Auxiliary power supply device for independent drive board

Abstract

The utility model discloses an auxiliary power supply device for an independent drive board, which belongs to the technical field of power supplies, comprises a rectifier, a main voltage stabilizer, an auxiliary power supply, a switching power supply circuit and a transformer unit, and solves the technical problem that the output voltage of a switching power supply fluctuates along with the rectifier in a working environment with large input voltage fluctuation. According to the utility model, the fluctuation of the input voltage can be effectively coped with, even if the input voltage of the external AC power supply changes, the system can still maintain stable power supply, the VCC voltage of UC3844 is ensured to be stable in the whole working process, the problem of unstable working caused by the voltage fluctuation is avoided, and the service life of the system is prolonged. According to the utility model, a multi-stage voltage stabilizer is adopted to supply power to the UC3844, so that the output of the switching power supply is stabilized, and an important role is played on the stability of load equipment.

Description

Technical Field

[0001] The utility model belongs to the technical field of power supply, and in particular relates to an independent driving plate auxiliary power supply device. Background Art

[0002] In many industrial applications, the stability of power supply is a key issue. Traditional switching power supply chips mostly use pulse width modulation (PWM) technology, which can effectively adjust the output voltage and achieve efficient power conversion. Its main functions include controlling the on-time and off-time of the switch tube to achieve precise control of the output voltage.

[0003] In the design of switching power supplies, ensuring stable power input is crucial to ensuring the stability of the output voltage. If the operating voltage of the switching power supply chip is unstable, especially when it is close to its undervoltage lockout voltage (such as UC3844), its internal reference voltage and oscillation frequency will be affected, and the internal circuit will work unstably, resulting in changes in switching frequency, unstable PWM signals, and output voltage fluctuations, thereby affecting the stability of the final output voltage and the overall performance of the power supply. Utility Model Content

[0004] The utility model aims to provide an independent driving board auxiliary power supply device, which solves the technical problem that the output voltage of the switching power supply fluctuates accordingly in a working environment where the input voltage fluctuates greatly.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An independent driving board auxiliary power supply device comprises a rectifier, a main voltage regulator, an auxiliary power supply, a switching power supply circuit and a transformer unit, wherein the input end of the rectifier is connected to an external power supply, the output end is connected to the input end of the main voltage regulator, the output end of the main voltage regulator is connected to the transformer unit, and the switching power supply circuit is respectively connected to the output end of the main voltage regulator and the transformer unit;

[0007] The input end of the auxiliary power supply is connected to the output end of the main voltage stabilizer, and the output end provides a working voltage for the switching power supply circuit.

[0008] Preferably, the rectifier includes a rectifier bridge B1, the main voltage regulator includes a voltage regulator IC1, a capacitor C1, a capacitor C3 and a capacitor C4, the transformer unit includes a transformer T1, pins 1 and 3 of the rectifier bridge are input ends of the rectifier, pins 2 and 4 are output ends of the rectifier, pins 1 and 3 of the rectifier bridge are connected to an external power supply, pin 2 is connected to the IN pin of the voltage regulator IC1, and pin 4 is connected to the ground wire;

[0009] The IN pin of the voltage regulator IC1 is also connected to the ground line through the capacitor C1, and the OUT pin is connected to the 1 pin of the transformer T1. The capacitors C3 and C4 are filter capacitors of the OUT pin of the voltage regulator IC1.

[0010] Preferably, the model of the voltage regulator IC1 is LM7824.

[0011] Preferably, the switching power supply circuit includes a power chip IC3, a capacitor C2, a capacitor C11, a resistor R1, a capacitor C5, a resistor R2, a resistor R4, a resistor R3, a diode D1, a resistor R7, a power switch tube Q1, a resistor R9, a capacitor C12, a resistor R8, a resistor R5, a capacitor C8, a diode D2, a resistor R6, a diode D3, a diode D4, a capacitor C9 and a capacitor C10, and a resistor R1 is connected between pins 4 and 8 of the power chip IC3, and pins 4 and 8 of the power chip IC3 are also connected to the ground wire through capacitors C2 and C11 respectively, and pin 5 of the power chip IC3 is connected to the ground wire, and pin 1 is connected to the ground wire through capacitors connected in parallel. C5 and resistor R2 are connected to pin 2 of power chip IC3, pin 2 of power chip IC3 is connected to OUT pin of voltage regulator IC1 through resistors R4 and R5 connected in series, pin 2 of power chip IC3 is also connected to ground through resistor R3, pin 6 of power chip IC3 is connected to G pole of power switch tube Q1 through resistor R7, S pole of power switch tube Q1 is connected to ground through resistor R9, D pole is connected to pin 2 of transformer T1, D pole of power switch tube Q1 is also connected to OUT pin of voltage regulator IC1 through resistor R6, cathode of diode D2 is connected to OUT pin of voltage regulator IC1 through capacitor C8, and anode is connected to D pole of power switch tube Q1;

[0012] Pin 3 of the power chip IC3 is connected to the S pole of the power switch tube Q1 through the resistor R8, and pin 3 HIA of the power chip IC3 is connected to the ground wire through the capacitor C12;

[0013] Pin 3 of transformer T1 is connected to the ground wire, pin 4 is connected to the positive electrode of diode D3, the negative electrode of diode D3 is connected to the positive electrode of diode D4, the negative electrode of diode D4 is connected to pin 2 of power chip IC3 through resistor R4, the negative electrode of diode D3 is connected to the ground wire through capacitor C9, and the negative electrode of diode D4 is connected to the ground wire through capacitor C10;

[0014] Pins 6 and 5 of the transformer T1 output the first power supply, and pins 8 and 7 output the second power supply.

[0015] Preferably, the model of the power chip IC3 is UC3844, and the power switch tube Q1 is a MOSFET tube.

[0016] Preferably, the auxiliary power supply includes a voltage regulator IC2, a capacitor C6 and a capacitor C7, the IN pin of the voltage regulator IC2 is connected to the OUT pin of the voltage regulator IC1, the OUT pin is connected to pin 7 of the power chip IC3, and the capacitors C6 and C7 are filter capacitors of the OUT pin of the voltage regulator IC2.

[0017] Preferably, the model of the voltage regulator IC2 is LM7816.

[0018] The utility model discloses an independent driver board auxiliary power supply device, which solves the technical problem that the output voltage of the switching power supply fluctuates in a working environment where the input voltage fluctuates greatly. The utility model can effectively cope with the fluctuation of the input voltage by using a rectifier, a main voltage stabilizer and an auxiliary power supply. Even if the input voltage of the external AC power supply changes, the system can still maintain a stable power supply. The auxiliary power supply of the utility model can provide a stable 16V voltage for UC3844 when the output voltage of the main voltage stabilizer fluctuates, ensuring that the VCC voltage of UC3844 remains stable during the entire working process, avoiding the problem of unstable operation due to voltage fluctuations. The utility model uses a multi-stage voltage stabilizer to power UC3844, stabilizes the output of the switching power supply, and plays an important role in the stability of the load equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic block diagram of the utility model;

[0020] Figure 2 It is a circuit diagram of the utility model. DETAILED DESCRIPTION

[0021] Depend on Figure 1-Figure 2 An independent driving board auxiliary power supply device shown includes a rectifier, a main voltage regulator, an auxiliary power supply, a switching power supply circuit and a transformer unit, wherein the input end of the rectifier is connected to an external power supply, the output end is connected to the input end of the main voltage regulator, the output end of the main voltage regulator is connected to the transformer unit, and the switching power supply circuit is respectively connected to the output end of the main voltage regulator and the transformer unit;

[0022] The rectifier includes a rectifier bridge B1, the main voltage regulator includes a voltage regulator IC1, a capacitor C1, a capacitor C3 and a capacitor C4, the transformer unit includes a transformer T1, pins 1 and 3 of the rectifier bridge are input ends of the rectifier, pins 2 and 4 are output ends of the rectifier, pins 1 and 3 of the rectifier bridge are connected to an external power supply, pin 2 is connected to the IN pin of the voltage regulator IC1, and pin 4 is connected to a ground wire;

[0023] In this embodiment, the input end of the rectifier bridge B1 is connected to an external transformer, and the external transformer is used to provide an external power supply. In this embodiment, LM7824 is used as a primary voltage regulator, and its input voltage is limited to a maximum of 40V.

[0024] The IN pin of the voltage regulator IC1 is also connected to the ground line through the capacitor C1, and the OUT pin is connected to the 1 pin of the transformer T1. The capacitors C3 and C4 are filter capacitors of the OUT pin of the voltage regulator IC1.

[0025] The switching power supply circuit includes a power chip IC3, a capacitor C2, a capacitor C11, a resistor R1, a capacitor C5, a resistor R2, a resistor R4, a resistor R3, a diode D1, a resistor R7, a power switch tube Q1, a resistor R9, a capacitor C12, a resistor R8, a resistor R5, a capacitor C8, a diode D2, a resistor R6, a diode D3, a diode D4, a capacitor C9 and a capacitor C10. The resistor R1 is connected between pins 4 and 8 of the power chip IC3. The pins 4 and 8 of the power chip IC3 are also connected to the ground wire through capacitors C2 and C11 respectively. The pin 5 of the power chip IC3 is connected to the ground wire, and the pin 1 is connected to the capacitor C5 connected in parallel. The resistor R2 is connected to the 2nd pin of the power chip IC3, the 2nd pin of the power chip IC3 is connected to the OUT pin of the voltage regulator IC1 through the resistor R4 and the resistor R5 connected in series, the 2nd pin of the power chip IC3 is also connected to the ground wire through the resistor R3, the 6th pin of the power chip IC3 is connected to the G pole of the power switch tube Q1 through the resistor R7, the S pole of the power switch tube Q1 is connected to the ground wire through the resistor R9, and the D pole is connected to the 2nd pin of the transformer T1, the D pole of the power switch tube Q1 is also connected to the OUT pin of the voltage regulator IC1 through the resistor R6, the cathode of the diode D2 is connected to the OUT pin of the voltage regulator IC1 through the capacitor C8, and the anode is connected to the D pole of the power switch tube Q1;

[0026] Pin 3 of the power chip IC3 is connected to the S pole of the power switch tube Q1 through the resistor R8, and pin 3 HIA of the power chip IC3 is connected to the ground wire through the capacitor C12;

[0027] Pin 3 of transformer T1 is connected to the ground wire, pin 4 is connected to the positive electrode of diode D3, the negative electrode of diode D3 is connected to the positive electrode of diode D4, the negative electrode of diode D4 is connected to pin 2 of power chip IC3 through resistor R4, the negative electrode of diode D3 is connected to the ground wire through capacitor C9, and the negative electrode of diode D4 is connected to the ground wire through capacitor C10;

[0028] Pins 6 and 5 of the transformer T1 output the first power supply, and pins 8 and 7 output the second power supply.

[0029] When the power is turned on, the power chip IC3 obtains the starting voltage and starts to oscillate. It controls the switch of the power switch tube Q1 through PWM modulation, thereby adjusting the current on the primary side of the transformer T1 and transferring energy to the secondary side through the transformer T1. The secondary side of the transformer T1 provides power supply for the subsequent circuits.

[0030] In this embodiment, UC3844 is used as the main switching power supply chip, and its minimum startup voltage is usually 16V. That is, when the voltage is lower than this value, the chip may not start normally or maintain normal operation. The undervoltage lockout voltage is usually 10V. In other words, when the VCC voltage drops to this level, the chip will enter the undervoltage lockout state and stop working until the voltage returns to the normal range.

[0031] When the external voltage fluctuates between 40V and 20V instantaneously (such as in the application environment of wind power, the input voltage is not stable enough), 20V or more is usually greater than the startup voltage and undervoltage lockout voltage. UC3844 should be able to work normally within this range. However, although 20V is higher than the undervoltage lockout voltage, it is close to this value, which will make UC3844 almost at the working boundary. The chip may cause the switching frequency to change and the PWM signal to be unstable due to the unstable operation of the internal circuit, resulting in the overall unstable operation of the chip. Specifically, the fluctuation of the output voltage may affect the stability of the entire power supply system. In order to solve the above problems, an auxiliary power supply is added as a secondary voltage regulator in this embodiment to provide a stable 16V voltage for UC3844 to ensure that UC3844 can work under a stable working voltage.

[0032] The input end of the auxiliary power supply is connected to the output end of the main voltage stabilizer, and the output end provides a working voltage for the switching power supply circuit.

[0033] The auxiliary power supply includes a voltage regulator IC2, a capacitor C6 and a capacitor C7. The IN pin of the voltage regulator IC2 is connected to the OUT pin of the voltage regulator IC1, and the OUT pin is connected to the 7th pin of the power chip IC3. The capacitors C6 and C7 are filter capacitors of the OUT pin of the voltage regulator IC2.

[0034] In this embodiment, the voltage regulator IC2 uses LM7816, and its input voltage is provided by the voltage regulator IC1 (LM7824). Its input voltage can be as low as 18V, which isolates the influence of input voltage fluctuation on UC3844 and greatly improves the output performance of the switching power supply.

[0035] The model of the voltage regulator IC1 is LM7824.

[0036] The model of the power chip IC3 is UC3844, and the power switch tube Q1 is a MOSFET tube.

[0037] The model of the voltage regulator IC2 is LM7816.

[0038] The utility model discloses an independent driver board auxiliary power supply device, which solves the technical problem that the output voltage of the switching power supply fluctuates in a working environment where the input voltage fluctuates greatly. The utility model can effectively cope with the fluctuation of the input voltage by using a rectifier, a main voltage stabilizer and an auxiliary power supply. Even if the input voltage of the external AC power supply changes, the system can still maintain a stable power supply. The auxiliary power supply of the utility model can provide a stable 16V voltage for UC3844 when the output voltage of the main voltage stabilizer fluctuates, ensuring that the VCC voltage of UC3844 remains stable during the entire working process, avoiding the problem of unstable operation due to voltage fluctuations. The utility model uses a multi-stage voltage stabilizer to power UC3844, stabilizes the output of the switching power supply, and plays an important role in the stability of the load equipment.

Claims

1. An independent drive board auxiliary power supply device, characterized in that: It includes a rectifier, a main voltage regulator, an auxiliary power supply, a switching power supply circuit and a transformer unit, wherein the input end of the rectifier is connected to an external power supply, the output end is connected to the input end of the main voltage regulator, the output end of the main voltage regulator is connected to the transformer unit, and the switching power supply circuit is respectively connected to the output end of the main voltage regulator and the transformer unit; The input end of the auxiliary power supply is connected to the output end of the main voltage stabilizer, and the output end provides a working voltage for the switching power supply circuit.

2. An independent drive board auxiliary power supply device as claimed in claim 1, characterized in that: The rectifier includes a rectifier bridge B1, the main voltage regulator includes a voltage regulator IC1, a capacitor C1, a capacitor C3 and a capacitor C4, the transformer unit includes a transformer T1, pins 1 and 3 of the rectifier bridge are input ends of the rectifier, pins 2 and 4 are output ends of the rectifier, pins 1 and 3 of the rectifier bridge are connected to an external power supply, pin 2 is connected to the IN pin of the voltage regulator IC1, and pin 4 is connected to a ground wire; The IN pin of the voltage regulator IC1 is also connected to the ground line through the capacitor C1, and the OUT pin is connected to the 1 pin of the transformer T1. The capacitors C3 and C4 are filter capacitors of the OUT pin of the voltage regulator IC1.

3. An independent drive board auxiliary power supply device as claimed in claim 2, characterized in that: The model of the voltage regulator IC1 is LM7824.

4. An independent drive board auxiliary power supply device as claimed in claim 2, characterized in that: The switching power supply circuit includes a power chip IC3, a capacitor C2, a capacitor C11, a resistor R1, a capacitor C5, a resistor R2, a resistor R4, a resistor R3, a diode D1, a resistor R7, a power switch tube Q1, a resistor R9, a capacitor C12, a resistor R8, a resistor R5, a capacitor C8, a diode D2, a resistor R6, a diode D3, a diode D4, a capacitor C9 and a capacitor C10. The resistor R1 is connected between pins 4 and 8 of the power chip IC3. The pins 4 and 8 of the power chip IC3 are also connected to the ground wire through capacitors C2 and C11 respectively. The pin 5 of the power chip IC3 is connected to the ground wire, and the pin 1 is connected to the capacitor C5 connected in parallel. The resistor R2 is connected to the 2nd pin of the power chip IC3, the 2nd pin of the power chip IC3 is connected to the OUT pin of the voltage regulator IC1 through the resistor R4 and the resistor R5 connected in series, the 2nd pin of the power chip IC3 is also connected to the ground wire through the resistor R3, the 6th pin of the power chip IC3 is connected to the G pole of the power switch tube Q1 through the resistor R7, the S pole of the power switch tube Q1 is connected to the ground wire through the resistor R9, and the D pole is connected to the 2nd pin of the transformer T1, the D pole of the power switch tube Q1 is also connected to the OUT pin of the voltage regulator IC1 through the resistor R6, the cathode of the diode D2 is connected to the OUT pin of the voltage regulator IC1 through the capacitor C8, and the anode is connected to the D pole of the power switch tube Q1; Pin 3 of the power chip IC3 is connected to the S pole of the power switch tube Q1 through the resistor R8, and pin 3 HIA of the power chip IC3 is connected to the ground wire through the capacitor C12; Pin 3 of transformer T1 is connected to the ground wire, pin 4 is connected to the positive electrode of diode D3, the negative electrode of diode D3 is connected to the positive electrode of diode D4, the negative electrode of diode D4 is connected to pin 2 of power chip IC3 through resistor R4, the negative electrode of diode D3 is connected to the ground wire through capacitor C9, and the negative electrode of diode D4 is connected to the ground wire through capacitor C10; Pins 6 and 5 of the transformer T1 output the first power supply, and pins 8 and 7 output the second power supply.

5. An independent drive board auxiliary power supply device as claimed in claim 4, characterized in that: The model of the power chip IC3 is UC3844, and the power switch tube Q1 is a MOSFET tube.

6. An independent drive board auxiliary power supply device as claimed in claim 4, characterized in that: The auxiliary power supply includes a voltage regulator IC2, a capacitor C6 and a capacitor C7. The IN pin of the voltage regulator IC2 is connected to the OUT pin of the voltage regulator IC1, and the OUT pin is connected to the 7th pin of the power chip IC3. The capacitors C6 and C7 are filter capacitors of the OUT pin of the voltage regulator IC2.

7. An independent drive board auxiliary power supply device as claimed in claim 6, characterized in that: The model of the voltage regulator IC2 is LM7816.

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