Power supply slow start circuit

Abstract

The utility model discloses a power supply slow start circuit which comprises a main circuit module, a first comparison circuit module, a second comparison circuit module and a discharge circuit module, and the first comparison circuit module, the second comparison circuit module and the discharge circuit module are connected with the main circuit module. The main circuit module comprises a power supply input + VIN, a slow start resistor R2, a normally open relay K1 and a normally closed relay K2, the first comparison circuit module comprises a resistor R1, a resistor R3, a resistor R4, a resistor R5 and a comparator U1, and the second comparison circuit module comprises a resistor R1, a resistor R3, a resistor R4, a resistor R5 and a comparator U1. And the discharge circuit module comprises a discharge resistor R10, a current limiting resistor R11, a diode D1, an energy storage capacitor C1 and a PMOS (P-channel Metal Oxide Semiconductor) tube Q1. The power supply circuit has the beneficial effects of effectively inhibiting impact current when equipment is powered on, reducing power supply input power consumption, being capable of repeatedly powering off and restarting the power supply circuit, and also being capable of ensuring normal work of the power supply circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of starting circuits, in particular to a power supply slow starting circuit. Background Art

[0002] In the current power electronics industry, switches are usually used to control the start and stop of power supplies. When the switch starts electrical equipment, there is an overvoltage or overcurrent phenomenon, which causes damage to components and reduces the service life of the entire equipment. In severe cases, the equipment may be burned. Some circuits use software slow-start solutions and are connected through MCU chip control. In this circuit, it is necessary to pull out the control power separately to power the MCU, and when the MCU freezes, the entire power supply system cannot work properly. In some slow-start circuits, slow-start circuits are designed through thermistors. According to the characteristics of thermistors, when the power is turned on at the beginning, the resistance value is large, and the circuit voltage can increase slowly. When the circuit is stable, the temperature of the thermistor rises, and the resistance value slowly decreases to complete the slow-start circuit. However, when the power circuit is restarted, the heat energy cannot drop quickly, the resistance value is too small, and the impact current is too large, so the slow start cannot be completed. Most of the existing slow-start circuits cannot realize the repeated start function, and some slow-start circuits choose to directly connect a slow-start resistor in parallel to the main circuit to form a slow-start circuit. However, this design will increase another branch, thereby increasing the power consumption of the power input.

[0003] In view of the above problems, the inventor proposes a power supply slow start circuit to solve the above problems. Utility Model Content

[0004] In order to achieve the above purpose, the utility model adopts the following technical means:

[0005] A power supply slow start circuit comprises a main circuit module, a first comparison circuit module, a second comparison circuit module and a discharge circuit module, wherein the first comparison circuit module, the second comparison circuit module and the discharge circuit module are respectively connected to the main circuit module;

[0006] The main circuit module includes: power input +VIN, slow-start resistor R2, normally open relay K1, normally closed relay K2;

[0007] The first comparison circuit module includes: a resistor R1, a resistor R3, a resistor R4, a resistor R5, and a comparator U1;

[0008] The second comparison circuit module includes: a resistor R6, a resistor R7, a resistor R8, a resistor R9, and a comparator U2;

[0009] The discharge circuit module includes: a discharge resistor R10, a current limiting resistor R11, a diode D1, an energy storage capacitor C1, and a PMOS tube Q1.

[0010] A further solution of the utility model is that one end of the slow-start resistor R2 is connected to the power input +VIN, the other end of the slow-start resistor R2 is connected to pin 1 of the normally closed relay K2, pins 1 and 2 of the normally open relay K1 are respectively connected to the power input +VIN, and pin 4 of the normally open relay K1, pin 2 of the normally closed relay K2, and pin 3 of the normally closed relay K2 are respectively connected to the output +Vout1.

[0011] A further solution of the utility model is that one end of the resistor R1 and the resistor R3 are respectively connected to pin 3 of the comparator U1, one end of the resistor R4 and the resistor R5 are respectively connected to pin 4 of the comparator U1, the other ends of the resistor R1 and the resistor R5 are respectively connected to GND, the other end of the resistor R3 is connected to the power input +VIN in the main circuit module, the other end of the resistor R4 is connected to the output +Vout1, and pin 1 of the comparator U1 is connected to pin 3 of the normally open relay K1 in the main circuit module.

