Multipath output power supply circuit

Abstract

The utility model discloses a multi-output power supply circuit, and relates to the technical field of power electronics, and the circuit comprises a power factor correction circuit which is used for carrying out the boost processing of an input voltage, and obtaining a boosted voltage; the power conversion circuit is connected with the power factor correction circuit and is used for performing power conversion on the boost voltage to obtain a first voltage; and the constant voltage output circuit is connected with the power conversion circuit and used for carrying out voltage and current division processing on the first voltage and outputting various different output voltages, and the scheme meets the multi-voltage output requirement existing in industrial application.

Description

TECHNICAL FIELD

[0001] The utility model relates to power electronics technical field, specifically related to a kind of multi-output power supply circuit. BACKGROUND

[0002] With the progress of science and technology, power electronics technology also develops rapidly, especially switching power supply technology, switching power supply has become one of the indispensable electrical accessories in industrial applications, and in the current industrial applications, multiple or multiple switching power supplies are usually used.

[0003] But the voltage output of these power supplies is relatively single, mostly single-voltage output and low efficiency, and the reliability is not high, cannot meet the multiple-voltage output demand existing in part industrial applications, and the applicability is lower, so an urgent need for a kind of switching power supply capable of realizing multiple-voltage output. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of multi-output power supply circuit, to be able to realize the output of multiple different voltages, meet the demand of multiple-voltage output.

[0005] To achieve the above object, the utility model provides a kind of multi-output power supply circuit, comprising:

[0006] Power factor correction circuit is used to boost the input voltage and obtain the boost voltage;

[0007] Power conversion circuit, power conversion circuit is connected with power factor correction circuit, is used to power conversion to boost voltage and obtain the first voltage;

[0008] Constant voltage output circuit, constant voltage output circuit is connected with power conversion circuit, is used to divide voltage and current to the first voltage and output multiple different output voltages.

[0009] In another embodiment, the power conversion circuit includes:

[0010] Power conversion primary side circuit is used to power conversion to boost voltage and obtain the first voltage.

[0011] In another embodiment, the power conversion circuit further includes:

[0012] Power conversion primary side drive circuit is connected with power conversion primary side circuit, is used to drive and control power conversion primary side circuit.

[0013] In another embodiment, the power conversion primary side drive circuit includes:

[0014] Starting power supply and working state indicating circuit, starting power supply and working state indicating circuit are used to indicate the starting state of power supply and the working state of circuit.

[0015] In another embodiment, the multi-output power supply circuit further comprises:

[0016] a feedback circuit, the feedback circuit being connected to the constant-voltage output circuit and the power conversion primary-side driving circuit respectively;

[0017] The feedback circuit is configured to feed back the output voltage of the constant-voltage output circuit to the power conversion primary-side driving circuit.

[0018] In another embodiment, the multi-output power supply circuit further comprises:

[0019] a power factor correction control circuit, the power factor correction control circuit being connected to the power factor correction circuit and the power conversion primary-side driving circuit respectively;

[0020] The power factor correction control circuit is configured to drive and protect the power factor correction circuit and the power conversion primary-side driving circuit.

[0021] In another embodiment, the power factor correction control circuit comprises:

[0022] a soft-start circuit, the soft-start circuit being configured to achieve slow establishment of voltage.

[0023] In another embodiment, the multi-output power supply circuit further comprises:

[0024] a rectification filter circuit, the rectification filter circuit being connected to the power factor correction circuit and configured to rectify input alternating current into pulsating direct current as an input voltage input to the power factor correction circuit.

[0025] In another embodiment, the multi-output power supply circuit further comprises:

[0026] an electromagnetic interference filter circuit, the electromagnetic interference filter circuit being connected to the rectification filter circuit and configured to filter electromagnetic interference in the voltage.

[0027] In another embodiment, the multi-output power supply circuit further comprises:

[0028] an overvoltage protection circuit, the overvoltage protection circuit being connected to the electromagnetic interference filter circuit, the overvoltage protection circuit being configured to be fused when the voltage exceeds a rated value, thereby protecting the entire multi-output power supply circuit.

