Switching power supply power-off output turn-off circuit
By designing a switching power supply power outage output shutdown circuit, the input unit, isolation unit and electronic switching unit are used to realize the synchronous shutdown of the switching power supply circuit when the power is powered off, the timing disorder caused by slow discharge of the output filter electrolytic capacitor is solved, and the power consumption is reduced and the power efficiency is ensured.
Patent Information
- Application Number
- CN202421511111.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-28
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2034-06-28
AI Technical Summary
When the switching power supply is powered off, the output filter electrolytic capacitor is discharged slowly, resulting in disordered power-up and power-off timing of the motherboard functional module, and the traditional solution has a large load loss, which affects the power efficiency.
A switching power supply power outage output shutdown circuit is designed, including an input unit, an isolation unit and an electronic switching unit. Through components such as optocoupler and MOS tube, the power supply of the electronic equipment motherboard is synchronously shut down when the switching power supply circuit is powered off.
When the switching power supply circuit is powered off, the power supply of the electronic equipment motherboard can be synchronously turned off to ensure that the motherboard timing is normal and the power consumption is low, and it does not affect the efficiency of the switching power supply circuit.
Smart Images
Figure CN222953925U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of electronic circuits, in particular to a switch power supply power-off output shutoff circuit. Background Art
[0002] Nowadays, electronic devices are becoming more and more functional. There are more and more functional modules on the motherboard of electronic devices, and the power supply types of each functional module are also increasing. Therefore, the power-on and power-off timing of each functional module of the motherboard is very important, especially in some operations, such as rapid shutdown and startup, etc. If the timing is improper, it will cause a freeze. In addition, when the power grid fluctuates and the voltage drops temporarily, the electronic equipment cannot work normally or cannot automatically restart and recover.
[0003] At present, switching power supplies are generally used to power the motherboard of electronic equipment. The capacity of the output filter electrolytic capacitor of the switching power supply is very large (several thousand uF). Therefore, the output filter electrolytic capacitor of the switching power supply discharges slowly when the switching power supply is powered off, which is more likely to cause the power-on and power-off timing of various functional modules of the motherboard to be disordered. The traditional solution is to connect a load in parallel to the output end of the switching power supply to quickly consume the power of the output filter electrolytic capacitor of the switching power supply through the load. However, the load loss is large, which will affect the efficiency of the switching power supply, and the discharge speed of the output filter electrolytic capacitor of the switching power supply is greatly affected by the resistance value of the load and its own capacity.
[0004] To solve the above problems, a power-off output shutdown circuit is designed to control the standby voltage shutdown, so that the motherboard can stop working when power is off and work normally after power is on, ensuring the normal timing of the motherboard and the efficiency of the power board.
[0005] In view of the above problems, it is necessary to study a switching power supply power-off output shutdown circuit, which can synchronously shut down the power supply of the electronic device motherboard when the switching power supply circuit is powered off, and has low power consumption. Utility Model Content
[0006] The utility model aims to provide a switching power supply power-off output shut-off circuit, which can synchronously shut off the power supply of the electronic device mainboard when the switching power supply circuit is powered off, and has low power consumption.
[0007] In order to achieve the above purpose, the solution of the utility model is:
[0008] A switching power supply power-off output shutdown circuit is used to cooperate with the switching power supply circuit and the electronic equipment mainboard, and comprises an input unit, an isolation unit, and an electronic switch unit; the input side of the input unit is connected to the auxiliary winding of the transformer T1 of the switching power supply circuit, the output side of the input unit is connected to the input side of the isolation unit, the output side of the isolation unit is connected to the control end of the electronic switch unit, the input end of the electronic switch unit is connected to the output end of the switching power supply, and the output end of the electronic switch unit is connected to the power supply end of the electronic equipment mainboard.
[0009] The input unit includes a diode D1, a resistor R1, a resistor R2 and a capacitor C1; the positive electrode of the diode D1 is connected to the positive electrode of the input side of the input unit, the negative electrode of the diode D1 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the resistor R2 and the first end of the capacitor C1, the second end of the resistor R2 is connected to the positive electrode of the output side of the input unit, the second end of the capacitor C1 is connected to the first ground terminal, and the second end of the capacitor C1 is connected to the negative electrode of the input side of the input unit and the negative electrode of the output side of the input unit; the positive electrode and the negative electrode of the input side of the input unit are respectively connected to the two ends of the auxiliary winding of the transformer T1 of the switching power supply circuit; the positive electrode and the negative electrode of the output side of the input unit are respectively connected to the positive electrode and the negative electrode of the input side of the isolation unit.
