A multi-output flyback power supply

Abstract

The utility model discloses a kind of multi-output flyback power supply, it is related to switching power supply technical field.Its main technical scheme: the input end of first rectification filter module is connected with the first output end of transformer in reference module, the output end of first rectification filter module is connected with the input end of feedback sampling circuit unit in reference module;The input end of counterweight stable resistance module is connected with the output end of first rectification filter module, the output end of counterweight stable module is connected with PGND;The input end of second rectification filter module is connected with the second output end of transformer in reference module, the output end of second rectification filter module is connected with 12V+ of reference module, 12V- is connected with;The input end of third rectification filter module is connected with the first output end of transformer in reference module, the output end of third rectification filter module is connected with DSP12V+ of reference module, DSP_PGND is connected with.Reach the purpose of effectively reducing the risk of excessive internal sharp peak pulse, and then improve electromagnetic capacity, reduce the risk of affecting normal use of equipment.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of switching power supply, specifically relates to a multi-output flyback power supply. BACKGROUND

[0002] The existing multi-output flyback power supply adopts multiple closed-loop sampling, and in use, the power output by the load is randomly distributed, which makes the internal sharp pulse too large, the electromagnetic capacity deteriorates, and finally affects the normal use of the equipment. UTILITY MODEL CONTENTS

[0003] The utility model discloses a multi-output flyback power supply, which solves the problem that the existing multi-output flyback power supply in use, the power output by the load is randomly distributed, which makes the internal sharp pulse too large, the electromagnetic capacity deteriorates, and finally affects the normal use of the equipment.

[0004] To solve the above technical problems, the utility model adopts the following technical scheme:

[0005] A multi-output flyback power supply, comprising a first rectifier filter module, a counterweight stabilizing resistor module, a second rectifier filter module and a third rectifier filter module, the input end of the first rectifier filter module is used to be connected with the first output end of the transformer in the reference module, and the output end of the first rectifier filter module is used to be connected with the input end of the feedback sampling circuit unit in the reference module; the input end of the counterweight stabilizing resistor module is connected with the output end of the first rectifier filter module, and the output end of the counterweight stabilizing module is connected with PGND; the input end of the second rectifier filter module is used to be connected with the second output end of the transformer in the reference module, and the output end of the second rectifier filter module is used to be connected with 12V+ and 12V- of the reference module; the input end of the third rectifier filter module is used to be connected with the first output end of the transformer in the reference module, and the output end of the third rectifier filter module is used to be connected with DSP12V+ and DSP_PGND of the reference module.

[0006] Further technical solutions are: the first rectification filtering module includes a capacitor C10, a capacitor C14, a capacitor C18, a first rectification unit D16, a second rectification unit D17, a resistor R15, an electrolytic capacitor EC1 and an electrolytic capacitor EC2; one end of the capacitor C18, the No. 1 pin of the first rectification unit D16, the No. 3 pin of the first rectification unit D16, the No. 1 pin of the second rectification unit D17, the No. 3 pin of the second rectification unit D17 are used for being connected with the No. 14 pin of the transformer in the reference module; the other end of the capacitor C18 is connected with one end of the resistor R15; the other end of the resistor R15 is connected with the No. 2 pin of the first rectification unit D16, the No. 2 pin of the second rectification unit D17, the positive electrode of the electrolytic capacitor EC1, one end of the capacitor C10, the positive electrode of the electrolytic capacitor EC2, the first end of the capacitor C14, the input end of the counterweight stable resistance module; the positive electrode of the electrolytic capacitor EC2 is used for being connected with 26V+ of the reference module; the negative electrode of the electrolytic capacitor EC1 is used for being connected with the No. 13 pin of the transformer in the reference module; the negative electrode of the electrolytic capacitor EC1, the other end of the capacitor C10, the negative electrode of the electrolytic capacitor EC2, the other end of the capacitor C14 are all PGND.

[0007] Further technical solutions are: the counterweight stable resistance module includes a resistor R17, a resistor R19, a resistor R28, a resistor R20, a resistor R16 and a resistor R77; one end of the resistor R17, one end of the resistor R19, one end of the resistor R28, one end of the resistor R20, one end of the resistor R16 and one end of the resistor R77 are all connected with the other end of the resistor R15; the other end of the resistor R17, the other end of the resistor R19, the other end of the resistor R28, the other end of the resistor R20, the other end of the resistor R16 and the other end of the resistor R77 are all connected with PGND; wherein, PGND is used for being connected with DSP_PGND of the reference module.

[0008] Further technical solutions are: the second rectification filter module includes a first rectification filter unit and a second rectification filter unit; the first rectification filter unit includes a diode D4, an electrolytic capacitor EC3, an electrolytic capacitor EC5, a capacitor C8, a capacitor C11, a capacitor C68, an inductor L7 and a voltage stabilizing chip U7; the voltage stabilizing chip U7 is 7812; the positive electrode of the diode D4 is used to be connected with the No. 12 pin of the transformer in the reference module; the negative electrode of the diode D4 is connected with the positive electrode of the electrolytic capacitor EC3, one end of the inductor L7 and one end of the capacitor C8; the other end of the inductor L7 is connected with one end of the capacitor C68 and the No. 1 pin of the voltage stabilizing chip U7; the No. 3 pin of the voltage stabilizing chip U7 is connected with one end of the capacitor C11 and the positive electrode of the electrolytic capacitor EC5, and the No. 3 pin of the voltage stabilizing chip U7 is used to be connected with 12V+ of the reference module; the negative electrode of the electrolytic capacitor EC3 is used to be connected with the No. 11 pin of the transformer in the reference module; the negative electrode of the electrolytic capacitor EC3, the other end of the diode C8, the other end of the diode C68, the No. 2 pin of the voltage stabilizing chip U7, the other end of the capacitor C11 and the negative electrode of the electrolytic capacitor EC5 are all connected with AGND; wherein AGND is used to be connected with DSP_PGND of the reference module; the input end of the second rectification filter unit is used to be connected with the second output end of the transformer in the reference module, and the input end of the second rectification filter unit is connected with the negative electrode of the electrolytic capacitor EC3; the output end of the second rectification filter unit is used to be connected with 12V- of the reference module.

