CN216437054U - Input circuit of switching power supply - Google Patents
Input circuit of switching power supply Download PDFInfo
- Publication number
- CN216437054U CN216437054U CN202123154809.4U CN202123154809U CN216437054U CN 216437054 U CN216437054 U CN 216437054U CN 202123154809 U CN202123154809 U CN 202123154809U CN 216437054 U CN216437054 U CN 216437054U
- Authority
- CN
- China
- Prior art keywords
- resistor
- power supply
- current transformer
- switching power
- capacitor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model provides a switching power supply's input circuit, including power input end, current transformer, first resistance, second resistance, MOS pipe and rectification filter circuit. The power input end is connected with a rectifying and filtering circuit through a primary coil and an MOS tube on the current transformer in sequence, the first resistor is connected with the second resistor in series, and two ends of the series are respectively connected with two ends of a secondary coil on the current transformer. One end of a secondary coil on the current transformer is connected with the output end of the rectification filter circuit, and the grid of the MOS tube is respectively connected with the first resistor and the second resistor. The voltage generated by the secondary coil of the current transformer is divided by the first resistor and the second resistor to control the disconnection of the MOS tube, so that the output of the power supply can be disconnected, the damage of components of the switching power supply is prevented, and the effect of protecting the switching power supply is achieved.
Description
[ technical field ] A method for producing a semiconductor device
The utility model belongs to the technical field of switching power supply's technique and specifically relates to a switching power supply's input circuit is related to.
[ background of the invention ]
As is known, a switching power supply is configured to perform rectification and filtering processing on an input power supply and then output the rectified power supply from a transformer, wherein the output voltage is fed back to a power management chip through a feedback circuit, and the power management chip controls the on/off or the magnitude of the output power supply of the transformer by controlling a power switch, so as to achieve a constant voltage effect. However, at present, the power input in the existing switching power supply is easily affected by the surge current of the power grid, and the existing power input circuit does not have a surge protection circuit, so that when the power surge input on the power grid is large, the components of the switching power supply are easily damaged, and the use of the switching power supply is affected.
Accordingly, the prior art is in need of improvement and development.
[ Utility model ] A method for manufacturing a semiconductor device
An object of the utility model is to provide a switching power supply's input circuit for solve current switching power supply and influence the problem of use easily by the surge influence of net input.
The technical scheme of the utility model as follows: an input circuit of a switching power supply comprises a power supply input end, a current transformer, a first resistor, a second resistor, an MOS tube and a rectifying and filtering circuit,
the power input end is connected with a rectifying and filtering circuit through a primary coil and an MOS tube on the current transformer in sequence; the first resistor and the second resistor are connected in series, and two ends of the first resistor and the second resistor after the first resistor and the second resistor are connected in series are respectively connected with two ends of a secondary coil on the current transformer; one end of a secondary coil on the current transformer is connected with the output end of the rectification filter circuit, and the grid of the MOS tube is respectively connected with a first resistor and a second resistor;
and the voltage generated by a secondary coil of the current transformer is divided by the first resistor and the second resistor and then the on-off of the MOS tube is controlled.
Further, the power input end comprises a zero line and a live line; and the live wire is connected with a fuse and is connected with a primary coil of the current transformer through the fuse.
Further, the input circuit further comprises a first diode connected between the current transformer and the first resistor in series.
Furthermore, the input circuit further comprises a first capacitor, a magnetic excitation coil and a rectifier, one end of the first capacitor is connected with a primary coil of the current transformer and a third pin of the magnetic excitation coil, a fourth pin of the magnetic excitation coil and the other end of the first capacitor are both connected with a zero line, the first pin and the second pin of the magnetic excitation coil are connected with the input end of the rectifier, and the output end of the rectifier is connected with the MOS tube.
Furthermore, the rectification filter circuit comprises a second capacitor, a third capacitor and an inductor, the two ends of the inductor are respectively connected with the source electrode of the MOS tube and the transformer, the two ends of the first capacitor are respectively connected with the input end of the inductor and the ground, and the two ends of the second capacitor are respectively connected with the output end of the inductor and the ground.
Furthermore, the input circuit further comprises a piezoresistor, one end of the piezoresistor is connected with the primary coil of the current transformer and the third pin of the magnetic excitation coil, and the other end of the piezoresistor is connected with a zero line.
Further, the MOS tube is a P-channel MOS tube.
The beneficial effects of the utility model reside in that: compared with the prior art, the utility model discloses utilize current transformer and the partial pressure of cooperation first resistance and second resistance, when power input end's electric current was too big, the electric current of handling secondary coil input through current transformer can drive the disconnection of MOS pipe after first resistance partial pressure, and then the output of disconnected power supply prevents the damage of switching power supply components and parts, plays the effect of protection switching power supply.