[0012] A further solution of the utility model is that one end of the resistor R6 and the resistor R7 are respectively connected to pin 4 of the comparator U2, one end of the resistor R8 and the resistor R9 are respectively connected to pin 3 of the comparator U2, the other end of the resistor R6 is connected to the output +Vout1, the other ends of the resistor R7 and the resistor R9 are respectively connected to GND, the other end of the resistor R8 is connected to the power input +VIN in the main circuit module, and pin 1 of the comparator U2 is connected to pin 4 of the normally closed relay K2 in the main circuit module.

[0013] A further solution of the utility model is that one end of the resistor R10 is connected to the drain of the PMOS tube Q1, the other end of the resistor R10 is connected to GND, one end of the resistor R11 is connected to the anode of the diode D1, the other end of the resistor R11 is connected to the gate of the PMOS tube Q1, the anode of the diode D1 is connected to the output +Vout1, the cathode of the diode D1 is connected to the output +Vout2, one end of the capacitor C1 is connected to the cathode of the diode D1, the other end of the capacitor C1 is connected to GND, and the source of the PMOS tube Q1 is connected to the cathode of the diode D1.

[0014] Beneficial effects of the utility model:

[0015] The utility model increases the voltage slowly to the output terminal +Vout1 through the main circuit module. When the voltage is large enough, the first comparison circuit module controls the K1 relay to start to pull in. At this time, the voltage of +Vout1 is equal to the voltage of the power input +VIN. Then, the second comparison circuit module controls the relay K2 to start to pull in. K2 changes from the previous normally closed to normally open, disconnects this branch, and reduces the power circuit loss. When the input power is powered off, the discharge circuit module starts to work and discharges quickly through the resistor R10. The above technical solution can complete the slow start of the power circuit. For some circuits with large capacitive loads in the back stage, the impact current is large, and the slow start resistor R2 has a certain inhibitory effect. The normally closed relay K2 is used to control the opening and closing state of the branch, thereby reducing the power input power consumption. The discharge circuit module can complete the rapid discharge of the entire circuit to meet the repeated opening state of the device. Therefore, the above technical solution can effectively suppress the impact current when the device is powered on, reduce the power input power consumption, and the power circuit can be repeatedly powered off and restarted, which can also ensure the normal operation of the power circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a circuit schematic diagram of the utility model;

[0017] Reference numerals:

[0018] A main circuit module 10 , a first comparison circuit module 20 , a second comparison circuit module 30 , and a discharge circuit module 40 . DETAILED DESCRIPTION

[0019] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Example

[0023] As attached Figure 1 As shown, the utility model provides a power supply slow start circuit, including a main circuit module 10, a first comparison circuit module 20, a second comparison circuit module 30, and a discharge circuit module 40, wherein the first comparison circuit module 20, the second comparison circuit module 30, and the discharge circuit module 40 are respectively connected to the main circuit module 10;

[0024] Among them, one end of the main circuit module 10 is connected to the power input +VIN, and the other end is connected to the output end Vout1. The main circuit module 10 is controlled by the first comparison circuit module 20 and the second comparison circuit module 30 to disconnect the parallel branch and reduce the loss. The entire power circuit is quickly discharged through the discharge circuit module 40 to complete the slow start of the entire power circuit.

[0025] The main circuit module 10 includes: a power input +VIN, a slow-start resistor R2, a normally open relay K1, and a normally closed relay K2;

[0026] One end of the slow-start resistor R2 is connected to the power input +VIN, the other end of the slow-start resistor R2 is connected to pin 1 of the normally closed relay K2, pins 1 and 2 of the normally open relay K1 are connected to the power input +VIN respectively, and pin 4 of the normally open relay K1, pin 2 of the normally closed relay K2, and pin 3 of the normally closed relay K2 are connected to the output +Vout1 respectively;

[0027] The slow-start resistor R2 is used to suppress the impact current generated by the instantaneous start-up of the power supply voltage. The power input +VIN forms a path through the slow-start resistor R2 and the normally closed relay K2, so that the output +Vout1 voltage rises slowly.