[0009] Further technical solutions are: the second rectification filter unit includes a diode D5, an electrolytic capacitor EC4, an electrolytic capacitor EC6, a capacitor C9, a capacitor C12, a capacitor C69, an inductor L8 and a negative voltage regulator U4; the negative voltage regulator U4 is 7912; the positive electrode of the diode D5 is used to be connected with the No. 10 pin of the transformer in the reference module; the negative electrode of the diode D5 is connected with the negative electrode of the electrolytic capacitor EC3, the positive electrode of the electrolytic capacitor EC4, one end of the capacitor C9, one end of the capacitor C69, the No. 1 pin of the negative voltage regulator U4, one end of the capacitor C12 and the positive electrode of the electrolytic capacitor EC6; the negative electrode of the electrolytic capacitor EC4 is used to be connected with the No. 9 pin of the transformer in the reference module; the negative electrode of the electrolytic capacitor EC4 is connected with the other end of the capacitor C9 and one end of the inductor L8; the other end of the inductor L8 is connected with the other end of the capacitor C69 and the No. 2 pin of the negative voltage regulator U4; the No. 3 pin of the negative voltage regulator U4 is connected with the other end of the capacitor C12 and the negative electrode of the electrolytic capacitor EC6, and the No. 3 pin of the negative voltage regulator U4 is used to be connected with 12V- of the reference module.

[0010] Further technical solutions are: the third rectifier filter module includes diode D8, resistance R78, electrolytic capacitor EC10, capacitor C13, capacitor C48 and inductor L1; the positive electrode of the diode D8 is connected with one end of the resistance R78, and the positive electrode of the diode D8 is used for connecting with the No. 8 pin of the transformer in the reference module; the negative electrode of the diode D8 is connected with the positive electrode of the electrolytic capacitor EC10, one end of the capacitor C13 and one end of the inductor L1; the other end of the inductor L1 is connected with one end of the capacitor C48, and the other end of the inductor L1 is used for connecting with DSP12V+ of the reference module; the other end of the resistance R78 is connected with the negative electrode of the electrolytic capacitor EC10, the other end of the capacitor C13 and the other end of the capacitor C48, and the other end of the resistance R78 is used for connecting with DSP_PGND of the reference module.

[0011] Further technical solutions are: the multi-output flyback power supply further includes a mute module; the mute module includes a rectification sampling unit and a mute unit; the rectification sampling unit includes diode D6, diode D9, resistance R30, resistance R33, capacitor C37 and electrolytic capacitor C66; the positive electrode of the diode D6 is connected with the positive electrode of the diode D4; the negative electrode of the diode D6 is connected with the positive electrode of the diode D9; the negative electrode of the diode D9 is connected with one end of the resistance R33; the other end of the resistance R33 is connected with one end of the resistance R30, the positive electrode of the electrolytic capacitor C66, one end of the capacitor C37 and the input end of the mute unit; the other end of the resistance R30, the negative electrode of the electrolytic capacitor C66 and the other end of the capacitor C37 are all connected with AGND; the input end of the mute unit is connected with No. 3 pin of the voltage stabilizing chip U7; the output end of the mute unit is used for connecting with MCU_MUTE and AMP_MUTE of the reference module.

[0012] Further technical solutions are: the mute unit includes diode D7, diode D14, diode D18, resistor R21, resistor R22, resistor R23, resistor R24, resistor R25, resistor R50, resistor R51, electrolytic capacitor EC9, electrolytic capacitor C35, capacitor C32, capacitor C34, voltage stabilizing diode D10, voltage stabilizing diode D13, triode Q2 and triode Q3;The positive pole of the diode D14 is connected with the No. 3 pin of the voltage stabilizing chip U7;The negative pole of the diode D14 is connected with one end of the resistor R21 and the positive pole of the electrolytic capacitor EC9;The other end of the resistor R21 is connected with one end of the capacitor C32, the negative pole of the voltage stabilizing diode D10 and one end of the resistor R22;The negative pole of the electrolytic capacitor EC9, the other end of the capacitor C32 and the positive pole of the voltage stabilizing diode D10 are all connected with AGND;The other end of the resistor R22 is connected with the collector of the triode Q2, and the other end of the resistor R22 is used for being connected with AMP_MUTE of the reference module;The base of the triode Q2 is connected with the positive pole of the voltage stabilizing diode D13 and one end of the capacitor C34;The emitter of the triode Q2 is connected with the other end of the capacitor C34 and is all connected with AGND;The negative pole of the voltage stabilizing diode D13 is connected with one end of the resistor R23 and the emitter of the triode Q3;The other end of the resistor R23 is connected with one end of the resistor R24, one end of the resistor R25 and the positive pole of the electrolytic capacitor C35;The other end of the resistor R24 is connected with the negative pole of the diode D18;The positive pole of the diode D18, one end of the resistor R50 and the negative pole of the diode D7 are all connected with the other end of the resistor R33;The negative pole of the electrolytic capacitor C35 and the other end of the resistor R25 are all connected with AGND;The other end of the resistor R50, the positive pole of the diode D7 and one end of the resistor R51 are all connected with the base of the triode Q3;The base of the triode Q3 is used for being connected with MCU_MUTE of the reference module;The collector of the triode Q3 and the other end of the resistor R51 are all connected with AGND.

