Two-way output power supply

Abstract

The utility model discloses a double-path output power supply, which comprises a transformer, a primary side circuit, a first power supply output circuit, a second power supply output circuit, a switching tube control circuit and a switching tube, the transformer is connected with power supply voltage through a primary side circuit; 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 power supply output circuit is controlled to be switched on, and the power supply voltage accessed by the transformer is transmitted to the first load through the first power supply output circuit; and when the switching tube is switched off, the second power output circuit is controlled to be switched on, and the power voltage accessed by the transformer is transmitted to the second load through the second power output circuit. According to the utility model, dual-path power supply output is realized through a simple circuit structure, power is supplied to dual-path loads, the application range is widened, dual-path output can be realized without increasing the number of power supplies, and the circuit cost is relatively low; the power supply voltage can be fully utilized, and the circuit utilization efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of power supplies, in particular to a dual-channel output power supply. 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, there is only one output, which can only connect to a single load, and the application range is narrow. If multiple loads need to be connected, multiple boost circuits need to be set up, and the circuit cost is high; and this output can only be powered by the power supply to the load during the conduction period of the MOS tube, and the circuit utilization efficiency is low.

[0004] Therefore, a new boost power supply solution is urgently needed to broaden the scope of application and improve circuit utilization efficiency. Utility Model Content

[0005] In view of this, the utility model provides a dual-output power supply to solve the problems of narrow application range and low circuit utilization efficiency in the existing boost circuit technology.

[0006] The utility model provides a dual-output power supply, the power supply comprising a transformer, a primary circuit, a first power output circuit, a second power output circuit, a switch tube control circuit and a switch tube;

[0007] The primary side circuit is disposed on the primary side of the transformer, and the transformer is electrically connected to an external power supply through the primary side circuit; the first power output circuit is disposed on the secondary side of the transformer, the input end of the first power output circuit is electrically connected to the secondary side of the transformer, and the output end of the first power output circuit is electrically connected to an external first load; the second power output circuit is disposed on the primary side of the transformer, the input end of the second power output circuit is electrically connected to the primary side of the transformer, and the output end of the second power output circuit is electrically connected to an external second load; the output end of the switching tube control circuit is electrically connected to the input end of the switching tube, and the output end of the switching tube is electrically connected to both the primary side of the transformer and the input end of the second power output circuit.

[0008] Optionally, the transformer includes a primary winding and a secondary winding;

[0009] The primary side circuit includes a first polarized capacitor C1 and a first capacitor C2;

[0010] 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, and the negative electrode of the first polarized capacitor C1 and the second end of the first capacitor C2 are both grounded;

[0011] The non-same-name end of the primary winding is electrically connected to both the output end of the switching tube and the input end of the second power output circuit.

[0012] Optionally, the first power output circuit includes a first diode D1, a second polarized capacitor C6, and a second capacitor C3;

[0013] 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;

[0014] The same-name end of the secondary winding is also electrically connected to the first load through the first diode D1; the positive electrode of the second polarized capacitor C6 and the first end of the second capacitor C3 are both connected to a common connection end between the first diode D1 and the first load, and the negative electrode of the second polarized capacitor C6 and the second end of the second capacitor C3 are both grounded.

[0015] Optionally, the second power output circuit includes a second diode D2, a third polarized capacitor C8, and a third capacitor C7;

[0016] 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 electrically connected to the second load; the positive electrode of the third polarized capacitor C8 and the first end of the third capacitor C7 are both connected to the common connection end between the negative electrode of the second diode D2 and the second load, and the negative electrode of the third polarized capacitor C8 and the second end of the third capacitor C7 are both grounded.

[0017] Optionally, the switching tube is specifically a MOS tube Q1;

[0018] The switching tube control circuit includes a single-chip microcomputer, a driving chip U1, and a first resistor R2;

[0019] 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 tube Q1 through the first resistor R2;

[0020] The source of the MOS tube Q1 is grounded, and the drain of the MOS tube Q1 is electrically connected to both the non-homonymous end of the primary winding and the input end of the second power output circuit.

[0021] Optionally, the power supply further includes:

[0022] A current sampling circuit, the input end of the current sampling circuit is electrically connected to the source of the MOS tube Q1, and the output end of the current sampling circuit is electrically connected to the first signal input end of the switching tube control circuit.