[0010] The electronic switch unit includes a MOS tube Q1, a resistor R3 and a resistor R4; the source of the MOS tube Q1 and the first end of the resistor R4 are connected to the input end of the electronic switch unit, the drain of the MOS tube Q1 is connected to the output end of the electronic switch unit, the gate of the MOS tube Q1 is connected to the second end of the resistor R4 and the first end of the resistor R3, the first end of the resistor R3 is connected to the control end of the electronic switch unit, the control end of the electronic switch unit is connected to the positive electrode of the output side of the isolation unit, and the negative electrode of the output side of the isolation unit is connected to the second ground end.
[0011] The isolation unit uses an optical coupler U1.
[0012] After adopting the above scheme, the working principle of the utility model is as follows: when the switching power supply circuit works normally, the auxiliary winding of the transformer T1 of the switching power supply circuit is energized and supplies power to the input side of the isolation unit through the input unit, and then the output side of the isolation unit is turned on to control the electronic switch unit to be turned on, so that the output end of the switching power supply circuit supplies power to the electronic device mainboard through the electronic switch unit; when the switching power supply circuit is powered off (that is, when there is no power input to the input end of the switching power supply circuit), the auxiliary winding of the transformer T1 of the switching power supply circuit has no voltage and the input side of the isolation unit is powered off, and then the output side of the isolation unit is disconnected and the electronic switch unit is controlled to be disconnected, so that the output end of the switching power supply circuit cannot supply power to the electronic device mainboard through the electronic switch unit, so that the electronic device mainboard is powered off synchronously.
[0013] From the above, it can be seen that the utility model can make the electronic device mainboard synchronously power off when the switching power supply circuit is powered off, thereby ensuring the normal timing of the electronic device mainboard; and a switching power supply power-off output shutdown circuit of the utility model has low power consumption and will not affect the efficiency of the switching power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is the principle diagram of the utility model. DETAILED DESCRIPTION
[0015] In order to further explain the technical solution of the present utility model, the present utility model is described in detail below through specific embodiments.
[0016] like Figure 1 As shown, the utility model discloses a switching power supply power-off output shutdown circuit, which is used to cooperate with the switching power supply circuit and the electronic equipment mainboard; the switching power supply power-off output shutdown circuit of the utility model includes an input unit, an isolation unit, and an electronic switch unit; wherein, the input side of the input unit is connected to the auxiliary winding of the transformer T1 of the switching power supply circuit, the output side of the input unit is connected to the input side of the isolation unit, the output side of the isolation unit is connected to the control end of the electronic switch unit, the input end of the electronic switch unit is connected to the output end of the switching power supply, and the output end of the electronic switch unit is connected to the power supply end of the electronic equipment mainboard.
[0017] The working principle of the utility model is as follows: when the switching power supply circuit works normally, the auxiliary winding of the transformer T1 of the switching power supply circuit is energized and supplies power to the input side of the isolation unit through the input unit, and then the output side of the isolation unit is turned on to control the electronic switch unit to be turned on, so that the output end of the switching power supply circuit supplies power to the electronic device mainboard through the electronic switch unit; when the switching power supply circuit is powered off (that is, when there is no power input at the input end of the switching power supply circuit), the auxiliary winding of the transformer T1 of the switching power supply circuit has no voltage and the input side of the isolation unit is powered off, and then the output side of the isolation unit is disconnected and the electronic switch unit is controlled to be disconnected, so that the output end of the switching power supply circuit cannot supply power to the electronic device mainboard through the electronic switch unit, so that the electronic device mainboard is powered off synchronously. As can be seen from the foregoing, the utility model can make the electronic device mainboard be powered off synchronously when the switching power supply circuit is powered off, ensuring that the timing of the electronic device mainboard is normal; and a switching power supply power-off output shutdown circuit of the utility model has low power consumption and will not affect the efficiency of the switching power supply circuit.