[0013] Compared with the prior art, the utility model has the advantages of:

[0014] In use, the risk of random allocation of load output power is effectively reduced, the risk of excessive internal peak pulse is effectively reduced, electromagnetic capacity is improved, and the risk of affecting normal use of equipment is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is an electrical block diagram of the multi-output flyback power supply in the embodiment;

[0016] Figure 2 It is a circuit structure topology graph of the first rectifier filter module of the multi-output flyback power supply in the embodiment.

[0017] Figure 3 This is a circuit topology diagram of a second rectifier and filter module for a multi-output flyback power supply in this embodiment.

[0018] Figure 4 This is a circuit topology diagram of a third rectifier and filter module for a multi-output flyback power supply in this embodiment.

[0019] Figure 5 This is a circuit topology diagram of a silent module for a multi-output flyback power supply in this embodiment;

[0020] Figure 6 The circuit topology diagram is for a portion of the circuitry of the existing reference module.

[0021] Figure 7 This is a circuit topology diagram for another part of the existing reference module.

[0022] The attached diagram shows the markings and corresponding component names:

[0023] 100 - First rectifier and filter module; 200 - Counterweight stabilizing resistor module; 300 - Second rectifier and filter module; 400 - Third rectifier and filter module. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] Example

[0026] This embodiment provides a multi-output flyback power supply, such as... Figure 1 As shown, the system includes a first rectifier and filter module 100, a counterweight stabilizing resistor module 200, a second rectifier and filter module 300, and a third rectifier and filter module 400. The input terminal of the first rectifier and filter module 100 is connected to the first output terminal of the transformer in the reference module, and the output terminal of the first rectifier and filter module 100 is connected to the input terminal of the feedback sampling circuit unit in the reference module. The input terminal of the counterweight stabilizing resistor module 200 is connected to the output terminal of the first rectifier and filter module 100, and the output terminal of the counterweight stabilizing resistor module is connected to PGND. The input terminal of the second rectifier and filter module 300 is connected to the second output terminal of the transformer in the reference module, and the output terminal of the second rectifier and filter module 300 is connected to both 12V+ and 12V- of the reference module. The input terminal of the third rectifier and filter module 400 is connected to the first output terminal of the transformer in the reference module, and the output terminal of the third rectifier and filter module 400 is connected to both DSP12V+ and DSP_PGND of the reference module.

[0027] like Figure 2As shown in the figure, in the embodiment, the first rectification and filtering module 100 includes a capacitor C10, a capacitor C14, a capacitor C18, a first rectification unit D16, a second rectification unit D17, a resistor R15, an electrolytic capacitor EC1, and an electrolytic capacitor EC2; one end of the capacitor C18, pin 1 of the first rectification unit D16, pin 3 of the first rectification unit D16, pin 1 of the second rectification unit D17, pin 3 of the second rectification unit D17 are all used for being connected with pin 14 of the transformer in the reference module; the other end of the capacitor C18 is connected with one end of the resistor R15; the other end of the resistor R15 is connected with pin 2 of the first rectification unit D16, pin 2 of the second rectification unit D17, the positive electrode of the electrolytic capacitor EC1, one end of the capacitor C10, the positive electrode of the electrolytic capacitor EC2, the first end of the capacitor C14, and the input end of the counterweight stable resistance module 200; the positive electrode of the electrolytic capacitor EC2 is used for being connected with 26V+ of the reference module; the negative electrode of the electrolytic capacitor EC1 is used for being connected with pin 13 of the transformer in the reference module; the negative electrode of the electrolytic capacitor EC1, the other end of the capacitor C10, the negative electrode of the electrolytic capacitor EC2, and the other end of the capacitor C14 are all PGND.

[0028] As shown in the figure, Figure 2 As shown in the figure, in the embodiment, the counterweight stable resistance module 200 includes a resistor R17, a resistor R19, a resistor R28, a resistor R20, a resistor R16, and a resistor R77; one end of the resistor R17, one end of the resistor R19, one end of the resistor R28, one end of the resistor R20, one end of the resistor R16, and one end of the resistor R77 are all connected with the other end of the resistor R15; the other end of the resistor R17, the other end of the resistor R19, the other end of the resistor R28, the other end of the resistor R20, the other end of the resistor R16, and the other end of the resistor R77 are all PGND; wherein, PGND is used for being connected with DSP_PGND of the reference module.

[0029] As shown in the figure, Figure 3As shown in the figure, in this embodiment, the second rectification filtering module 300 comprises a first rectification filtering unit and a second rectification filtering unit; the first rectification filtering unit comprises a diode D4, an electrolytic capacitor EC3, an electrolytic capacitor EC5, a capacitor C8, a capacitor C11, a capacitor C68, an inductor L7 and a voltage stabilizing chip U7; the voltage stabilizing chip U7 is 7812; the positive pole of the diode D4 is used for being connected with the No. 12 pin of the transformer in the reference module; the negative pole of the diode D4 is connected with the positive pole of the electrolytic capacitor EC3, one end of the inductor L7 and one end of the capacitor C8; the other end of the inductor L7 is connected with one end of the capacitor C68 and the No. 1 pin of the voltage stabilizing chip U7; the No. 3 pin of the voltage stabilizing chip U7 is connected with one end of the capacitor C11 and the positive pole of the electrolytic capacitor EC5, and the No. 3 pin of the voltage stabilizing chip U7 is used for being connected with 12V+ of the reference module; the negative pole of the electrolytic capacitor EC3 is used for being connected with the No. 11 pin of the transformer in the reference module; the negative pole of the electrolytic capacitor EC3, the other end of the diode C8, the other end of the diode C68, the No. 2 pin of the voltage stabilizing chip U7, the other end of the capacitor C11 and the negative pole of the electrolytic capacitor EC5 are all connected with AGND; wherein AGND is used for being connected with DSP_PGND of the reference module; the input end of the second rectification filtering unit is used for being connected with the second output end of the transformer in the reference module, and the input end of the second rectification filtering unit is connected with the negative pole of the electrolytic capacitor EC3; the output end of the second rectification filtering unit is used for being connected with 12V- of the reference module.

[0030] As shown in the figure, Figure 3 As shown in the figure, in this embodiment, the second rectification filtering unit comprises a diode D5, an electrolytic capacitor EC4, an electrolytic capacitor EC6, a capacitor C9, a capacitor C12, a capacitor C69, an inductor L8 and a negative voltage regulator U4; the negative voltage regulator U4 is 7912; the positive pole of the diode D5 is used for being connected with the No. 10 pin of the transformer in the reference module; the negative pole of the diode D5 is connected with the negative pole of the electrolytic capacitor EC3, the positive pole of the electrolytic capacitor EC4, one end of the capacitor C9, one end of the capacitor C69, the No. 1 pin of the negative voltage regulator U4, one end of the capacitor C12 and the positive pole of the electrolytic capacitor EC6; the negative pole of the electrolytic capacitor EC4 is used for being connected with the No. 9 pin of the transformer in the reference module; the negative pole of the electrolytic capacitor EC4 is connected with the other end of the capacitor C9 and one end of the inductor L8; the other end of the inductor L8 is connected with the other end of the capacitor C69 and the No. 2 pin of the negative voltage regulator U4; the No. 3 pin of the negative voltage regulator U4 is connected with the other end of the capacitor C12 and the negative pole of the electrolytic capacitor EC6, and the No. 3 pin of the negative voltage regulator U4 is used for being connected with 12V- of the reference module.

[0031] As shown in the figure, Figure 4As shown in the figure, in the embodiment, the third rectification filtering module 400 includes a diode D8, a resistor R78, an electrolytic capacitor EC10, a capacitor C13, a capacitor C48 and an inductor L1; the positive electrode of the diode D8 is connected with one end of the resistor R78, and the positive electrode of the diode D8 is used for being connected with the No. 8 pin of the transformer in the reference module; the negative electrode of the diode D8 is connected with the positive electrode of the electrolytic capacitor EC10, one end of the capacitor C13 and one end of the inductor L1; the other end of the inductor L1 is connected with one end of the capacitor C48, and the other end of the inductor L1 is used for being connected with the DSP12V+ of the reference module; the other end of the resistor R78 is connected with the negative electrode of the electrolytic capacitor EC10, the other end of the capacitor C13 and the other end of the capacitor C48, and the other end of the resistor R78 is used for being connected with the DSP_PGND of the reference module.

[0032] As shown in the figure, Figure 5 As shown in the figure, in the embodiment, the multi-output flyback power supply further includes a mute module; the mute module includes a rectification sampling unit and a mute unit; the rectification sampling unit includes a diode D6, a diode D9, a resistor R30, a resistor R33, a capacitor C37 and an electrolytic capacitor C66; the positive electrode of the diode D6 is connected with the positive electrode of the diode D4; the negative electrode of the diode D6 is connected with the positive electrode of the diode D9; the negative electrode of the diode D9 is connected with one end of the resistor R33; the other end of the resistor R33 is connected with one end of the resistor R30, the positive electrode of the electrolytic capacitor C66, one end of the capacitor C37 and the input end of the mute unit; the other end of the resistor R30, the negative electrode of the electrolytic capacitor C66 and the other end of the capacitor C37 are all connected with AGND; the input end of the mute unit is connected with the No. 3 pin of the voltage stabilizing chip U7; the output end of the mute unit is used for being connected with the MCU_MUTE and the AMP_MUTE of the reference module.