[0023] Optionally, the current sampling circuit includes a fifth capacitor C5, an eighth resistor R4, and a ninth resistor R5;

[0024] The first end of the ninth resistor R5 is electrically connected to the source of the MOS tube Q1, and the second end of the ninth resistor R5 is grounded; the first end of the eighth resistor R4 is connected to the common connection end between the first end of the ninth resistor R5 and the source of the MOS tube Q1, and the second end of the eighth resistor R4 is electrically connected to the first signal input end of the switching tube control circuit; the first end of the fifth capacitor C5 is connected to the common connection end between the second end of the eighth resistor R4 and the first signal input end of the switching tube control circuit, and the second end of the fifth capacitor C5 is grounded.

[0025] Optionally, the power supply further includes:

[0026] The first voltage sampling circuit, the input end of the first voltage sampling circuit is electrically connected to the output end of the first power supply output circuit, and the output end of the first voltage sampling circuit is electrically connected to the second signal input end of the switching tube control circuit;

[0027] The second voltage sampling circuit, the input end of the second voltage sampling circuit is electrically connected to the output end of the second power supply output circuit, and the output end of the second voltage sampling circuit is electrically connected to the third signal input end of the switching tube control circuit.

[0028] Optionally, the first voltage sampling circuit includes a third capacitor C4, a second resistor R1, a third resistor R3, and a fourth resistor R6;

[0029] The first end of the second resistor R1 is electrically connected to the output end of the first power supply output circuit, 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 second 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 second signal input end of the switching tube control circuit, and the second end of the third capacitor C4 is grounded;

[0030] And / or, the second voltage sampling circuit includes a fourth capacitor C9, a fifth resistor R7, a sixth resistor R8, and a seventh resistor R9;

[0031] The first end of the fifth resistor R7 is electrically connected to the output end of the second power supply output circuit, and the second end of the fifth resistor R7 is grounded through the seventh resistor R9; the first end of the sixth resistor R8 is connected to the common connection end between the second end of the fifth resistor R7 and the seventh resistor R9, and the second end of the sixth resistor R8 is electrically connected to the third signal input end of the switching tube control circuit; the first end of the fourth capacitor C9 is connected to the common connection end between the second end of the sixth resistor R8 and the third signal input end of the switching tube control circuit, and the second end of the fourth capacitor C9 is grounded.

[0032] Advantages of the present utility model: 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 primary side of the transformer, and on the one hand, the primary side of the transformer is electrically connected to the input end of the second power output circuit, and on the other hand, it is coupled to the secondary side of the transformer, and the secondary side of the transformer is electrically connected to the input end of the first power output circuit, therefore, when the switching tube receives the control signal output by the switching tube control circuit, it can realize its own conduction and cutoff, and during its own conduction and cutoff periods, respectively control the conduction of the first power output circuit and the second power output circuit; since the output end of the first power output circuit is electrically connected to the first load, and the output end of the second power output circuit is electrically connected to the second load, therefore, during the conduction and cutoff of the switching tube, the power supply to the first load and the second load is respectively realized, and thus the dual-channel power output is realized.

[0033] The dual-channel output power supply of the present utility model can ensure that the power supply voltage is connected throughout the entire period of the conduction and cutoff of the switching tube, and respectively supply power to the external first load and second load. It not only realizes the dual-channel power output through a simple circuit structure, supplies power to the dual-channel load, broadens the application range, and does not need to increase the number of power supplies to achieve the dual-channel output, with a lower circuit cost; but also can make full use of the power supply voltage and improve the circuit utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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 imposing any limitation on the present utility model. In the drawings:

[0035] Figure 1 Shows the circuit design diagram of a traditional boost power supply;

[0036] Figure 2 Shows the current flow diagram of the traditional boost power supply when the switching tube is conducting;

[0037] Figure 3 Shows the current flow diagram of the traditional boost power supply when the switching tube is cutoff;

[0038] Figure 4 Shows the structure diagram of a dual-channel output power supply in Embodiment 1 of the present utility model;

[0039] Figure 5 Shows the complete circuit design diagram of the dual-channel output power supply in Embodiment 1 of the present utility model;

[0040] Figure 6 Shows the current flow diagram of the dual-channel output power supply in Embodiment 1 of the present utility model when the switching tube is conducting;

[0041] Figure 7It shows the current flow diagram of the dual-output power supply in the first embodiment of the present invention when the switching tube is turned off. Detailed implementation manners

[0042] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] Embodiment

[0044] This embodiment provides a dual-output power supply, as Figure 4 shown, the power supply includes a primary circuit of a transformer, a secondary circuit of the transformer, a first diode circuit, a second diode circuit, a switching tube control circuit, and a switching tube:

[0045] 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 switching tube control circuit is electrically connected to the input end of the switching tube, and the output end of the switching tube 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.