[ description of the drawings ]
Fig. 1 is a schematic circuit diagram of the present invention.
[ detailed description ] embodiments
The present invention will be further described with reference to the accompanying drawings and embodiments.
Referring to fig. 1, an input circuit of a switching power supply according to an embodiment of the present invention is shown.
The input circuit of the switching power supply comprises a power supply input end 1, a current transformer LX, a first resistor R1, a second resistor R2, a MOS (metal oxide semiconductor) tube Q1 and a rectifying and filtering circuit 2. The power input end 1 is connected with the rectifying and filtering circuit 2 through a primary coil on the current transformer LX and an MOS (metal oxide semiconductor) tube Q1 in sequence, the first resistor R1 is connected with the second resistor R2 in series, and two ends of the series are respectively connected with two ends of a secondary coil on the current transformer LX. One end of a secondary coil on the current transformer LX is connected with the output end of the rectifying and filtering circuit 2, and the grid of the MOS transistor Q1 is respectively connected with the first resistor R1 and the second resistor R2.
The utility model discloses utilize current transformer LX to produce the electric current at secondary coil to cooperation first resistance R1 and second resistance R2's partial pressure, when power input end 1's electric current was too big, after first resistance R1, second resistance R2 partial pressure, drive MOS pipe Q1 disconnection through the electric current that current transformer LX last secondary coil produced, and then but the output of disconnect-able power supply plays the guard action. When the current is normal, the current input by the secondary coil processed by the current transformer LX is divided by the first resistor R1 and the second resistor R2 and is not enough to drive the MOS transistor Q1 to turn off, i.e., the MOS transistor Q1 is turned on, so that the switching power supply outputs the power normally. Therefore, when the power surge input to the power grid is large, the MOS transistor Q1 is disconnected, so that the damage of the components of the switching power supply can be prevented, the effect of protecting the switching power supply is achieved, and a certain protection effect can be achieved when the power output is abnormal.
Specifically, in this embodiment, the MOS transistor Q1 is a P-channel MOS transistor Q1, and the power input terminal 1 includes a neutral line and a live line. And a fuse F1 is connected to the live wire and is connected with the primary coil of the current transformer LX through a fuse F1. The fuse F1 can be fused when the output current is too large, thus playing a role in protection.
In one embodiment, the input circuit further includes a first diode D3 connected in series between the current transformer LX and the first resistor R1, and the first diode D3 is used for rectification.
In an embodiment, the input circuit further includes a first capacitor C1, a magnetic excitation coil LF1 and a rectifier B, one end of the first capacitor C1 is connected to the primary coil of the current transformer LX and the third pin of the magnetic excitation coil LF1, the fourth pin of the magnetic excitation coil LF1 and the other end of the first capacitor C1 are both connected to the zero line, the first pin and the second pin of the magnetic excitation coil LF1 are connected to the input end of the rectifier B, and the output end of the rectifier B is connected to the MOS transistor Q1. The first capacitor C1 is used for absorbing noise waves to realize interference resistance, the magnetic exciting coil LF1 and the first capacitor C1 are used for preventing the switching power supply from generating interference, and the input power supply transmitted to the transformer T1 can be rectified and filtered through the rectifier B for rectification.
In an embodiment, the rectifying and filtering circuit 2 includes a second capacitor C2, a third capacitor D3, and an inductor L1, two ends of the inductor L1 are respectively connected to the source of the MOS transistor Q1 and the transformer T1, two ends of the first capacitor C1 are respectively connected to the input end of the inductor L1 and the ground, and two ends of the second capacitor C2 are respectively connected to the output end of the inductor L1 and the ground. The second capacitor C2, the third capacitor D3 and the inductor L1 are used for filtering the power output by the MOS transistor Q1, and the stability of the output power is kept.
In an embodiment, the input circuit further includes a voltage dependent resistor LX, one end of the voltage dependent resistor LX is connected to the primary coil of the current transformer LX and the third pin of the magnetic excitation coil LF1, and the other end of the voltage dependent resistor LX is connected to the zero line. The voltage dependent resistor LX can suppress surge voltage, can be used for lightning stroke resistance and overvoltage protection, prevents voltage instability and plays a role in protection.
The above embodiments of the present invention are only described, and it should be noted that, for those skilled in the art, modifications can be made without departing from the inventive concept, but these all fall into the protection scope of the present invention.