[0033] As shown in the figure, Figure 5As shown, in the embodiment, the mute unit includes diode D7, diode D14, diode D18, resistor R21, resistor R22, resistor R23, resistor R24, resistor R25, resistor R50, resistor R51, electrolytic capacitor EC9, electrolytic capacitor C35, capacitor C32, capacitor C34, voltage stabilizing diode D10, voltage stabilizing diode D13, triode Q2 and triode Q3; the positive pole of the diode D14 is connected with the No. 3 pin of the voltage stabilizing chip U7; the negative pole of the diode D14 is connected with one end of the resistor R21 and the positive pole of the electrolytic capacitor EC9; the other end of the resistor R21 is connected with one end of the capacitor C32, the negative pole of the voltage stabilizing diode D10 and one end of the resistor R22; the negative pole of the electrolytic capacitor EC9, the other end of the capacitor C32 and the positive pole of the voltage stabilizing diode D10 are all connected with AGND; the other end of the resistor R22 is connected with the collector of the triode Q2, and the other end of the resistor R22 is used for being connected with AMP_MUTE of the reference module; the base of the triode Q2 is connected with the positive pole of the voltage stabilizing diode D13 and one end of the capacitor C34; the emitter of the triode Q2 is connected with the other end of the capacitor C34; the negative pole of the voltage stabilizing diode D13 is connected with one end of the resistor R23 and the emitter of the triode Q3; the other end of the resistor R23 is connected with one end of the resistor R24, one end of the resistor R25 and the positive pole of the electrolytic capacitor C35; the other end of the resistor R24 is connected with the negative pole of the diode D18; the positive pole of the diode D18, one end of the resistor R50 and the negative pole of the diode D7 are all connected with the other end of the resistor R33; the negative pole of the electrolytic capacitor C35 and the other end of the resistor R25 are all connected with AGND; the other end of the resistor R50, the positive pole of the diode D7 and one end of the resistor R51 are all connected with the base of the triode Q3; the base of the triode Q3 is used for being connected with MCU_MUTE of the reference module; the collector of the triode Q3 and the other end of the resistor R51 are all connected with AGND.

[0034] The multi-output flyback power supply provided by the embodiment has the working principle as follows:

[0035] Figure 6 and Figure 7For the prior art reference module, the No. 13 pin and the No. 14 pin of the transformer are main circuit coils, current flows out from the No. 14 pin of the transformer, is rectified by the first rectifying unit D16 and the second rectifying unit D17, is filtered by the electrolytic capacitor EC1 and the electrolytic capacitor EC2, and forms 26V+ direct current. The 26V+ direct current is fed back to the switching power supply U1 after passing through the feedback sampling unit in the reference module, and the switching power supply U1 processes the corresponding sampling signal. The feedback sampling unit is composed of the resistor R41, the resistor R42, the resistor R43, the resistor R44, the resistor R45, the resistor R18 and the voltage stabilizer U3.

[0036] When the voltage is high, the duty cycle of the output of the switching power supply U1 is adjusted, so that the effective value of the output voltage of the No. 13 pin and the No. 14 pin of the transformer is reduced; when the voltage is low, the duty cycle of the output of the switching power supply U1 is adjusted, so that the effective value of the output voltage of the No. 13 pin and the No. 14 pin of the transformer is increased.

[0037] The No. 11 pin and the No. 12 pin of the transformer in the reference module are the first secondary coil, current flows out from the No. 12 pin of the transformer, is rectified by the diode D4, is filtered by the electrolytic capacitor EC3, the inductor L7 and the capacitor C68, and is then stabilized by the voltage stabilizing chip U7 to form a positive 12V+ voltage output.

[0038] The No. 9 pin and the No. 10 pin of the transformer in the reference module are the second secondary coil, current flows out from the No. 10 pin of the transformer, is rectified by the diode D5, is filtered by the electrolytic capacitor EC4, the inductor L8 and the capacitor C69, and is then stabilized by the negative voltage regulator U4 to form a 12V- voltage output.

[0039] The No. 8 pin and the No. 11 pin of the transformer in the reference module are the third secondary coil, current flows out from the No. 8 pin of the transformer, is rectified by the diode D8, is filtered by the electrolytic capacitor EC10, the inductor L1 and the capacitor C48, and outputs DSP12V+ to provide a preliminary power supply voltage for the DSP.

[0040] The power supply of the No. 9 pin and the No. 12 pin of the transformer in the reference module does not have a feedback sampling unit for the switching power supply U1. In use, the risk of random allocation of load output power is effectively reduced, the risk of excessive internal sharp pulse is effectively reduced, the electromagnetic capacity is improved, and the risk of affecting the normal use of the equipment is reduced.

[0041] At the same time, because the power supply of the No. 9 pin and the No. 12 pin of the transformer in the reference module does not have a feedback sampling unit for the switching power supply U1, the second rectifying and filtering module 300 is in an open-loop state, and there is a floating value when the output voltage is output. Therefore, in the present embodiment, the multi-output flyback power supply adopts the voltage stabilizing chip U7 and the negative voltage regulator U4 to stabilize the output voltage of the second rectifying and filtering module 300.

[0042] When the positive electrode 26V+ power supply of the electrolytic capacitor EC2 is empty, and the use load current of at least one of the 12V+, 12V- and DSP12V+ power supplies is greater than a certain value, the voltage of the corresponding pin of the transformer will be pulled down, and when it is pulled down to a certain value, the switching power supply U1 will mistakenly think it is an inter-electrode short circuit, and start the current protection circuit to turn off the power supply. Among them, the certain value can be an empirical value, and can also be preset according to the actual use of the multi-output flyback power supply, so it is not described again. Therefore, in the multi-output flyback power supply in the embodiment, the output end of the first rectifier filter module 100 is connected with a counterweight stabilizing resistance module 200 composed of resistors R17, R19, R28, R20, R16 and R77, to serve as the load of the positive electrode 26V+ power supply of the electrolytic capacitor EC2.