[0029] The multi-output power supply circuit has the following advantages:

[0030] The multi-output power supply circuit in the utility model, can utilize power factor correction circuit to the input voltage first boost processing, get boost voltage, utilize power conversion circuit to boost voltage power conversion again, get first voltage, finally utilize constant voltage output circuit to first voltage voltage division and shunt processing, output many different output voltages, namely the circuit in the utility model realizes to single input voltage processing, output many different voltage effect, satisfies the multi-voltage output demand existing in industrial application.

[0031] The above description is only a summary of the technical scheme of the utility model, in order to more clearly understand the technical means of the utility model, and can be implemented according to the content of the specification, the following preferred embodiments of the utility model are described in detail below with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a structure block diagram of a multi-output power supply circuit shown in an embodiment of the application;

[0033] Figure 2 It is a circuit diagram of a power factor correction circuit shown in an embodiment of the application;

[0034] Figure 3 It is a circuit diagram of a power conversion primary side circuit shown in an embodiment of the application;

[0035] Figure 4 It is a circuit diagram of a power conversion primary side drive circuit shown in an embodiment of the application;

[0036] Figure 5 It is a circuit diagram of a constant voltage output circuit shown in an embodiment of the application;

[0037] Figure 6 It is a circuit diagram of a starting power supply and working state indicating circuit shown in an embodiment of the application;

[0038] Figure 7 It is a circuit diagram of a feedback circuit shown in an embodiment of the application;

[0039] Figure 8 It is a circuit diagram of a power factor correction control circuit shown in an embodiment of the application;

[0040] Figure 9 It is a circuit diagram of a slow starting circuit shown in an embodiment of the application;

[0041] Figure 10 It is a circuit diagram of a rectification filter circuit shown in an embodiment of the application;

[0042] Figure 11This is a circuit diagram of an electromagnetic interference filtering circuit according to an embodiment of this application;

[0043] Figure 12 This is a circuit diagram of an overvoltage protection circuit according to an embodiment of this application;

[0044] Figure 13 This is a circuit diagram of a multi-output power supply circuit according to an embodiment of this application. Detailed Implementation

[0045] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0046] It should be noted that references to "an embodiment," "embodiment," "example embodiment," etc., in this specification refer to the described embodiment including specific features, structures, or characteristics; however, not every embodiment must include these specific features, structures, or characteristics. Furthermore, such expressions do not refer to the same embodiment. Moreover, when describing specific features, structures, or characteristics in conjunction with embodiments, whether or not explicitly described, it is indicated that incorporating such features, structures, or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0047] Furthermore, certain terms are used in the specification and subsequent claims to refer to specific components or parts. Those skilled in the art will understand that manufacturers may use different names or terms to refer to the same component or part. This specification and subsequent claims do not distinguish components or parts by differences in name, but rather by differences in function. The terms "comprising" and "including" used throughout the specification and subsequent claims are open-ended and should be interpreted as "including but not limited to." Additionally, the term "connection" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connections made through other means.

[0048] In one embodiment, see Figure 1The application provides a structural diagram of a multi-output power supply circuit, which comprises a power factor correction circuit, a power conversion circuit, a constant voltage output circuit and a constant current output circuit.

[0049] Specifically, referring to Figure 2 The main function of the power factor correction circuit is to raise the voltage at the C5 end to 370V through a BOOST voltage raising circuit composed of L2, Q1, D2 and C6, and to form a voltage sampling resistor by connecting R4, R58 and R59 in parallel, and R3 is a discharge resistor of a driving circuit.

[0050] The power conversion circuit comprises a power conversion primary side circuit and a power conversion primary side driving circuit.

[0051] Referring to Figure 3 The power conversion primary side circuit is mainly composed of a transformer T1 and an NMOS, the 5th pin of the transformer T1 is connected with a PFC output HVBUS, the 7th pin is connected with a D pole of a MOS, an RCD peak absorption circuit is connected in parallel between the 5th pin and the 7th pin of the transformer T1, a transformer circuit is composed of ZR1, R5, C7 and D3, the S pole of Q2 is connected with voltage sampling resistors R7 and R8, R7 and R8 are connected in parallel and then connected with a high side ground, the 1st pin of Q2 is connected with a high side ground through a discharge resistor R6, the 9th pin and the 10th pin of T1 are auxiliary power coils, and a power supply VDD for U1 and U3 is provided after the coils are rectified, filtered and stabilized through D4, C8, C9, R9 and ZR3.

