CN210273874U - Novel water pump motor soft start control circuit - Google Patents
Novel water pump motor soft start control circuit Download PDFInfo
- Publication number
- CN210273874U CN210273874U CN201921458787.0U CN201921458787U CN210273874U CN 210273874 U CN210273874 U CN 210273874U CN 201921458787 U CN201921458787 U CN 201921458787U CN 210273874 U CN210273874 U CN 210273874U
- Authority
- CN
- China
- Prior art keywords
- circuit
- soft start
- resistor
- diode
- 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 relates to the technical field of frequency converters, and discloses a novel water pump motor soft start control circuit with small output voltage gradient and small voltage fluctuation, which comprises a limiting circuit, an oscillating circuit and a soft start circuit, wherein the input end of the limiting circuit is connected with a power supply end and is used for receiving a voltage signal of the power supply end and clipping the peak of the voltage signal; the input end of the oscillation circuit is coupled to the output end of the amplitude limiting circuit, and the oscillation circuit starts oscillation on a voltage signal input by the amplitude limiting circuit to form an oscillation signal; the input end of the soft start circuit is coupled with the output end of the oscillating circuit, and the soft start circuit receives the oscillating signal output from the oscillating circuit; the oscillation signal is used for driving a pulse signal output by the soft start circuit, and the pulse signal is used for triggering the switch tube to be conducted.
Description
Technical Field
The utility model relates to a converter technical field, more specifically say, relate to a novel water pump motor soft start control circuit.
Background
The frequency converter is a common device in the field of power frequency voltage regulation, and the frequency converter adjusts the frequency through the control circuit to change the output voltage, thereby realizing the soft start of the motor. In the past, the stability of the output voltage of the frequency converter during frequency adjustment is poor, so that the running voltage of the motor is unstable.
Therefore, in the prior art, a frequency converter with high output voltage stability is provided, which can effectively ensure that the motor operates under a stable voltage. However, in the existing inverter control circuit, in the process of outputting voltage by the inverter circuit, the slope of the voltage is large, the impact of the fluctuating voltage on the motor is large when the motor is started, and the insulation effect is reduced due to overheating of the motor coil when the motor is used for a long time.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model lies in, strike great defect when the above-mentioned fluctuating voltage to the motor start to prior art, provide a little and little novel water pump motor soft start control circuit of voltage fluctuation of output voltage slope.
The utility model provides a technical scheme that its technical problem adopted is: a novel water pump motor soft start control circuit is constructed, which comprises an amplitude limiting circuit, an oscillation circuit and a soft start circuit,
the input end of the amplitude limiting circuit is connected with a power supply end and is used for receiving a voltage signal of the power supply end and carrying out peak clipping on the voltage signal;
the input end of the oscillation circuit is coupled to the output end of the amplitude limiting circuit, and the oscillation circuit starts oscillation of the voltage signal input by the amplitude limiting circuit to form an oscillation signal;
the input end of the soft start circuit is coupled to the output end of the oscillating circuit, and the soft start circuit receives the oscillating signal output from the oscillating circuit;
the oscillation signal is used for driving a pulse signal output by the soft start circuit, and the pulse signal is used for triggering the switch tube to be conducted.
In some embodiments, the soft start circuit includes a controller, a first resistor, a second resistor, a first capacitor,
a power input end of the controller is connected with one end of the first resistor, the other end of the first resistor is connected with one end of the second resistor, and the other end of the second resistor is coupled to the power end;
the soft starting end of the controller is connected with one end of the first capacitor, and the other end of the first capacitor is connected with the common end.
In some embodiments, the oscillation circuit includes a third capacitor, a second diode, a fourth capacitor, a fifth resistor, and a third diode,
the third capacitor, the second diode and the fourth capacitor are connected in parallel, the cathode of the second diode is connected with one end of the fifth resistor and the power output end of the soft start circuit together,
the anode of the second diode is connected with the common end of the soft start circuit, and the other end of the fifth resistor is connected with the cathode of the third diode.
In some embodiments, the clipping circuit comprises a first diode, a fourth resistor, a second capacitor and a transformer,
the cathode of the first diode is commonly connected with one end of the fourth resistor and one end of the second capacitor, the other ends of the fourth resistor and the second capacitor are commonly connected with the power supply end and one end of the first primary winding of the transformer,
the anode of the first diode and the other end of the first primary winding are commonly connected with one end of the soft start circuit.
In some embodiments, the voltage regulator circuit includes a photo coupler, a three-terminal regulator, a twelfth resistor and a thirteenth resistor,
the input end of the photoelectric coupler is connected with one end of the twelfth resistor, and the other end of the twelfth resistor is connected with one end of the thirteenth resistor and the input end of the three-terminal voltage regulator tube;
and the output end of the photoelectric coupler is connected with the feedback voltage input end of the soft start circuit.
In some embodiments, the photoelectric coupler further comprises a sixth diode and a seventh diode, wherein the anode of the sixth diode is connected with the input end of the photoelectric coupler, the cathode of the sixth diode is connected with the anode of the seventh diode, and the cathode of the seventh diode is connected with the common end.
The novel soft start control circuit of the water pump motor comprises an amplitude limiting circuit, an oscillating circuit and a soft start circuit, wherein the input end of the amplitude limiting circuit is connected with a power supply end and is used for receiving a voltage signal of the power supply end and clipping the peak of the voltage signal; the input end of the oscillation circuit is coupled to the output end of the amplitude limiting circuit, and the oscillation circuit starts oscillation on a voltage signal input by the amplitude limiting circuit to form an oscillation signal; the input end of the soft start circuit is coupled with the output end of the oscillating circuit, and the soft start circuit receives the oscillating signal output from the oscillating circuit; the oscillation signal is used for driving a pulse signal output by the soft start circuit, and the pulse signal is used for triggering the switch tube to be conducted. Compared with the prior art, a starting pulse with a slightly narrow pulse width and gradually widened pulse width is generated in the soft starting circuit, the IGBT is controlled to work through the gradual conduction of the switching tube, the inverter circuit forms a slow starting process, and the inverter circuit and a load can be prevented from being damaged by impact current when the motor is started.
Drawings
The invention will be further explained with reference to the drawings and examples, wherein:
fig. 1 is a partial circuit diagram of an embodiment of a novel soft start control circuit of a water pump motor.
Detailed Description
In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Fig. 1 is a partial circuit diagram of an embodiment of a novel soft start control circuit of a water pump motor. As shown in fig. 1, the first embodiment of the novel soft start control circuit for a water pump motor of the present invention includes a soft start circuit 10, an oscillation circuit 20, a limiting circuit 30 and a switch tube. It should be noted that the switching tube may be a MOS tube, a field effect tube, or a triode. In this embodiment, a source (i.e., a MOS transistor, a field effect transistor) or an emitter (i.e., a triode) of the switching tube is connected to a gate of an inverter circuit (IGBT), an internal oscillator of the soft start circuit 10 generates a start pulse signal with a slightly narrower pulse width and gradually widened pulse width, and the switching tube is gradually started to operate, so that the switching tube has a slow start process, in which a PWM (pulse width modulation) signal output by a single chip or a main chip (not shown) is input into the inverter circuit through the switching tube, so that the IGBTs of the inverter circuit are alternately turned on, and a voltage output by the inverter circuit is slowly increased from 0V to a rated voltage (220V) to prevent an impulse current from breaking the IGBTs or damaging a load when the motor is started.