[0046] In the power supply with the above structure, the transformer accesses the power supply voltage through the primary circuit; the switching tube control circuit provides a control signal to the switching tube to control the conduction and turn-off of the switching tube; when the switching tube is conducting, it controls the first power output circuit to conduct; when the switching tube is turned off, it controls the second power output circuit to conduct; when the first power output circuit is conducting, it outputs a voltage to the first load; when the second power output circuit is conducting, it outputs a voltage to the second load.

[0047] In this embodiment, the output terminal of the switch control circuit is electrically connected to the input terminal of the switch. A control signal can be output to the switch through the switch control circuit to control the conduction and cutoff of the switch. Since the output terminal of the switch is electrically connected to the primary side of the transformer, and the primary side of the transformer is electrically connected to the input terminal of the second power output circuit on the one hand and coupled to the secondary side of the transformer on the other hand, and the secondary side of the transformer is electrically connected to the input terminal of the first power output circuit, when the switch receives the control signal output by the switch control circuit, it can achieve its own conduction and cutoff, and during its own conduction and cutoff periods, control the first power output circuit and the second power output circuit to conduct respectively. Since the output terminal of the first power output circuit is electrically connected to the first load and the output terminal of the second power output circuit is electrically connected to the second load, during the conduction and cutoff of the switch, the power supply of the first load and the second load is realized respectively, and thus the dual - power output is achieved.

[0048] The dual - output power supply of this embodiment can ensure that the power supply voltage is connected during the entire period of the conduction and cutoff of the switch, and supply power to the external first load and second load respectively. It realizes the dual - power output through a simple circuit structure, supplies power to the dual - load, broadens the application range, and does not need to increase the number of power supplies to achieve dual - output, with a lower circuit cost. Moreover, it can make full use of the power supply voltage and improve the circuit utilization efficiency.

[0049] It should be understood that the present utility model realizes the dual - output power supply only by improving the hardware circuit structure of the power supply and based on the connection relationship between the electronic components in the hardware circuit structure, and does not involve the improvement of computer programs. The computer programs involved therein (such as the switch control circuit controlling the conduction and cutoff of the switch, and the switch realizing the conduction of the first power output circuit and the second power output circuit respectively during conduction and cutoff) are all conventional signal control technologies in the circuit field.

[0050] Preferably, as Figures 5 to 7 shown, the transformer includes a primary winding and a secondary winding;

[0051] The primary - side circuit includes a first polarized capacitor C1 and a first capacitor C2;

[0052] The same - name terminal 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 the common connection end between the same - name terminal 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;

[0053] The non - same - name terminal of the primary winding is electrically connected to both the output terminal of the switch and the input terminal of the second power output circuit.

[0054] In the transformer and the primary circuit with the above structure, when the first power output circuit is turned on, the primary winding outputs voltage to the first load through the first power output circuit; when the second power output circuit is turned on, the primary winding outputs voltage to the second load through the second power output circuit.

[0055] Through the above transformer and primary circuit, on the one hand, it is convenient to utilize the on and off of the switching tube to realize the conduction of different output paths, and then realize the power supply to the dual-load respectively; on the other hand, it is also convenient to utilize the turns ratio of the primary and secondary sides of the transformer to control the magnitude of the voltage output to the first load, and then facilitate the power supply control of the first load. Among them, a first polarized capacitor and a first capacitor are connected in parallel between the primary winding of the transformer and the power supply, which can realize 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.

[0056] In Figures 5 to 7 it, the transformer is T1 (specifically, the EE10-2+2P model transformer is selected in this embodiment). The 1st pin of the primary winding is the same-named terminal, and the 2nd pin is the non-same-named terminal. The 2nd pin is electrically connected to the output terminal of the switching tube on the one hand and the input terminal of the second power output circuit on the other hand; the 3rd pin of the secondary winding is the same-named terminal, and the 4th pin is the non-same-named terminal. The 3rd pin is electrically connected to the input terminal of the first power output circuit.