[0052] Referring to Figure 4 The power conversion primary side driving circuit is mainly composed of a functional chip U1 and a peripheral circuit PWM generator for driving Q2 and a transformer. The chip can realize the characteristics required by an AC / DC or DC / DC fixed frequency voltage mode control scheme by using UC3844 or UC3845, has a 30V, 1A, 500KHz voltage mode PWM controller with a 50% duty cycle, a temperature range of 0 DEG C to 70 DEG C, and realizes stable and reliable control by using the least external elements.

[0053] The power conversion circuit comprises a power conversion primary side circuit and a power conversion primary side driving circuit. Figure 4The 1 foot of U1 is the error amplifier compensation pin, connect external compensation components to this pin to modify the error amplifier output, the error amplifier has voltage limit internally, therefore, the user can control zero duty cycle by forcing COMP to GROUND through external C11 and R13 to chip 2 foot, the 2 foot of U1 is the inverting input of internal error amplifier, VFB is used to control the power converter voltage feedback loop for stability, the 3 foot of U1 is the primary side current sense pin, connected to the current sense resistor, the current sense signal is converted to voltage signal through R28, C16, R26, C14 to input 3 foot, PWM uses this signal to terminate the conduction of the output switch, the voltage ramp can be applied to this pin to run the device in voltage mode control configuration, the 4 foot of U1 is the fixed frequency oscillator set point, connect timing resistor R24 to VREF and timing capacitor C12 to GROUND from this pin to set the switching frequency, the 5 foot of U1 is the power ground, connected to the main loop high side ground GND1, the 6 foot of U1 is the drive signal output, output by R25 gate resistor to the 1 foot of Q2, the 7 foot of U1 is the power supply, this foot is powered by start-up power VDD1 and supply power VDD, start-up power VDD1 is input after filtering by C13, C15, supply power VDD is input to 7 foot through D7, R57, D7 is an isolation diode, the power supply sequence of the two powers is that VDD1 provides 7.8-8.4V voltage during start-up, U1 outputs PWM wave to drive Q1 and transformer after start-up, the auxiliary power output stable 15V voltage VDD after the transformer works, the 8 foot of U1 is 5V reference voltage, VREF is used to provide charging current to the oscillator timing capacitor through the timing resistor.

[0054] Referring to Figure 5 The transformer secondary coil 11, 12 feet in the constant voltage output circuit are rectified by Schottky diodes D17, D18, C24 and R42 are connected in series and then connected in parallel across the diodes to form an RC reverse spike absorption circuit, C25, C26, L4, C27, C28 form a Π-shaped filter circuit, R43 and C29 form an RC filter circuit, and R44 is the output dead load, which is the first output, with an output voltage of 24V and a current of 2A.

[0055] The transformer secondary coil 13, 14, 15 feet are the second and third outputs, with an output voltage of ±15V and a current of 1A.

[0056] The transformer 13, 15 feet diode constitutes a full-wave rectifier circuit, 14 feet for the center point is also the positive and negative power supply common end, U5 is a three-terminal voltage regulator L7915, U6 is a three-terminal voltage regulator L7815, transformer 13 feet through rectifier diode D11 rectification, C32, C34, R51 filter to the 1 foot of L7815, the 2 foot of L7815 is connected to the common end, the 3 foot is filtered through C37, C39 and outputs +15V voltage.

[0057] The transformer 13, 15 feet diode constitutes a full-wave rectifier circuit, 14 feet for the center point is also the positive and negative power supply common end, U5 is a three-terminal voltage regulator L7915, U6 is a three-terminal voltage regulator L7815, transformer 13 feet through rectifier diode D11 rectification, C32, C34, R51 filter to the 1 foot of L7815, the 2 foot of L7815 is connected to the common end, the 3 foot is filtered through C37, C39 and outputs +15V voltage.