Claims (7)
1. An input circuit of a switching power supply is characterized by comprising a power supply input end, a current transformer, a first resistor, a second resistor, an MOS (metal oxide semiconductor) tube and a rectifying and filtering circuit,
the power input end is connected with a rectifying and filtering circuit through a primary coil and an MOS tube on the current transformer in sequence; the first resistor and the second resistor are connected in series, and two ends of the first resistor and the second resistor after the first resistor and the second resistor are connected in series are respectively connected with two ends of a secondary coil on the current transformer; one end of a secondary coil on the current transformer is connected with the output end of the rectification filter circuit, and the grid of the MOS tube is respectively connected with a first resistor and a second resistor;
and the voltage generated by a secondary coil of the current transformer is divided by the first resistor and the second resistor and then the on-off of the MOS tube is controlled.
2. The input circuit of the switching power supply according to claim 1, wherein the power supply input terminals comprise a neutral line and a live line; and the live wire is connected with a fuse and is connected with a primary coil of the current transformer through the fuse.
3. The input circuit of the switching power supply according to claim 2, wherein the input circuit further comprises a first diode serially connected between the current transformer and the first resistor.
4. The input circuit of the switching power supply according to claim 3, wherein the input circuit further comprises a first capacitor, a magnetic excitation coil and a rectifier, one end of the first capacitor is connected to the primary coil of the current transformer and the third pin of the magnetic excitation coil, the fourth pin of the magnetic excitation coil and the other end of the first capacitor are both connected to a zero line, the first pin and the second pin of the magnetic excitation coil are connected to the input end of the rectifier, and the output end of the rectifier is connected to the MOS (metal oxide semiconductor) transistor.
5. The input circuit of the switching power supply according to claim 4, wherein the rectification filter circuit includes a second capacitor, a third capacitor and an inductor, two ends of the inductor are respectively connected to the source of the MOS transistor and the transformer, two ends of the first capacitor are respectively connected to the input end of the inductor and the ground, and two ends of the second capacitor are respectively connected to the output end of the inductor and the ground.
6. The input circuit of the switching power supply according to claim 5, further comprising a voltage dependent resistor, wherein one end of the voltage dependent resistor is connected to the primary coil of the current transformer and the third pin of the field coil, and the other end of the voltage dependent resistor is connected to a neutral line.
7. The input circuit of the switching power supply according to claim 6, wherein the MOS transistor is a P-channel MOS transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123154809.4U CN216437054U (en) | 2021-12-14 | 2021-12-14 | Input circuit of switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123154809.4U CN216437054U (en) | 2021-12-14 | 2021-12-14 | Input circuit of switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216437054U true CN216437054U (en) | 2022-05-03 |
Family
ID=81316793
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123154809.4U Active CN216437054U (en) | 2021-12-14 | 2021-12-14 | Input circuit of switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216437054U (en) |
-
2021
- 2021-12-14 CN CN202123154809.4U patent/CN216437054U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN207542770U (en) | A kind of DC over-voltage protection circuit and the power grid power supply voltage-stabilized power supply circuit for including it | |
| CN103474965A (en) | Low-cost alternating-current input overvoltage protection circuit and switching power supply | |
| CN104836419A (en) | Switching power supply driver chip supply circuit with undervoltage detection function | |
| CN104300794A (en) | Improved circuit of high-frequency switching power source | |
| CN216437054U (en) | Input circuit of switching power supply | |
| CN203491680U (en) | Automatic reset electric leakage overvoltage/undervoltage protection circuit | |
| CN114447899B (en) | Voltage doubling starting self-adaptive protection circuit and method for wireless charging system | |
| CN105576988B (en) | A kind of coupling energy taking power supply adapting to the work of wide dynamic range bus current | |
| CN205430069U (en) | Coupling draw -out power supply of adaptation wide dynamic range bus current work | |
| CN110138229B (en) | Double-tube flyback switching power supply with clamp protection | |
| CN104935190A (en) | Combined protection logic protection amplification type driving power supply for power system fault detection | |
| CN210518113U (en) | Double-tube flyback switching power supply with clamp protection | |
| CN204681075U (en) | A kind of power-down protection circuit | |
| CN2167784Y (en) | High-frequency conversion electrostatic power source arrangement | |
| CN210608945U (en) | Switch voltage transformation circuit and charger | |
| CN204030941U (en) | A kind of protective circuit and voltage stabilizing circuit | |
| CN216436806U (en) | Power input circuit with MOS manages surge protection function | |
| CN110912081A (en) | Motor overvoltage protection circuit and motor | |
| CN101854765B (en) | Ballast with automatic regulation of over-current protection point and lighting fixture thereof | |
| CN217721034U (en) | Switch power supply with overvoltage protection | |
| CN201399644Y (en) | Novel arc welding machine anti-electric shock protection device | |
| CN206533275U (en) | A kind of Switching Power Supply fed back based on invariable power | |
| CN104811026A (en) | Switch power supply | |
| CN215728556U (en) | Power supply protection circuit of cable on-line monitoring equipment | |
| CN2777817Y (en) | Protection circuit for single switch power |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |