CN220492634U - Input protection control circuit and power converter - Google Patents
Input protection control circuit and power converter Download PDFInfo
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- CN220492634U CN220492634U CN202320687746.9U CN202320687746U CN220492634U CN 220492634 U CN220492634 U CN 220492634U CN 202320687746 U CN202320687746 U CN 202320687746U CN 220492634 U CN220492634 U CN 220492634U
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- 238000001514 detection method Methods 0.000 claims abstract description 70
- 230000003287 optical effect Effects 0.000 claims abstract description 32
- 230000000087 stabilizing effect Effects 0.000 claims description 14
- 239000003990 capacitor Substances 0.000 claims description 11
- 238000010586 diagram Methods 0.000 description 3
- 230000001052 transient effect Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
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Abstract
The utility model discloses an input protection control circuit, which is applied to a power converter, and comprises: the device comprises a power failure detection unit, an undervoltage detection unit, a high-voltage detection unit, an OR gate circuit, an optical coupler and a switch unit; the input end of the power-down detection unit is connected with external alternating voltage, and the output end of the power-down detection unit is connected with the first input end of the OR gate circuit; the input end of the undervoltage detection unit is used for being connected with alternating voltage, and the output end of the undervoltage detection unit is connected with the second input end of the OR gate circuit; the input end of the high-voltage detection unit is used for being connected with alternating voltage, and the output end of the high-voltage detection unit is connected with the third input end of the OR gate circuit; the input end of the optical coupler is connected with the output end of the OR gate circuit, and the output end of the optical coupler is connected with the input end of the switch unit. The circuit has a simple structure, reduces the number of optical couplers in a conventional control circuit, and reduces the design cost of products and the layout difficulty of a PCB.
Description
Technical Field
The present utility model relates to the field of switching power supplies, and in particular, to an input protection control circuit applied to a power converter.
Background
As the application of the power industry is more and more complex, especially in some occasions where the AC power grid is unstable, the AC power grid is easy to have transient power failure, too high or too low input voltage, so that the power output is power failure or failure occurs, and when the application equipment at the rear end of the switching power supply has sudden power failure at the power output end, the data of the application equipment may be lost or even damaged. In order to reduce the occurrence of data damage and potential safety hazards, three working conditions of transient power failure and excessively high or excessively low input voltage are monitored simultaneously, and the monitoring result is notified to the application equipment at the back end. The conventional processing mode is to transmit the voltage signals after the three working condition fault processing to the back-end user equipment respectively, and three optocouplers are needed to be used in the circuit structure, so that the circuit is complex, the cost is increased, and great challenges are brought to the layout of the primary side and the secondary side of the PCB.
Disclosure of Invention
In view of the problems existing in the prior art, the utility model provides an input protection control circuit and a power converter, which are used for simplifying the layout of a PCB, and simultaneously carrying out power failure detection, high voltage detection and undervoltage detection on the input end of the power converter, so that the circuit structure is simplified, and the design cost is reduced.
The technical scheme adopted by the utility model is as follows:
in a first aspect, an input protection control circuit is provided, applied to a power converter, the input protection control circuit comprising: the device comprises a power failure detection unit, an undervoltage detection unit, a high-voltage detection unit, an OR gate circuit, an optical coupler and a switch unit;
the input end of the power-down detection unit is connected with external alternating voltage, and the output end of the power-down detection unit is connected with the first input end of the OR gate circuit;
the input end of the undervoltage detection unit is used for being connected with alternating voltage, and the output end of the undervoltage detection unit is connected with the second input end of the OR gate circuit;
the input end of the high-voltage detection unit is used for being connected with alternating voltage, and the output end of the high-voltage detection unit is connected with the third input end of the OR gate circuit;
the input end of the optical coupler is connected with the output end of the OR gate circuit, and the output end of the optical coupler is connected with the input end of the switch unit.