[0058] The transformer 13, 15 feet diode constitutes a full-wave rectifier circuit, 14 feet for the center point is also the positive and negative power supply common end, U5 is a three-terminal voltage regulator L7915, U6 is a three-terminal voltage regulator L7815, transformer 13 feet through rectifier diode D11 rectification, C32, C34, R51 filter to the 1 foot of L7815, the 2 foot of L7815 is connected to the common end, the 3 foot is filtered through C37, C39 and outputs +15V voltage.

[0059] The transformer 13, 15 feet diode constitutes a full-wave rectifier circuit, 14 feet for the center point is also the positive and negative power supply common end, U5 is a three-terminal voltage regulator L7915, U6 is a three-terminal voltage regulator L7815, transformer 13 feet through rectifier diode D11 rectification, C32, C34, R51 filter to the 1 foot of L7815, the 2 foot of L7815 is connected to the common end, the 3 foot is filtered through C37, C39 and outputs +15V voltage.

[0060] The transformer 13, 15 feet diode constitutes a full-wave rectifier circuit, 14 feet for the center point is also the positive and negative power supply common end, U5 is a three-terminal voltage regulator L7915, U6 is a three-terminal voltage regulator L7815, transformer 13 feet through rectifier diode D11 rectification, C32, C34, R51 filter to the 1 foot of L7815, the 2 foot of L7815 is connected to the common end, the 3 foot is filtered through C37, C39 and outputs +15V voltage.

[0061] The multi-output power supply circuit in the above embodiment can first utilize the power factor correction circuit to perform boost processing on the input voltage to obtain a boosted voltage, then utilize the power conversion circuit to perform power conversion on the boosted voltage to obtain a first voltage, and finally utilize the constant voltage output circuit to perform voltage division and current division processing on the first voltage to output multiple different output voltages, that is, the circuit in the utility model realizes the effect of processing a single input voltage and outputting multiple different voltages, and meets the multiple voltage output demand existing in industrial applications.

[0062] In another embodiment, the power conversion primary side drive circuit comprises: a starting power supply and working state indication circuit, which is used for indicating the starting state of the power supply and the working state of the circuit.

[0063] Specifically, referring to Figure 6 , the starting power supply and the working state indication circuit, the power supply VIN1 is connected with R18, R19, R20, R21, R22, Z1 and Q6 to form a starting power supply voltage stabilizing circuit, and the stabilized voltage is equal to the voltage between Z1, which is about 13V. R60, R61, R62 and D19 are connected in series to form an HVBUS voltage indication circuit, D19 is a red LED diode, and D19 emits red light when HVBUS voltage is normal. R54 and D10 form an output 24V working indication lamp, D10 is a green LED diode, and D19 emits green light when the output 24V voltage is normal.

[0064] The setting of the starting power supply and the working state indication circuit in the above embodiment can help the operation and maintenance personnel to know the working state of the entire multi-output power supply circuit at any time.

[0065] In another embodiment, the multi-output power supply circuit further comprises a feedback circuit, the feedback circuit is connected with the constant voltage output circuit and the power conversion primary side driving circuit respectively; the feedback circuit is used for feeding back the output voltage of the constant voltage output circuit to the power conversion primary side driving circuit.

[0066] Specifically, referring to Figure 7 , the feedback circuit samples the voltage at the output VCC point, and U2 optocoupler and U4 are used as TL431 three-terminal adjustable voltage stabilizer to realize voltage feedback and adjust PWM duty cycle to realize constant voltage. If the VCC voltage is set to 24V, 2.5V voltage is obtained through the series connection of R47, R48 and R49 to control the second pin of U4, the first pin of U4 is connected with the second pin of U2, and the third pin of U4 is connected with the ground. If the voltage is higher than 24V, the voltage at the second pin of U4 will be higher than 2.5V, the first pin and the third pin of U4 will be turned on, the second pin of U2 connected with U4 will be connected with the ground through R45, the primary light emitting diode of U4 will work, the secondary 3 and 4 pins will be turned on, and the output voltage VFB will be equal to the REF 5V voltage. The controller U1 adjusts the output PWM duty cycle, and the duty cycle is adjusted to be small until the output voltage is less than or equal to 24V. If the voltage is less than 24V, U2 and U4 do not work, the voltage at the VFB point is less than 2.5V, the controller U1 adjusts the output PWM duty cycle, and the duty cycle is adjusted to be large. Thus, the constant voltage output is realized through repeated work.

