The first end of the sixth resistor R5 is electrically connected to the output end of the switching transistor, and the second end of the sixth resistor R5 is grounded; the first end of the fifth resistor R4 is connected to the common connection end between the first end of the sixth resistor R5 and the output end of the switching transistor, and the second end of the fifth resistor R4 is electrically connected to the second signal input end of the switching transistor control circuit; the first end of the fourth capacitor C5 is connected to the common connection end between the second end of the fifth resistor R4 and the second signal input end of the switching transistor control circuit, and the second end of the fourth capacitor C5 is grounded.

[0084] In the current sampling circuit with the above structure, a sixth resistor R5 is connected to the output end of the switching transistor (i.e., the source electrode of the MOS transistor Q1 is connected through the sixth resistor R5). This sixth resistor R5 is a current sampling resistor, and the current in the sixth resistor R5 is transmitted through the fifth resistor R4 to the second signal input end of the switching transistor control circuit (specifically, Figures 5 to 7 the A / D2 port of the single-chip microcomputer in

[0085] to achieve current sampling and feedback. It should be understood that it is a conventional function of the single-chip microcomputer to adjust the PWM modulation signal according to the feedback voltage or current. Specific details are not elaborated here. The single-chip microcomputer can select a suitable specification or product model according to the actual situation.

[0086] In this embodiment, the driving chip U1 selects a gate driving chip of the ZXGD3006E6TA model, and each resistor, capacitor, MOS transistor, transformer, and diode are all selected with suitable specifications or product models according to actual needs, which are not listed here.

[0087] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A stable boost power supply device, characterized in that, The device includes a primary circuit of a transformer, a secondary circuit of the transformer, a first diode circuit, a second diode circuit, a switch control circuit, and a switch: The input end of the primary circuit of the transformer is electrically connected to an external power supply, and the output end of the secondary circuit of the transformer is electrically connected to an external load; the input end of the first diode circuit is coupled to the output end of the primary circuit of the transformer, and the output end of the first diode circuit is electrically connected to the external load through the secondary circuit of the transformer; the input end of the second diode circuit is electrically connected to the negative electrode of the output end of the primary circuit of the transformer, and the output end of the second diode circuit is electrically connected to the external load through the secondary circuit of the transformer; the output end of the switch control circuit is electrically connected to the input end of the switch, and the output end of the switch is electrically connected to both the negative electrode of the output end of the primary circuit of the transformer and the input end of the second diode circuit.

2. The stable boost power supply device according to claim 1, wherein The primary circuit of the transformer includes a primary winding, a first polarized capacitor C1, and a first capacitor C2; Both the same-name end and the non-same-name end of the primary winding are coupled to the input end of the first diode circuit; The same-name end of the primary winding is electrically connected to the external power supply, the positive electrode of the first polarized capacitor C1 and the first end of the first capacitor C2 are both connected to a common connection end between the same-name end of the primary winding and the external power supply, and the negative electrode of the first polarized capacitor C1 and the second end of the first capacitor C2 are both grounded; The non-same-name end of the primary winding is electrically connected to both the output end of the switch and the input end of the second diode circuit.

3. The stable boost power supply device according to claim 2, characterized in that The first diode circuit includes a secondary winding and a first diode D1; The same-name end of the secondary winding is coupled to the same-name end of the primary winding, the non-same-name end of the secondary winding is coupled to the non-same-name end of the primary winding, and the non-same-name end of the secondary winding is also grounded; The same-name end of the secondary winding is also electrically connected to the input end of the secondary circuit of the transformer through the first diode D1.

4. The stable boost power supply device according to claim 3, wherein, The secondary circuit of the transformer includes a second polarized capacitor C6 and a second capacitor C3; The positive electrode of the second polarized capacitor C6 and the first end of the second capacitor C3 are both electrically connected to the load, and the negative electrode of the second polarized capacitor C6 and the second end of the second capacitor C3 are both grounded; the negative electrode of the first diode D1 and the output end of the second diode circuit are both connected to a common connection end between the positive electrode of the second polarized capacitor C6 and the load.

5. The stable boost power supply device according to claim 4, characterized in that, The second diode circuit includes a second diode D2; The positive electrode of the second diode D2 is electrically connected to the non-same-name end of the primary winding, and the negative electrode of the second diode D2 is connected to a common connection end between the positive electrode of the second polarized capacitor C6 and the load.

6. The stable boost power supply device according to claim 1, wherein The switch is specifically a MOS transistor Q1; The switch control circuit includes a single-chip microcomputer, a driving chip U1, and a first resistor R2; The signal input pin IN of the driving chip U1 is electrically connected to the PWM signal output pin of the single-chip microcomputer. The positive power supply pin VCC of the driving chip U1 is electrically connected to the circuit power supply terminal, and the negative power supply pin VEE of the driving chip U1 is grounded; the source output pin Source and the drain output pin Sink of the driving chip U1 are connected together and are electrically connected to the gate of the MOS transistor Q1 through the first resistor R2; The source of the MOS transistor Q1 is grounded, and the drain of the MOS transistor Q1 is electrically connected to both the negative electrode of the output terminal of the primary circuit of the transformer and the input terminal of the second diode circuit.

7. The stable boost power supply device according to claim 1, wherein The device further includes: A voltage sampling circuit, the input terminal of the voltage sampling circuit is electrically connected to the output terminal of the secondary circuit of the transformer, and the output terminal of the voltage sampling circuit is electrically connected to the first signal input terminal of the switching tube control circuit.

8. The stable boost power supply device according to claim 7, wherein The voltage sampling circuit includes a third capacitor C4, a second resistor R1, a third resistor R3, and a fourth resistor R6; The first end of the second resistor R1 is electrically connected to the output terminal of the secondary circuit of the transformer, and the second end of the second resistor R1 is grounded through the fourth resistor R6; the first end of the third resistor R3 is connected to the common connection end between the second end of the second resistor R1 and the fourth resistor R6, and the second end of the third resistor R3 is electrically connected to the first signal input terminal of the switching tube control circuit; the first end of the third capacitor C4 is connected to the common connection end between the second end of the third resistor R3 and the first signal input terminal of the switching tube control circuit, and the second end of the third capacitor C4 is grounded.

9. The stable boost power supply device according to claim 1, wherein The device further includes: A current sampling circuit, the input terminal of the current sampling circuit is electrically connected to the output terminal of the switching tube, and the output terminal of the current sampling circuit is electrically connected to the second signal input terminal of the switching tube control circuit.

10. The stable boost power supply device according to claim 9, wherein, The current sampling circuit includes a fourth capacitor C5, a fifth resistor R4, and a sixth resistor R5; The first end of the sixth resistor R5 is electrically connected to the output terminal of the switching tube, and the second end of the sixth resistor R5 is grounded; the first end of the fifth resistor R4 is connected to the common connection end between the first end of the sixth resistor R5 and the output terminal of the switching tube, and the second end of the fifth resistor R4 is electrically connected to the second signal input terminal of the switching tube control circuit; the first end of the fourth capacitor C5 is connected to the common connection end between the second end of the fifth resistor R4 and the second signal input terminal of the switching tube control circuit, and the second end of the fourth capacitor C5 is grounded.

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