Further, the power converter includes a transformer, and the power failure detection unit includes: the switching circuit comprises a rectifying circuit, a voltage stabilizing tube, a capacitor, a resistor R1, a resistor R2, a resistor R3 and a switching tube Q1;
the input end of the rectifying circuit is used as the input end of the power failure detection unit and is connected with the alternating voltage, and the output end of the rectifying circuit is connected with the cathode of the voltage stabilizing tube through a resistor R1; the cathode of the voltage stabilizing tube is respectively connected with the first end of the capacitor, the first end of the resistor R2 and the control end of the switching tube Q1, and the anode of the voltage stabilizing tube, the second end of the capacitor, the second end of the resistor R2 and the second end of the switching tube Q1 are grounded; the first end of the switching tube Q1 is connected with a primary side power supply signal of the transformer through a resistor R3, and a connection point of the first end of the switching tube Q1 and the resistor R3 is used as an output end of the power failure detection unit.
Further, the rectifying circuit includes a diode D1 and a diode D2; the anode of the diode D1 and the anode of the diode D2 are connected with alternating voltage; the cathode of the diode D1 is connected to the cathode of the diode D2, and the connection point thereof is used as the output terminal of the rectifying circuit.
Further, the or gate circuit includes: OR gate logic unit and switch tube Q2; the OR gate logic unit includes: diode D3, diode D4, and diode D5;
the anode of the diode D5 is used as a first input end of the OR gate circuit and is connected with the output end of the power failure detection unit; the anode of the diode D4 is a second input end of the OR gate circuit and is connected with the output end of the undervoltage detection unit; the anode of the diode D3 is a third input end of the OR gate and is connected with the output end of the high-voltage detection unit; the connection point of the cathode of the diode D3, the cathode of the diode D4 and the cathode of the diode D5 is connected with the control end of the switching tube Q2; the first end of the switch tube Q2 is the output end of the OR gate circuit, and the second end of the switch tube Q2 is grounded.
Further, the OR gate circuit also comprises a resistor R4 and a resistor R5; the resistor R4 is connected between the cathode of the diode D4 and the control end of the switching tube Q2; the resistor R5 is connected between the control terminal and the second terminal of the switching tube Q2.
Further, the input protection control circuit further comprises a resistor R6, a resistor R7 and a resistor R8;
the first end of the transmitting side of the optical coupler is used as the input end of the optical coupler to be connected with the output end of the OR gate circuit, and the second end of the transmitting side of the optical coupler is connected with the primary side power supply signal of the transformer through a resistor R6; the first end of the receiving side of the optical coupler is connected with the first end of the resistor R8, and the connection point of the first end is used as the output end of the optical coupler; the second end of the receiving side of the optical coupler is connected with a secondary side power supply signal of the transformer through a resistor R7; the second terminal of resistor R8 is grounded.
Further, the switching unit includes a switching tube Q3 and a diode D6; the control end of the switching tube Q3 is used as the input end of the switching unit and is connected with the output end of the optical coupler, the first end of the switching tube Q3 is connected with the cathode of the diode D6, and the second end of the switching tube Q3 is grounded; the anode of the diode D6 is connected with a secondary side power supply signal of the transformer.
Further, the switch unit further includes a resistor R9; resistor R9 is connected between the anode of diode D6 and the secondary power supply signal of the transformer.
In a second aspect, a power converter is provided, including a transformer, and further including an input protection control circuit according to any of the first aspects.
The utility model has the beneficial effects that: according to the utility model, the first input end of the OR circuit is connected with the output end of the power failure detection unit, the second input end of the OR circuit is connected with the output end of the undervoltage detection unit, and the third input end of the OR circuit is connected with the output end of the high-voltage detection unit, so that the input protection control circuit can simultaneously perform power failure detection, high-voltage detection and undervoltage detection on the input end of the power converter, the number of optocouplers in the conventional input protection control circuit is reduced, the circuit structure is simplified, and the design cost of products and the layout difficulty of a PCB (printed circuit board) are reduced.
Drawings
Fig. 1 is a schematic circuit diagram of an input protection control circuit according to the present utility model.
Detailed Description
The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.
Any feature disclosed in this specification (including any accompanying abstract and drawings), unless otherwise indicated, may be replaced by alternative features serving the same, equivalent or similar purpose. That is, each feature is one example only of a generic series of equivalent or similar features, unless expressly stated otherwise.