[0028] The first comparison circuit module 20 includes: a resistor R1, a resistor R3, a resistor R4, a resistor R5, and a comparator U1;

[0029] One end of resistor R1 and resistor R3 is respectively connected to pin 3 of comparator U1, one end of resistor R4 and resistor R5 is respectively connected to pin 4 of comparator U1, the other ends of resistor R1 and resistor R5 are respectively connected to GND, the other end of resistor R3 is connected to the power input +VIN in the main circuit module, the other end of resistor R4 is connected to output +Vout1, and pin 1 of comparator U1 is connected to pin 3 of the normally open relay K1 in the main circuit module;

[0030] Among them, resistor R1 and resistor R3 form a complete circuit, where V1 is the ground voltage of its loop and is connected to the positive terminal of pin 3 in comparator U1; resistor R4 and resistor R5 form a complete loop, where V2 is the ground voltage in its loop and is connected to the negative terminal of pin 4 in the first comparator U1; +Vout1 can be designed as the voltage required by the power supply circuit. During this power-on process, it is always in a slow start state. When there is a small voltage difference between the +Vout1 voltage and the +VIN voltage, at this time, the normally open relay K1 is attracted, and the inrush current will not be too large. Among them,

[0031]

[0032] The magnitude of the +Vout1 voltage can be adjusted according to resistor R1, resistor R3, resistor R4, and resistor R5;

[0033] When V2 < V1, pin 1 of comparator U1 outputs a high level, and the coil voltage of the normally open relay K1 does not meet the attraction condition and cannot be attracted;

[0034] When V2 > V1, pin 1 of comparator U1 outputs a low level, and the coil voltage of the normally open relay K1 meets the attraction condition, and the relay is attracted. At this time, the +Vout1 voltage rises rapidly until +Vout1 = +VIN.

[0035] The second comparison circuit module 30 includes; resistor R6, resistor R7, resistor R8, resistor R9, comparator U2;

[0036] One end of resistor R6 and resistor R7 is respectively connected to pin 4 of comparator U2, one end of resistor R8 and resistor R9 is respectively connected to pin 3 of comparator U2, the other end of resistor R6 is connected to output +Vout1, the other ends of resistor R7 and resistor R9 are respectively connected to GND, the other end of resistor R8 is connected to the power input +VIN in the main circuit module, and pin 1 of comparator U2 is connected to pin 4 of the normally closed relay K2 in the main circuit module;

[0037] Among them, resistor R8 and resistor R9 form a complete power supply circuit, where V3 is the ground voltage in its loop and is connected to the non-inverting input terminal of pin 3 of comparator U2. Resistor R6 and resistor R7 form a complete circuit, where V4 is the ground voltage in its loop and is connected to the inverting input terminal of pin 4 of comparator U2. The switching state of the normally closed relay K2 can be controlled according to the voltages of V3 and V4. Among them,

[0038]

[0039] When V4 < V3, the output of pin 1 of comparator U2 is high level. The voltage of the coil of the normally closed relay K2 does not meet the energizing condition and cannot be energized;

[0040] When V4 > V3, the output of pin 1 of comparator U2 is low level. The voltage of the coil of the normally closed relay K2 meets the energizing condition and the relay is energized;

[0041] When the normally open relay K1 is energized, the input power supply forms a closed-loop circuit through the normally open relay K1, and also forms a closed-loop power with resistor R2 and the normally closed relay K2, which will increase the power consumption of the device. When the normally closed relay K2 is energized, the relay changes from the original normally closed state to the normally open state. At this time, the branch formed by resistor R2 and the normally closed relay K2 is disconnected, reducing the power consumption of the input power supply.