[0057] Preferably, as Figures 5 to 7 shown, the first power output circuit includes a first diode D1, a second polarized capacitor C6, and a second capacitor C3;

[0058] The same-named terminal of the secondary winding is coupled to the same-named terminal of the primary winding, the non-same-named terminal of the secondary winding is coupled to the non-same-named terminal of the primary winding, and the non-same-named terminal of the secondary winding is also grounded;

[0059] The same-named terminal of the secondary winding is also electrically connected to the first load through the first diode D1; the positive electrode of the second polarized capacitor C6 and the first end of the second capacitor C3 are both connected to the common connection end between the first diode D1 and the first load, and the negative electrode of the second polarized capacitor C6 and the second end of the second capacitor C3 are both grounded.

[0060] In the first power output circuit with the above structure, when the first diode D1 is forward-conducted, it outputs the voltage transmitted by the primary winding to the first load.

[0061] In the first power output circuit with the above structure, when the switching transistor is turned on, the voltage at 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 at the same-named end of the secondary winding (i.e., pin 3) is also positive. Then, the first diode D1 conducts forward, supplying power to the first load, realizing the output of energy from the power supply to the load during the conduction of the switching transistor. Among them, through the second polarized capacitor and the second capacitor, filtering and decoupling functions can be achieved, providing a more stable and clean voltage for the first load; it can also reduce electromagnetic interference and noise coupling, improving the stability of the entire power supply system and ensuring the normal operation of the first load.

[0062] Specifically, in Figures 5 to 7 , when the switching transistor is turned on, the current flow direction 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 first load voltage VOUT1 provided to the first load through the first power output circuit is VOUT1 = n*VIN - VF1. Obviously, this first load voltage can be higher than VIN or lower than VIN, depending on the specific value of n.

[0063] Preferably, as shown in Figures 5 to 7 , the second power output circuit includes a second diode D2, a third polarized capacitor C8, and a third capacitor C7;

[0064] 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 electrically connected to the second load; the positive electrode of the third polarized capacitor C8 and the first end of the third capacitor C7 are both connected to the common connection end between the negative electrode of the second diode D2 and the second load, and the negative electrode of the third polarized capacitor C8 and the second end of the third capacitor C7 are both grounded.

[0065] In the second power output circuit with the above structure, when the second diode D2 conducts forward, it outputs the voltage transmitted by the primary winding to the second load.

[0066] By connecting the above second power output circuit to the non-same-named end of the primary winding, since the non-same-named end of the primary winding is also electrically connected to the output end of the switching transistor, the energy originally stored in the primary winding when it was on can be released when the switching transistor is turned off, making the voltage at the non-same-named end of the primary winding positive and the voltage at the same-named end negative. As a result, the second diode D2 conducts forward, supplying power to the second load, realizing the output of energy from the power supply to the second load during the turn-off of the switching transistor.

[0067] Specifically, when the switching transistor is turned on, the current flow in the transformer T1 is as shown by the arrow d in Figure 7 . Let the voltage difference between the non-homonymous end and the homonymous end of the primary winding be V21, and the forward voltage drop of the second diode D2 be VF2. Then, during the off period of the switching transistor, the second load voltage VOUT2 provided to the second load through the second power supply output circuit is VIN + V21 - VF2.

[0068] Preferably, as shown in Figures 5 to 7 , the switching transistor is specifically a MOS transistor Q1;

[0069] The switching transistor control circuit includes a single-chip microcomputer, a driving chip U1, and a first resistor R2;

[0070] 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;

[0071] The source of the MOS transistor Q1 is grounded, and the drain of the MOS transistor Q1 is electrically connected to both the non-homonymous end of the primary winding and the input end of the second power supply output circuit.

[0072] 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. Then, according to the PWM modulation signal, it drives the MOS transistor Q1 to control the duty cycle of the MOS transistor Q1, thereby realizing the control of the on and off of the MOS transistor Q1.

[0073] Through the switching transistor control circuit with the above structure, the on and off of the MOS transistor Q1 can be more accurately controlled 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.

[0074] Preferably, as shown in Figure 4 , the power supply further includes:

[0075] A current sampling circuit, the input end of the current sampling circuit is electrically connected to the source of the MOS transistor Q1, and the output end of the current sampling circuit is electrically connected to the first signal input end of the switching transistor control circuit.

[0076] 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. Therefore, it is possible to control the conduction and cutoff of the switching tube according to the collected switching current, achieving protection for the switching tube in the entire power supply. 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 also facilitates understanding the working conditions of the load end, protecting both the first load and the second load.