[0043] Among them, the calculation method of the resistance value in the counterweight stabilizing resistance module 200;

[0044] P=(U*U) / R

[0045] Among them, P is the sum of the power required by the second rectifier filter module 300 and the power required by the third rectifier filter module 400; U is the positive electrode output of the electrolytic capacitor EC2; R is the resistance value of the resistance in the counterweight stabilizing resistance module 200. For example, the second rectifier filter module 300 requires a power of 0.8W, the third rectifier filter module 400 requires a power of 0.2W, and the positive electrode output of the electrolytic capacitor EC2 is 26V+ power supply. The resistance value R of the counterweight stabilizing resistance module 200 is 676 ohms.

[0046] Among them, the resistance in the counterweight stabilizing resistance module 200 adopts a power resistor to achieve the purpose of reducing the risk of resistance damage. And the rated power of the resistance in the counterweight stabilizing resistance module 200 is greater than 2-3 times the actual rated power, to achieve the purpose of reducing the heating temperature of the resistance. For example, the counterweight stabilizing resistance module 200 of the multi-output flyback power supply in the embodiment adopts six 3.3K patch 2512 resistors in parallel, with a total of 6W. The resistance value is 550 ohms, and the counterweight stabilizing power is 1.2W.

[0047] Diode D6, diode D9, resistor R30, resistor R33, capacitor C37 and electrolytic capacitor C66 constitute the rectification sampling unit of the mute module. Since the capacity of electrolytic capacitor C66 is 10uF, which is much smaller than the voltage of the first rectification filter module 100, the counterweight stable resistance module 200, the second rectification filter module 300 and the third rectification filter module 400, the electrolytic capacitor C66 discharges the fastest. Resistor R24 and resistor R25 are a series voltage dividing circuit, and resistor R24, resistor R25 and electrolytic capacitor C35 constitute a power-on delay circuit. Among them, the length of the charging time is determined by the resistance value of resistor R24 and resistor R25, the fixed ratio of the resistance value of resistor R24 and resistor R25, and the capacity value of electrolytic capacitor C35. For example, the ratio of the resistance value of resistor R24 and resistor R25 is R24 / R25=33K / 18K=1.83, if you want to prolong the charging time, you can replace R24 with 100K. At this time, resistor R25=100K / 1.83=54.6K. At the same time, the capacity value of C35 can also be increased.

[0048] When the voltage of the positive electrode of electrolytic capacitor C35 is greater than 3.1V, stable diode D13 is turned on, and triode Q2 is turned on. At this time, the voltage of the collector (C) of triode Q2 changes from 5V to 0V. The controlled circuit is turned on, and the controlled circuit works (the controlled power IC is high level mute effective). Diode D18 is used for reverse blocking electrolytic capacitor C35 discharge when the machine is turned off.

[0049] Resistor R50, resistor R51 and triode Q3 constitute the Q2 conduction circuit for turning off the mute. The voltage divided by resistor R50 and resistor R51 makes the voltage of the base (B) of triode Q3 greater than the voltage divided by resistor R24 and resistor R25. That is, (R24 / R25)<(R50 / R51). Further, after turning on, triode Q3 is cut off and not turned on.

[0050] The running process of the mute module is:

[0051] When the power is on, the collector (C) of the triode Q2 is high level, and the control circuit is not working. The current output from the No. 12 pin of the transformer in the reference module passes through the rectification sampling unit composed of diode D6, diode D9, resistor R33, resistor R30, capacitor C66 and capacitor C37, and then outputs direct current. The direct current is divided into two paths, one of which is divided by resistor R50 and resistor R51, and then supplied to the triode Q3 to make the triode Q3 reverse-biased and not conductive. The other path is divided by diode D18, resistor R24 and resistor R25, and then charges the electrolytic capacitor C35. When the charging voltage of the electrolytic capacitor C35 reaches 3.1V, the voltage stabilizing diode D13 is turned on, making the triode Q2 forward saturated and conductive, and the voltage of the collector (C) of the triode Q2 is 0. At this time, the controlled power amplifier works, and the triode Q3 is still in the reverse cut-off state because the voltage of the collector (C) of the triode Q3 is lower than that of the base (B) of the triode Q3.

[0052] When the power is off, the voltage of the No. 12 pin of the transformer in the reference module decreases, and the voltage of the rectification sampling unit composed of diode D6, diode D9, resistor R33, resistor R30, capacitor C66 and capacitor C37 also decreases, making the voltage of the base (B) of the triode Q3 decrease. At the same time, the diode D18 is reverse blocked, making the voltage of the base (B) of the triode Q3 decrease faster. At this time, the triode Q3 is turned on, and the collector (C) of the triode Q3 is short-circuited to the ground. At the same time, the voltage of the electrolytic capacitor C35 is transmitted to the ground through the protection resistor R23 and the triode Q3. The voltage of the base (B) of the triode Q2 is 0, and the triode Q2 is cut off and not conductive. The voltage of the collector (C) of the triode Q2 increases, and the controlled power amplifier does not work. Due to the small capacity of the electrolytic capacitor C66 compared with the capacities of the electrolytic capacitors EC1, EC2, EC3, EC4, EC5, EC6 and EC10, the remaining circuits are still in working state except the controlled power amplifier. When the voltage of the base (B) of the triode Q3 is pulled down by the MCU, the remaining circuits are still in working state except the controlled power amplifier.