[0067] The above feedback circuit can feed back the output voltage of the constant voltage output circuit, thereby ensuring the stability of the output voltage.

[0068] In another embodiment, the multi-output power supply circuit further comprises a power factor correction control circuit, the power factor correction control circuit is connected with the power factor correction circuit and the power conversion primary side driving circuit respectively; the power factor correction control circuit is used for driving and protecting the power factor correction circuit and the power conversion primary side driving circuit.

[0069] Specifically, referring to Figure 8 , the main function of the power factor correction control circuit is to drive Q1 to output a suitable duty ratio PWM wave according to the voltage at the C5, C6 end and the voltage passing through Q1 to ensure that the voltage at the C6 end is 370V, and the circuit mainly consists of a functional chip U3 and peripheral circuits. The 1 pin of U3 is the inverting terminal input of the error amplifier, the C6 end voltage HVBUS is input to the 1 pin of U3 through R31, R32, R33, R34 and R35 as the target control voltage, the 2 pin of U3 is the output of the error amplifier, and the negative feedback circuit is composed of C20 and R63 returning to the 1 pin of U3, the 3 pin of U3 is the input of the multiplier, and the voltage at the C5 end is sent to the 3 pin through a voltage dividing circuit composed of R36, R38, R39 and C21, the 4 pin of U3 is the voltage sampling input, the voltage is converted into a voltage input by using the voltage detection resistor R40, the 5 pin of U3 is the zero current detection, the auxiliary winding of the BOOST inductor L2 is directly input to the 5 pin through R37 and C62, the 6 pin of U3 is the power supply ground, connected to the main loop high side ground GND1, the 7 pin of U3 is the drive signal output, output to the 1 pin of Q1 by the R41 gate resistance, and the 8 pin of U3 is the power supply, and the power supply VDD is sent to the 8 pin after being filtered by C22 and C23.

[0070] In another embodiment, the power factor correction control circuit comprises: a soft start circuit, the soft start circuit is used to realize slow establishment of voltage.

[0071] Specifically, referring to Figure 9 , when the power supply is powered on, the VFB output voltage in the block 9 is equal to the REF point voltage, the controller U1 outputs the minimum duty ratio, with the passage of time, the voltage across C18 rises, the VFB output voltage is less than 2.5V, the controller U1 adjusts the output duty ratio, and the duty ratio is adjusted to be high. At this time, the VFB point voltage is fed back by the light coupling auxiliary side VFB point voltage, and the block 9 mainly consists of a voltage dividing circuit composed of D16, R13, R11, R12, R10, R14 and C18. The slow voltage establishment is realized by controlling the conduction and turn-off of Q3 and Q4 through the charging of the C18 capacitor, so as to complete the soft start function.

[0072] The soft start circuit in the above embodiment delays the starting speed of the circuit, plays a role in protecting the circuit, and increases the service life of the circuit.

[0073] In another embodiment, the multi-output power supply circuit further comprises: a rectifier filter circuit, the rectifier filter circuit is connected with the power factor correction circuit, and is used to rectify the input alternating current into pulsating direct current as an input voltage input to the power factor correction circuit.

[0074] Specifically, referring to Figure 10The main function of the rectifier filter circuit is to rectify the AC power from the mains into pulsating DC through D1, and to filter the pulsating DC into smooth DC voltage through R2 and C5, wherein R2 is a thermistor connected in series between D1 and C5 to prevent D1 from being damaged when charging C5, because the voltage of the capacitor cannot change abruptly, C5 is equivalent to a short circuit at the charging moment, the greater the voltage through R2, the higher the resistance of R2 will change from low resistance to high resistance, and when the voltage decreases, the resistance will return to the original value, thereby completing the charging of the capacitor at the power-on moment, and the voltage at the C5 end after charging is 220x1.414=311V.

[0075] In another embodiment, the multi-output power supply circuit further comprises an electromagnetic interference filter circuit connected with the rectifier filter circuit, for filtering electromagnetic interference in the voltage.

[0076] Specifically, referring to Figure 11 The main functions of the electromagnetic interference filter circuit are two-fold: one is to filter electromagnetic interference from the power grid, and the other is to prevent electromagnetic interference from the body from affecting other electrical equipment on the power grid. The circuit mainly consists of C1, L1, C2, C3 and C4, wherein C1, L1 and C2 form a differential mode interference suppression circuit, and C3 and C4 are used to filter common mode interference.

[0077] In another embodiment, the multi-output power supply circuit further comprises an overvoltage protection circuit connected with the electromagnetic interference filter circuit, the overvoltage protection circuit being used to fuse when the voltage exceeds the rated value, thereby protecting the entire multi-output power supply circuit.

[0078] Specifically, referring to Figure 12 The overvoltage protection circuit mainly consists of a fuse F1 connected in series with the L phase and a varistor R1 connected in parallel with the L and N terminals. When the input voltage is higher than a certain voltage, R1 changes from high resistance to low resistance, and the current through F1 exceeds the rated value, causing F1 to fuse and disconnect the circuit from the input, thereby achieving overvoltage hardware protection.

[0079] In another embodiment, referring to Figure 13 , the circuit diagram of the entire multi-output power supply circuit, the specific functions are described above and will not be repeated here,

[0080] The technical features of the above embodiments can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not contradict, they should be considered as within the scope of the present disclosure.

[0081] The above embodiments only express several implementation manners of the utility model, the description is more specific and detailed, but can not therefore be understood as the limitation of the utility model patent range. It should be pointed out that for ordinary skilled person in the art, without departing from the utility model concept, several modifications and improvements can be made, which belong to the protection range of the utility model. Therefore, the protection range of the utility model patent should be subject to the appended claims.

Claims

1. A multiple output power supply circuit, characterized by comprising: The multi-output power supply circuit comprises: a power factor correction circuit for boosting an input voltage to obtain a boosted voltage; a power conversion circuit connected to the power factor correction circuit for converting the boosted voltage to obtain a first voltage; a constant voltage output circuit connected to the power conversion circuit for dividing and distributing the first voltage to output a plurality of different output voltages.

2. The multiple output power supply circuit of claim 1, wherein, The power conversion circuit comprises: a power conversion primary side circuit for converting the boosted voltage to obtain a first voltage.

3. The multiple output power supply circuit of claim 2, wherein, The power conversion circuit further comprises: a power conversion primary side driving circuit connected to the power conversion primary side circuit for driving and controlling the power conversion primary side circuit.

4. The multiple output power supply circuit of claim 3, wherein, The power conversion primary side driving circuit comprises: a start-up power supply and working state indication circuit for indicating the start-up state of the power supply and the working state of the circuit.

5. The multiple output power supply circuit of claim 4, wherein, The multi-output power supply circuit further comprises: a feedback circuit connected to the constant voltage output circuit and the power conversion primary side driving circuit respectively; the feedback circuit is configured to feed back the output voltage of the constant voltage output circuit to the power conversion primary side driving circuit.

6. The multiple output power supply circuit of claim 1, wherein, The multi-output power supply circuit further comprises: a power factor correction control circuit connected to the power factor correction circuit and the power conversion primary side driving circuit respectively; the power factor correction control circuit is configured to drive and protect the power factor correction circuit and the power conversion primary side driving circuit.

7. The multiple output power supply circuit of claim 6, wherein, The power factor correction control circuit comprises: a slow start-up circuit for slowly establishing the voltage.

8. The multiple output power supply circuit of claim 1, wherein, The multi-output power supply circuit further comprises: a rectification and filtering circuit connected to the power factor correction circuit for rectifying the input alternating current into pulsating direct current as the input voltage input to the power factor correction circuit.

9. The multiple output power supply circuit of claim 8, wherein, The multi-output power supply circuit further comprises: an electromagnetic interference filtering circuit connected to the rectification and filtering circuit for filtering out the electromagnetic interference in the voltage.

10. The multiple output power supply circuit of claim 9, wherein, The multi-output power supply circuit further comprises: an overvoltage protection circuit connected to the electromagnetic interference filtering circuit, the overvoltage protection circuit being configured to be fused when the voltage exceeds the rated value to protect the entire multi-output power supply circuit.

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