[0077] Preferably, as Figures 5 to 7 shown, the current sampling circuit includes a fifth capacitor C5, an eighth resistor R4, and a ninth resistor R5;

[0078] The first end of the ninth resistor R5 is electrically connected to the source electrode of the MOS transistor Q1, and the second end of the ninth resistor R5 is grounded. The first end of the eighth resistor R4 is connected to the common connection end between the first end of the ninth resistor R5 and the source electrode of the MOS transistor Q1, and the second end of the eighth resistor R4 is electrically connected to the first signal input end of the switching tube control circuit. The first end of the fifth capacitor C5 is connected to the common connection end between the second end of the eighth resistor R4 and the first signal input end of the switching tube control circuit, and the second end of the fifth capacitor C5 is grounded.

[0079] In the current sampling circuit with the above structure, a ninth resistor R5 is connected to the source electrode of the MOS transistor Q1. This ninth resistor R5 is a current sampling resistor, and the current in the ninth resistor R5 is transmitted to the first signal input end of the switching tube control circuit (specifically the A / D2 port of the single-chip microcomputer in Figures 5 to 7 ) through the eighth resistor R4, realizing current sampling and feedback.

[0080] Preferably, as Figure 4 shown, the power supply further includes:

[0081] A first voltage sampling circuit, the input end of the first voltage sampling circuit is electrically connected to the output end of the first power output circuit, and the output end of the first voltage sampling circuit is electrically connected to the second signal input end of the switching tube control circuit;

[0082] A second voltage sampling circuit, the input end of the second voltage sampling circuit is electrically connected to the output end of the second power output circuit, and the output end of the second voltage sampling circuit is electrically connected to the third signal input end of the switching tube control circuit.

[0083] The input end of the first voltage sampling circuit is electrically connected to the output end of the first power supply output circuit, and the output end of the first power supply output circuit is electrically connected to the first load to output voltage to the first load. Therefore, the load voltage of the first load can be grasped in real time through the first voltage sampling circuit. Similarly, the load voltage of the second load can be grasped in real time through the second voltage sampling circuit. The first load voltage and the second load voltage are respectively fed back to the switching tube control circuit through the first voltage sampling circuit and the second voltage sampling circuit, and feedback regulation is implemented on the switching tube, so that the voltages of the dual loads can be stabilized at the corresponding target voltages (i.e., the first target voltage and the second target voltage), ensuring the stability of the entire power supply. Among them, when the first load voltage and the second load voltage are respectively fed back to the switching tube control circuit, the switching tube control circuit adjusts the PWM signal, and then adjusts the duty cycle of the MOS tube Q1, so that the first load and the second load are respectively at the corresponding target voltages.

[0084] Preferably, as Figures 5 to 7 shown, the first voltage sampling circuit includes a third capacitor C4, a second resistor R1, a third resistor R3, and a fourth resistor R6;

[0085] The first end of the second resistor R1 is electrically connected to the output end of the first power supply output circuit, 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 second 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 second signal input end of the switching tube control circuit, and the second end of the third capacitor C4 is grounded;

[0086] And / or, as Figures 5 to 7 shown, the second voltage sampling circuit includes a fourth capacitor C9, a fifth resistor R7, a sixth resistor R8, and a seventh resistor R9;

[0087] The first end of the fifth resistor R7 is electrically connected to the output end of the second power supply output circuit, and the second end of the fifth resistor R7 is grounded through the seventh resistor R9; the first end of the sixth resistor R8 is connected to the common connection end between the second end of the fifth resistor R7 and the seventh resistor R9, and the second end of the sixth resistor R8 is electrically connected to the third signal input end of the switching tube control circuit; the first end of the fourth capacitor C9 is connected to the common connection end between the second end of the sixth resistor R8 and the third signal input end of the switching tube control circuit, and the second end of the fourth capacitor C9 is grounded.

[0088] In the first voltage sampling circuit of 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 connected to the second signal input end of the switch tube control circuit (i.e., Figures 5 to 7 the A / D1 port of the single-chip microcomputer in

[0089] ), to realize the sampling and feedback of the first load voltage. The same applies to the second voltage sampling circuit, which will not be elaborated here.

[0090] 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. The specific details will not be elaborated here. The single-chip microcomputer can select a suitable specification or product model according to the actual situation.

[0091] 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 fall within the scope defined by the appended claims.