[0053] Among them, the diode D14 provides a bias voltage for the mute pin AMP_MUTE of the power IC, and reversely blocks the discharge of the electrolytic capacitor EC9 when the power is off, thereby achieving the purpose of controlling the power IC with voltage.

[0054] While the present application has been described with reference to the numerous explanatory embodiments thereof, it is to be understood that various other modifications can be effected within the scope of the application, as described in the claims. More specifically, many variations and modifications will be apparent to those skilled in the art from the description and drawings herein, given the benefit of the description, drawings and claims as a whole. Other uses will be apparent to those skilled in the art.

Claims

1. A multi-output flyback power supply, characterized by, Comprise: The first rectifier filter module (100), the input end of the first rectifier filter module (100) is used for connecting with the first output end of the transformer in the reference module, the output end of the first rectifier filter module (100) is used for connecting with the input end of the feedback sampling circuit unit in the reference module; The counterweight stable resistance module (200), the input end of the counterweight stable resistance module (200) is connected with the output end of the first rectifier filter module (100), and the output end of the counterweight stable module is connected with PGND; The second rectifier filter module (300), the input end of the second rectifier filter module (300) is used for connecting with the second output end of the transformer in the reference module, and the output end of the second rectifier filter module (300) is used for connecting with 12V+ and 12V- of the reference module; The third rectifier filter module (400), the input end of the third rectifier filter module (400) is used for connecting with the first output end of the transformer in the reference module, and the output end of the third rectifier filter module (400) is used for connecting with DSP12V+ and DSP_PGND of the reference module.

2. The multi-output flyback power supply according to claim 1, wherein: The first rectifier filter module (100) comprises a capacitor C10, a capacitor C14, a capacitor C18, a first rectifier unit D16, a second rectifier unit D17, a resistor R15, an electrolytic capacitor EC1 and an electrolytic capacitor EC2; One end of the capacitor C18, pin 1 of the first rectifier unit D16, pin 3 of the first rectifier unit D16, pin 1 of the second rectifier unit D17, pin 3 of the second rectifier unit D17 are all used for connecting with pin 14 of the transformer in the reference module; The other end of the capacitor C18 is connected with one end of the resistor R15; The other end of the resistor R15 is connected with pin 2 of the first rectifier unit D16, pin 2 of the second rectifier unit D17, the positive electrode of the electrolytic capacitor EC1, one end of the capacitor C10, the positive electrode of the electrolytic capacitor EC2, the first end of the capacitor C14, the input end of the counterweight stable resistance module (200); The positive electrode of the electrolytic capacitor EC2 is used for connecting with 26V+ of the reference module; The negative electrode of the electrolytic capacitor EC1 is used for connecting with pin 13 of the transformer in the reference module; The negative electrode of the electrolytic capacitor EC1, the other end of the capacitor C10, the negative electrode of the electrolytic capacitor EC2, the other end of the capacitor C14 are all PGND.

3. The multi-output flyback power supply according to claim 2, wherein: The counterweight stable resistance module (200) comprises a resistor R17, a resistor R19, a resistor R28, a resistor R20, a resistor R16 and a resistor R77; One end of the resistor R17, one end of the resistor R19, one end of the resistor R28, one end of the resistor R20, one end of the resistor R16 and one end of the resistor R77 are all connected with the other end of the resistor R15. The other end of the resistor R17, the other end of the resistor R19, the other end of the resistor R28, the other end of the resistor R20, the other end of the resistor R16, and the other end of the resistor R77 are all connected to PGND. The PGND is used for connecting with the DSP_PGND of the reference module.

4. The multi-output flyback power supply of claim 3, characterized in that: The second rectification and filtering module (300) comprises a first rectification and filtering unit and a second rectification and filtering unit. The first rectification and filtering unit comprises a diode D4, an electrolytic capacitor EC3, an electrolytic capacitor EC5, a capacitor C8, a capacitor C11, a capacitor C68, an inductor L7, and a voltage stabilizing chip U7. The voltage stabilizing chip U7 is 7812. The positive pole of the diode D4 is used for connecting with the No. 12 pin of the transformer in the reference module. The negative pole of the diode D4 is connected with the positive pole of the electrolytic capacitor EC3, one end of the inductor L7, and one end of the capacitor C8. The other end of the inductor L7 is connected with one end of the capacitor C68 and the No. 1 pin of the voltage stabilizing chip U7. The No. 3 pin of the voltage stabilizing chip U7 is connected with one end of the capacitor C11 and the positive pole of the electrolytic capacitor EC5, and the No. 3 pin of the voltage stabilizing chip U7 is used for connecting with 12V+ of the reference module. The negative pole of the electrolytic capacitor EC3 is used for connecting with the No. 11 pin of the transformer in the reference module. The negative pole of the electrolytic capacitor EC3, the other end of the diode C8, the other end of the diode C68, the No. 2 pin of the voltage stabilizing chip U7, the other end of the capacitor C11, and the negative pole of the electrolytic capacitor EC5 are all connected to AGND. The AGND is used for connecting with the DSP_PGND of the reference module. The input end of the second rectification and filtering unit is used for connecting with the second output end of the transformer in the reference module, and the input end of the second rectification and filtering unit is connected with the negative pole of the electrolytic capacitor EC3. The output end of the second rectification and filtering unit is used for connecting with 12V- of the reference module.