Fig. 1 is a schematic circuit diagram of an embodiment of the present utility model. The utility model provides an input protection control circuit, which is applied to a power converter, and comprises: a power-down detection unit, an undervoltage detection unit (not shown), a high voltage detection unit (not shown), an or circuit, an optocoupler OC1, and a switching unit;
the input end of the power-down detection unit is used for being connected with external alternating voltage, the output end of the power-down detection unit is connected with the first input end of the OR gate circuit, and the input voltage detection signal AC_OFF detected by the power-down detection unit is transmitted to the first input end of the OR gate circuit; the input end of the undervoltage detection unit is used for being connected with alternating voltage, the output end of the undervoltage detection unit is connected with the second input end of the OR gate circuit, and the undervoltage detection unit is used for transmitting an undervoltage signal VIN_UVP of the output end of the undervoltage detection unit to the second input end of the OR gate circuit; the input end of the high-voltage detection unit is used for being connected with alternating voltage, the output end of the high-voltage detection unit is connected with the third input end of the OR gate circuit, and the high-voltage detection unit is used for transmitting an overvoltage signal VIN_OVP of the output end of the high-voltage detection unit to the third input end of the OR gate circuit; the input end of the optical coupler OC1 is connected with the output end of the OR gate circuit, and the output end of the optical coupler OC1 is connected with the input end of the switch unit.
As a specific embodiment of the input protection control circuit, the power failure detection unit includes: the device comprises a rectifying circuit, a voltage stabilizing tube ZD1, a capacitor C1, a resistor R2, a resistor R3 and a MOS tube Q1; the rectifying circuit comprises a diode D1 and a diode D2; the OR gate circuit includes: the OR gate logic unit, the resistor R4, the resistor R5 and the switch tube Q2; the OR gate logic unit includes: diode D3, diode D4, and diode D5; the input protection control circuit also comprises a resistor R6, a resistor R7 and a resistor R8; the switch unit comprises a MOS tube Q3, a resistor R9 and a diode D6;
the anode of the diode D1 is connected with the L line of the alternating voltage, and the anode of the diode D2 is connected with the N line of the alternating voltage; the cathode of the diode D1 is connected with the cathode of the diode D2, and the connection point of the diode D1 is connected with the cathode of the voltage stabilizing tube ZD1 through a resistor R1; the cathode of the voltage stabilizing tube ZD1 is respectively connected with the first end of the capacitor C1, the first end of the resistor R2 and the grid electrode of the MOS tube Q1, and the anode of the voltage stabilizing tube ZD1, the second end of the capacitor C1, the second end of the resistor R2 and the source electrode of the MOS tube Q1 are grounded; the drain electrode of the MOS tube Q1 is connected with a primary side power supply signal PVCC of the transformer through a resistor R3; the connection point of the drain electrode of the MOS tube Q1 and the resistor R3 is connected with the anode of the diode D5; the anode of the diode D4 is connected with the output end of the undervoltage detection unit; the anode of the diode D3 is connected with the output end of the high-voltage detection unit; the connection point of the cathode of the diode D3, the cathode of the diode D4 and the cathode of the diode D5 is connected with the grid electrode of the MOS tube Q2 through a resistor R4; the source electrode of the MOS tube Q2 is grounded, and the resistor R5 is connected between the grid electrode and the source electrode of the MOS tube Q2; the drain electrode of the MOS tube Q2 is connected with the first end of the transmitting side of the optical coupler OC1, and the second end of the transmitting side of the optical coupler OC1 is connected with the primary side power supply signal PVCC of the transformer through a resistor R6; the first end of the receiving side of the optical coupler OC1 is grounded through a resistor R8, and the second end of the receiving side of the optical coupler OC1 is connected with a secondary side power supply signal SVCC of the transformer through a resistor R7; the grid of the MOS tube Q3 is connected with the first end of the receiving side of the optical coupler OC1, the source electrode of the MOS tube Q3 is grounded, the drain electrode of the MOS tube Q3 is connected with the cathode of the diode D6, and the anode of the diode D6 is connected with the secondary side power supply signal SVCC of the transformer through a resistor R9.
The or gate logic unit formed by the diode D3, the diode D4 and the diode D5 receives the input voltage detection signal ac_off, the undervoltage signal vin_uvp and the overvoltage signal vin_ovp respectively, the level signal output by the or gate logic unit is transmitted to the gate of the MOS transistor Q2 through the resistor R4, the gate level signal of the MOS transistor Q2 is recorded as ac_fail, and the logic control diagram of the or gate logic unit is shown in table 1.
| Number of combinations | AC_OFF | VIN_OVP | VIN_UVP | AC_Fail |
| 1 | 0 | 0 | 0 | 0 |
| 2 | 0 | 0 | 1 | 1 |
| 3 | 0 | 1 | 0 | 1 |
| 4 | 0 | 1 | 1 | 1 |
| 5 | 1 | 0 | 0 | 1 |
| 6 | 1 | 0 | 1 | 1 |
| 7 | 1 | 1 | 0 | 1 |
| 8 | 1 | 1 | 1 | 1 |
TABLE 1
The working principle of this embodiment is as follows:
under the condition that the input voltage is normal, the voltage value of the alternating current voltage at the input end of the power converter is stabilized at the threshold value of the voltage stabilizing tube ZD1 after the alternating current voltage at the input end of the power converter is subjected to the action of the rectifying circuit and the voltage stabilizing tube ZD1, the capacitor C1 is continuously charged, the MOS tube Q1 is conducted, at the moment, the input voltage detection signal AC_OFF is low level, the MOS tube Q2 is turned OFF, and the power converter works normally;
in the event of a transient power loss of the input voltage, the voltage of the capacitor C1 is discharged through the resistor R2,so thatThe MOS transistor Q1 is turned OFF, at this time, the input voltage detection signal AC_OFF is high level, after being processed by the OR gate logic unit, the gate voltage AC_Fail of the MOS transistor Q2 is high level, the MOS transistor Q2 is turned on, the optocoupler OC1 is turned on, so that the MOS transistor Q3 is turned on, and the voltage signal AC_OK at the output end of the power converter is changed from high level to low level. After detecting the change of the voltage signal ac_ok at the output end of the power converter, the user equipment saves data in advance, and disconnects the power converter.
Similarly, under the condition that the input voltage is normal, the input voltage detection signal AC_OFF, the overvoltage signal VIN_OVP and the undervoltage signal VIN_UVP are low-level signals, the MOS tube Q2 is turned OFF, and the power converter works normally;
when the input voltage exceeds or is lower than the normal input voltage working range, the overvoltage signal VIN_OVP or the undervoltage signal VIN_UVP is a high level signal, after being processed by the OR gate logic unit, the grid voltage AC_Fail of the MOS tube Q2 is high level, the MOS tube Q2 is conducted, the optical coupler OC1 is conducted, the MOS tube Q3 is conducted, and the voltage signal AC_OK of the output end of the power converter is changed from high level to low level. After detecting the change of the voltage signal ac_ok at the output end of the power converter, the user equipment saves data in advance, and disconnects the power converter.
It should be noted that the above is only a preferred embodiment of the present utility model, and it should be noted that the above preferred embodiment should not be construed as limiting the present utility model, and it should be recognized that the present utility model is applicable to other broader scope. In light of the foregoing, it will be evident to those skilled in the art that various modifications, substitutions and alterations can be made hereto without departing from the essential spirit of the utility model as defined by the appended claims.
Claims (9)
1. An input protection control circuit for use in a power converter, the input protection control circuit comprising: the device comprises a power failure detection unit, an undervoltage detection unit, a high-voltage detection unit, an OR gate circuit, an optical coupler and a switch unit;
the input end of the power-down detection unit is connected with external alternating voltage, and the output end of the power-down detection unit is connected with the first input end of the OR gate circuit;
the input end of the undervoltage detection unit is used for being connected with the alternating voltage, and the output end of the undervoltage detection unit is connected with the second input end of the OR gate circuit;
the input end of the high-voltage detection unit is used for being connected with the alternating voltage, and the output end of the high-voltage detection unit is connected with the third input end of the OR gate circuit;
the input end of the optical coupler is connected with the output end of the OR gate circuit, and the output end of the optical coupler is connected with the input end of the switch unit.