Claims

1. A dual-output power supply, characterized in that, The power supply includes a transformer, a primary circuit, a first power output circuit, a second power output circuit, a switch control circuit, and a switch; The primary circuit is disposed on the primary side of the transformer, and the transformer is electrically connected to an external power supply through the primary circuit; the first power output circuit is disposed on the secondary side of the transformer, the input end of the first power output circuit is electrically connected to the secondary side of the transformer, and the output end of the first power output circuit is electrically connected to an external first load; the second power output circuit is disposed on the primary side of the transformer, the input end of the second power output circuit is electrically connected to the primary side of the transformer, and the output end of the second power output circuit is electrically connected to an external second load; 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 primary side of the transformer and the input end of the second power output circuit.

2. The dual-output power supply according to claim 1, wherein The transformer includes a primary winding and a secondary winding; The primary circuit includes a first polarized capacitor C1 and a first capacitor C2; The same-named 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-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; The non-same-named end of the primary winding is electrically connected to both the output end of the switch and the input end of the second power output circuit.

3. The dual-output power supply according to claim 2, wherein The first power output circuit includes a first diode D1, a second polarized capacitor C6, and a second capacitor C3; The same-named end of the secondary winding is coupled to the same-named end of the primary winding, the non-same-named end of the secondary winding is coupled to the non-same-named end of the primary winding, and the non-same-named end of the secondary winding is also grounded; The same-named end of the secondary winding is also electrically connected to the first load through the first diode D1; the positive electrode of the second polarized capacitor C6 and the first end of the second capacitor C3 are both connected to a common connection end between the first diode D1 and the first load, and the negative electrode of the second polarized capacitor C6 and the second end of the second capacitor C3 are both grounded.

4. The dual-output power supply according to claim 2, wherein The second power output circuit includes a second diode D2, a third polarized capacitor C8, and a third capacitor C7; The positive electrode of the second diode D2 is electrically connected to the non-same-named end of the primary winding, the negative electrode of the second diode D2 is electrically connected to the second load; the positive electrode of the third polarized capacitor C8 and the first end of the third capacitor C7 are both connected to a common connection end between the negative electrode of the second diode D2 and the second load, and the negative electrode of the third polarized capacitor C8 and the second end of the third capacitor C7 are both grounded.

5. The dual-output power supply according to claim 2, 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 non-homonymous end of the primary winding and the input end of the second power output circuit.

6. The dual-output power supply according to claim 5, wherein The power supply further includes: A current sampling circuit, the input end of which is electrically connected to the source of the MOS transistor Q1, and the output end of which is electrically connected to the first signal input end of the switching transistor control circuit.

7. The dual-output power supply according to claim 6, characterized in that, The current sampling circuit includes a fifth capacitor C5, an eighth resistor R4, and a ninth resistor R5. The first end of the ninth resistor R5 is electrically connected to the source of the MOS transistor Q1, and the second end of the ninth resistor R5 is grounded. The first end of the eighth resistor R4 is connected to the common connection end between the first end of the ninth resistor R5 and the source of the MOS transistor Q1, and the second end of the eighth resistor R4 is electrically connected to the first signal input end of the switching transistor control circuit. The first end of the fifth capacitor C5 is connected to the common connection end between the second end of the eighth resistor R4 and the first signal input end of the switching transistor control circuit, and the second end of the fifth capacitor C5 is grounded.

8. The dual-output power supply according to claim 1, characterized in that, The power supply further includes: A first voltage sampling circuit, the input end of which is electrically connected to the output end of the first power output circuit, and the output end of which is electrically connected to the second signal input end of the switching transistor control circuit. A second voltage sampling circuit, the input end of which is electrically connected to the output end of the second power output circuit, and the output end of which is electrically connected to the third signal input end of the switching transistor control circuit.

9. The dual-output power supply according to claim 8, wherein, The first 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 end of the first power output circuit, 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 second signal input end 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 second signal input end of the switching transistor control circuit, and the second end of the third capacitor C4 is grounded. And / or, the second voltage sampling circuit includes a fourth capacitor C9, a fifth resistor R7, a sixth resistor R8, and a seventh resistor R9. The first end of the fifth resistor R7 is electrically connected to the output end of the second power supply output circuit, and the second end of the fifth resistor R7 is grounded through the seventh resistor R9; the first end of the sixth resistor R8 is connected to the common connection end between the second end of the fifth resistor R7 and the seventh resistor R9, and the second end of the sixth resistor R8 is electrically connected to the third signal input end of the switch control circuit; the first end of the fourth capacitor C9 is connected to the common connection end between the second end of the sixth resistor R8 and the third signal input end of the switch control circuit, and the second end of the fourth capacitor C9 is grounded.

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