5. The multi-output flyback power supply of claim 4, characterized in that: The second rectification and filtering unit comprises a diode D5, an electrolytic capacitor EC4, an electrolytic capacitor EC6, a capacitor C9, a capacitor C12, a capacitor C69, an inductor L8, and a negative voltage regulator U4. The negative voltage regulator U4 is 7912. The positive pole of the diode D5 is used for connecting with the No. 10 pin of the transformer in the reference module. The negative pole of the diode D5 is connected with the negative pole of the electrolytic capacitor EC3, the positive pole of the electrolytic capacitor EC4, one end of the capacitor C9, one end of the capacitor C69, the No. 1 pin of the negative voltage regulator U4, one end of the capacitor C12, and the positive pole of the electrolytic capacitor EC6. The negative pole of the electrolytic capacitor EC4 is used for connecting with the No. 9 pin of the transformer in the reference module. The negative pole of the electrolytic capacitor EC4 is connected with the other end of the capacitor C9 and one end of the inductor L8. The other end of the inductor L8 is connected with the other end of the capacitor C69 and the No. 2 pin of the negative voltage regulator U4. The pin 3 of the negative voltage regulator U4 is connected with the other end of the capacitor C12, the negative electrode of the electrolytic capacitor EC6, and is used for connecting with the 12V- of the reference module.

6. The multi-output flyback power supply of claim 5, wherein: The third rectification filter module (400) comprises a diode D8, a resistor R78, an electrolytic capacitor EC10, a capacitor C13, a capacitor C48 and an inductor L1; The positive electrode of the diode D8 is connected with one end of the resistor R78, and is used for connecting with the pin 8 of the transformer in the reference module; The negative electrode of the diode D8 is connected with the positive electrode of the electrolytic capacitor EC10, one end of the capacitor C13 and one end of the inductor L1; The other end of the inductor L1 is connected with one end of the capacitor C48, and is used for connecting with the DSP12V+ of the reference module; The other end of the resistor R78 is connected with the negative electrode of the electrolytic capacitor EC10, the other end of the capacitor C13 and the other end of the capacitor C48, and is used for connecting with the DSP_PGND of the reference module.

7. The multi-output flyback power supply of claim 6, wherein: It further comprises a mute module; The mute module comprises a rectification sampling unit and a mute unit; The rectification sampling unit comprises a diode D6, a diode D9, a resistor R30, a resistor R33, a capacitor C37 and an electrolytic capacitor C66; The positive electrode of the diode D6 is connected with the positive electrode of the diode D4; The negative electrode of the diode D6 is connected with the positive electrode of the diode D9; The negative electrode of the diode D9 is connected with one end of the resistor R33; The other end of the resistor R33 is connected with one end of the resistor R30, the positive electrode of the electrolytic capacitor C66, one end of the capacitor C37 and the input end of the mute unit; The other end of the resistor R30, the negative electrode of the electrolytic capacitor C66 and the other end of the capacitor C37 are all connected with AGND; The input end of the mute unit is connected with the pin 3 of the voltage stabilizing chip U7; The output end of the mute unit is used for connecting with the MCU_MUTE and the AMP_MUTE of the reference module.

8. The multi-output flyback power supply of claim 7, wherein: The mute unit comprises a diode D7, a diode D14, a diode D18, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R50, a resistor R51, an electrolytic capacitor EC9, an electrolytic capacitor C35, a capacitor C32, a capacitor C34, a voltage stabilizing diode D10, a voltage stabilizing diode D13, a triode Q2 and a triode Q3; The positive electrode of the diode D14 is connected with the pin 3 of the voltage stabilizing chip U7; The negative electrode of the diode D14 is connected with one end of the resistor R21 and the positive electrode of the electrolytic capacitor EC9; The other end of the resistor R21 is connected with one end of the capacitor C32, the negative electrode of the voltage stabilizing diode D10 and one end of the resistor R22; The negative electrode of the electrolytic capacitor EC9, the other end of the capacitor C32 and the positive electrode of the voltage stabilizing diode D10 are all connected to AGND; The other end of the resistor R22 is connected to the collector of the triode Q2, and the other end of the resistor R22 is used to be connected to AMP_MUTE of the reference module; The base of the triode Q2 is connected to the positive electrode of the voltage stabilizing diode D13 and one end of the capacitor C34; The emitter of the triode Q2 is connected to the other end of the capacitor C34; The negative electrode of the voltage stabilizing diode D13 is connected to one end of the resistor R23 and the emitter of the triode Q3; The other end of the resistor R23 is connected to one end of the resistor R24, one end of the resistor R25 and the positive electrode of the electrolytic capacitor C35; The other end of the resistor R24 is connected to the negative electrode of the diode D18; The positive electrode of the diode D18, one end of the resistor R50 and the negative electrode of the diode D7 are all connected to the other end of the resistor R33; The negative electrode of the electrolytic capacitor C35 and the other end of the resistor R25 are both connected to AGND; The other end of the resistor R50, the positive electrode of the diode D7 and one end of the resistor R51 are all connected to the base of the triode Q3; The base of the triode Q3 is used to be connected to MCU_MUTE of the reference module; The collector of the triode Q3 and the other end of the resistor R51 are both connected to AGND.

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