[0042] The discharge circuit module 40 includes: discharge resistor R10, current-limiting resistor R11, diode D1, energy storage capacitor C1, PMOS transistor Q1;

[0043] One end of resistor R10 is connected to the drain of PMOS transistor Q1, and the other end of resistor R10 is connected to GND. One end of resistor R11 is connected to the anode of diode D1, and the other end of resistor R11 is connected to the gate of PMOS transistor Q1. The anode of diode D1 is connected to output +Vout1, the cathode of diode D1 is connected to output +Vout2, one end of capacitor C1 is connected to the cathode of diode D1, the other end of capacitor C1 is connected to GND, and the source of PMOS transistor Q1 is connected to the cathode of diode D1;

[0044] Among them, when the power supply circuit loses power, the voltage of +Vout1 gradually decreases. The voltage of +Vout2 can still be maintained due to the capacitance of the energy storage capacitor C1. The gate G of PMOS transistor Q1 < S pole. When the voltage is less than the conduction voltage of PMOS transistor Q1, this PMOS transistor Q1 starts to conduct. The entire loop is that the voltage of +Vout2 forms a discharge loop through PMOS transistor Q1 and discharge resistor R10, and can quickly release the voltage of the subsequent stage to complete the discharge of the entire loop.

[0045] The examples given in the present invention are not limitations on the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived from them are still within the scope of protection of the present invention.

Claims

1. A power supply slow start circuit, characterized in that: It includes a main circuit module, a first comparison circuit module, a second comparison circuit module, and a discharge circuit module, wherein the first comparison circuit module, the second comparison circuit module, and the discharge circuit module are respectively connected to the main circuit module; The main circuit module includes: power input +VIN, slow-start resistor R2, normally open relay K1, normally closed relay K2; The first comparison circuit module includes: a resistor R1, a resistor R3, a resistor R4, a resistor R5, and a comparator U1; The second comparison circuit module includes: a resistor R6, a resistor R7, a resistor R8, a resistor R9, and a comparator U2; The discharge circuit module includes: a discharge resistor R10, a current limiting resistor R11, a diode D1, an energy storage capacitor C1, and a PMOS tube Q1.

2. A power supply slow start circuit according to claim 1, characterized in that: One end of the slow-start resistor R2 is connected to the power input +VIN, the other end of the slow-start resistor R2 is connected to pin 1 of the normally closed relay K2, pins 1 and 2 of the normally open relay K1 are respectively connected to the power input +VIN, and pin 4 of the normally open relay K1, pin 2 of the normally closed relay K2, and pin 3 of the normally closed relay K2 are respectively connected to the output +Vout1.

3. A power supply slow start circuit according to claim 2, characterized in that: One end of the resistor R1 and the resistor R3 are respectively connected to pin 3 of the comparator U1, one end of the resistor R4 and the resistor R5 are respectively connected to pin 4 of the comparator U1, the other ends of the resistor R1 and the resistor R5 are respectively connected to GND, the other end of the resistor R3 is connected to the power input +VIN in the main circuit module, the other end of the resistor R4 is connected to the output +Vout1, and pin 1 of the comparator U1 is connected to pin 3 of the normally open relay K1 in the main circuit module.

4. A power supply slow start circuit according to claim 2, characterized in that: One end of the resistor R6 and the resistor R7 are respectively connected to pin 4 of the comparator U2, one end of the resistor R8 and the resistor R9 are respectively connected to pin 3 of the comparator U2, the other end of the resistor R6 is connected to the output +Vout1, the other ends of the resistor R7 and the resistor R9 are respectively connected to GND, the other end of the resistor R8 is connected to the power input +VIN in the main circuit module, and pin 1 of the comparator U2 is connected to pin 4 of the normally closed relay K2 in the main circuit module.

5. A power supply slow start circuit according to claim 2, characterized in that: One end of the resistor R10 is connected to the drain of the PMOS tube Q1, and the other end of the resistor R10 is connected to GND. One end of the resistor R11 is connected to the anode of the diode D1, and the other end of the resistor R11 is connected to the gate of the PMOS tube Q1. The anode of the diode D1 is connected to the output +Vout1, and the cathode of the diode D1 is connected to the output +Vout2. One end of the capacitor C1 is connected to the cathode of the diode D1, and the other end of the capacitor C1 is connected to GND. The source of the PMOS tube Q1 is connected to the cathode of the diode D1.

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