2. The input protection control circuit of claim 1, wherein the power converter comprises a transformer, and the power down detection unit comprises: the switching circuit comprises a rectifying circuit, a voltage stabilizing tube, a capacitor, a resistor R1, a resistor R2, a resistor R3 and a switching tube Q1;
the input end of the rectifying circuit is used as the input end of the power failure detection unit and is connected with the alternating voltage, and the output end of the rectifying circuit is connected with the cathode of the voltage stabilizing tube through a resistor R1; the cathode of the voltage stabilizing tube is respectively connected with the first end of the capacitor, the first end of the resistor R2 and the control end of the switching tube Q1, and the anode of the voltage stabilizing tube, the second end of the capacitor, the second end of the resistor R2 and the second end of the switching tube Q1 are grounded; the first end of the switching tube Q1 is connected with the primary side power supply signal of the transformer through the resistor R3, and the connection point of the first end of the switching tube Q1 and the resistor R3 is used as the output end of the power failure detection unit.
3. The input protection control circuit according to claim 2, wherein the rectifying circuit includes a diode D1 and a diode D2; the anode of the diode D1 and the anode of the diode D2 are connected with the alternating voltage; the cathode of the diode D1 is connected with the cathode of the diode D2, and the connection point of the cathode of the diode D1 is used as the output end of the rectifying circuit.
4. The input protection control circuit of claim 3, wherein the or gate circuit comprises: OR gate logic unit and switch tube Q2; the OR gate logic unit includes: diode D3, diode D4, and diode D5;
the anode of the diode D5 is used as a first input end of the OR gate circuit and is connected with the output end of the power failure detection unit; the anode of the diode D4 is connected with the output end of the undervoltage detection unit as the second input end of the OR gate circuit; the anode of the diode D3 is a third input end of the OR gate and is connected with the output end of the high-voltage detection unit; the connection points of the cathode of the diode D3, the cathode of the diode D4 and the cathode of the diode D5 are connected with the control end of the switching tube Q2; the first end of the switch tube Q2 is the output end of the OR gate circuit, and the second end of the switch tube Q2 is grounded.
5. The input protection control circuit of claim 4, wherein the or circuit further comprises a resistor R4 and a resistor R5; the resistor R4 is connected between the cathode of the diode D4 and the control end of the switching tube Q2; the resistor R5 is connected between the control end and the second end of the switching tube Q2.
6. The input protection control circuit of claim 5, further comprising a resistor R6, a resistor R7, and a resistor R8;
the first end of the transmitting side of the optical coupler is used as the input end of the optical coupler to be connected with the output end of the OR gate circuit, and the second end of the transmitting side of the optical coupler is connected with the primary side power supply signal of the transformer through the resistor R6; the first end of the receiving side of the optical coupler is connected with the first end of the resistor R8, and the connection point of the first end is used as the output end of the optical coupler; the second end of the receiving side of the optical coupler is connected with a secondary side power supply signal of the transformer through the resistor R7; the second end of the resistor R8 is grounded.
7. The input protection control circuit according to claim 6, wherein the switching unit includes a switching tube Q3 and a diode D6; the control end of the switching tube Q3 is used as the input end of the switching unit to be connected with the output end of the optical coupler, the first end of the switching tube Q3 is connected with the cathode of the diode D6, and the second end of the switching tube Q3 is grounded; the anode of the diode D6 is connected with a secondary side power supply signal of the transformer.
8. The input protection control circuit of claim 7, wherein the switching unit further comprises a resistor R9; the resistor R9 is connected between the anode of the diode D6 and the secondary side power supply signal of the transformer.
9. A power converter comprising a transformer, characterized by comprising an input protection control circuit as claimed in any one of the preceding claims 1-8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320687746.9U CN220492634U (en) | 2023-03-30 | 2023-03-30 | Input protection control circuit and power converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320687746.9U CN220492634U (en) | 2023-03-30 | 2023-03-30 | Input protection control circuit and power converter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220492634U true CN220492634U (en) | 2024-02-13 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320687746.9U Active CN220492634U (en) | 2023-03-30 | 2023-03-30 | Input protection control circuit and power converter |
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| Country | Link |
|---|---|
| CN (1) | CN220492634U (en) |
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- 2023-03-30 CN CN202320687746.9U patent/CN220492634U/en active Active
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