[0018] Cooperate Figure 1As shown, in an embodiment of the utility model, the input unit includes a diode D1, a resistor R1, a resistor R2 and a capacitor C1; the positive electrode of the diode D1 is connected to the positive electrode of the input side of the input unit, the negative electrode of the diode D1 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the resistor R2 and the first end of the capacitor C1, the second end of the resistor R2 is connected to the positive electrode of the output side of the input unit, the second end of the capacitor C1 is connected to the first ground terminal, and the second end of the capacitor C1 is connected to the negative electrode of the input side of the input unit and the negative electrode of the output side of the input unit; the positive electrode and the negative electrode of the input side of the input unit are respectively connected to the two ends of the auxiliary winding of the transformer T1 of the switching power supply circuit; the positive electrode and the negative electrode of the output side of the input unit are respectively connected to the positive electrode and the negative electrode of the input side of the isolation unit. When the auxiliary winding of the transformer T1 of the switching power supply circuit is energized, the voltage of the auxiliary winding of the transformer T1 of the switching power supply circuit can be input to the input side of the isolation unit through the diode D1, the resistor R1 and the resistor R2 to supply power to the input side of the isolation unit, wherein the diode D1 can play a role of preventing reverse voltage from being input to the input side of the isolation unit and causing damage to the isolation unit, and the resistor R1, the resistor R2 and the capacitor C1 can play a role of current limiting and filtering to protect the isolation unit.
[0019] Cooperate Figure 1 As shown, in an embodiment of the present utility model, the isolation unit adopts an optical coupler U1.
[0020] Cooperate Figure 1 As shown, in an embodiment of the utility model, the electronic switch unit includes a MOS tube Q1, a resistor R3 and a resistor R4; the source of the MOS tube Q1 and the first end of the resistor R4 are connected to the input end of the electronic switch unit, the drain of the MOS tube Q1 is connected to the output end of the electronic switch unit, the gate of the MOS tube Q1 is connected to the second end of the resistor R4 and the first end of the resistor R3, the first end of the resistor R3 is connected to the control end of the electronic switch unit, the control end of the electronic switch unit is connected to the positive electrode of the output side of the isolation unit, and the negative electrode of the output side of the isolation unit is connected to the second ground end. When the output side of the isolation unit is turned on, the MOS tube Q1 is turned on; when the output side of the isolation unit is disconnected, the MOS tube Q1 is turned off.
[0021] The above embodiments and drawings do not limit the product form and style of the present utility model. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present utility model.
Claims
1. A switching power supply power-off output shutdown circuit, which is used to cooperate with a switching power supply circuit and an electronic device mainboard, characterized in that: It includes an input unit, an isolation unit, and an electronic switch unit; The input side of the input unit is connected to the auxiliary winding of the transformer T1 of the switching power supply circuit, the output side of the input unit is connected to the input side of the isolation unit, the output side of the isolation unit is connected to the control end of the electronic switch unit, the input end of the electronic switch unit is connected to the output end of the switching power supply, and the output end of the electronic switch unit is connected to the power supply end of the electronic device mainboard.
2. A switching power supply power-off output shutdown circuit as claimed in claim 1, characterized in that: The input unit includes a diode D1, a resistor R1, a resistor R2 and a capacitor C1; the anode of the diode D1 is connected to the anode of the input side of the input unit, the cathode of the diode D1 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first end of the resistor R2 and the first end of the capacitor C1, the second end of the resistor R2 is connected to the anode of the output side of the input unit, the second end of the capacitor C1 is connected to the first ground terminal, and the second end of the capacitor C1 is connected to the cathode of the input side of the input unit and the cathode of the output side of the input unit; The positive and negative electrodes of the input side of the input unit are respectively connected to the two ends of the auxiliary winding of the transformer T1 of the switching power supply circuit; the positive and negative electrodes of the output side of the input unit are respectively connected to the positive and negative electrodes of the input side of the isolation unit.
3. A switching power supply power-off output shutdown circuit as claimed in claim 1, characterized in that: The electronic switch unit includes a MOS tube Q1, a resistor R3 and a resistor R4; the source of the MOS tube Q1 and the first end of the resistor R4 are connected to the input end of the electronic switch unit, the drain of the MOS tube Q1 is connected to the output end of the electronic switch unit, the gate of the MOS tube Q1 is connected to the second end of the resistor R4 and the first end of the resistor R3, the first end of the resistor R3 is connected to the control end of the electronic switch unit, the control end of the electronic switch unit is connected to the positive electrode of the output side of the isolation unit, and the negative electrode of the output side of the isolation unit is connected to the second ground end.
4. A switching power supply power-off output shutdown circuit as claimed in claim 1, characterized in that: The isolation unit uses an optical coupler U1.