It should be noted that, the limiter circuit 30 is a circuit capable of smoothing the amplitude of the signal voltage within a limited range, and the limiter circuit 30 is commonly used for: shaping, such as clipping the interference at the top or bottom of the output waveform; waveform conversion, such as clipping positive pulses from the output signal, leaving only negative pulses therein; when overvoltage protection, such as peak output signals or interference, may damage the switching tube or the IGBT, the limiter circuit 30 may be connected in front of the switching tube or the IGBT, and the interference waveform at the top or bottom of the output waveform is cut by the limiter circuit 30.
The input end of the amplitude limiting circuit 30 is connected to the power supply end (220V) and is configured to receive a voltage signal of the power supply end, perform peak clipping on the voltage signal, and input the peak-clipped voltage signal to the oscillation circuit 20.
Specifically, the oscillation circuit 20 is configured to generate an oscillation current signal.
The input terminal of the oscillation circuit 20 is coupled to the output terminal of the amplitude limiting circuit 30, and the oscillation circuit 20 starts oscillation of the voltage signal input by the amplitude limiting circuit 30 to form an oscillation signal and outputs the oscillation signal to the soft start circuit 10.
The soft start circuit 10 has the advantages of small start current and stable and reliable start speed, and the start curve can be adjusted according to actual working conditions, so that the impact on the frequency converter when the motor is started is reduced, and the service life of a load can be prolonged.
Specifically, an input terminal of the soft-start circuit 10 is coupled to an output terminal of the oscillation circuit 20, and the soft-start circuit 10 receives the oscillation signal output from the oscillation circuit 20.
The oscillation signal is used for driving the soft start circuit 10 to output a pulse signal for triggering the conduction of the switch tube.
Specifically, the input end of the soft start circuit 10 is coupled to the output end of the oscillating circuit 20, the soft start circuit 10 receives the oscillating signal output from the oscillating circuit 20, the soft start circuit 10 is driven to operate by the oscillating signal, a start pulse signal with a slightly narrow and gradually widened pulse width is generated in the soft start circuit 10, and the switching tube is triggered to operate by the pulse signal, so that the IGBT of the inverter circuit has a slow start process, and the impact current generated when the motor is started is prevented from breaking the IGBT or damaging the load.
In some embodiments, in order to improve the control effect of the soft start of the motor, the controller U1, the first capacitor C1, the first resistor R1 and the second resistor R2 may be disposed in the soft start circuit 10. The controller U1 has perfect functions of overvoltage, overload overcurrent, undervoltage, overheat closing protection, undervoltage locking and PWM pulse signal output. It is equipped with 8 pins, is respectively: pin 1 is a soft start end; pin 2 is a voltage feedback input end; pin 3 is a current detection input terminal; the 4 pin and the 5 pin are drain electrodes of the switch tube; suspending the 6 feet in the air; pin 7 is a power input end; the 8 feet are public ends.
The first capacitor C1 is a soft start capacitor having a timing function and a capacity of 5 uF/200V. The first resistor R1 and the second resistor R2 have the function of limiting current, i.e., reducing the current of the power source terminal of the controller U1, and the resistance values thereof are set to 270K, respectively.
Specifically, the first resistor R1 is connected in series with the second resistor R2, the power input terminal of the controller U1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is coupled to the power source terminal (220V).
The soft start terminal of the controller U1 is connected to one terminal of the first capacitor C1, and the other terminal of the first capacitor C1 is connected to the common terminal.
The working principle is as follows: at the moment of starting the frequency converter, one path of direct-current voltage obtained by electrically rectifying and filtering the 220V mains supply is transmitted to pins 4 and 5 of the controller U1 through the transformer Tr1, and the other path of direct-current voltage is charged to the fourth capacitor C4 after passing through the starting resistor first resistor R1 and the second resistor R2, so that the voltage of the power supply input end of the controller U1 is increased. Meanwhile, the soft start end of the controller U1 charges an external soft start time constant capacitor (i.e., the first capacitor C1), when the voltage of the power input end (corresponding to 7 pins) is 5V and the voltage of the soft start end rises to 5.3V, the oscillating circuit 20 enters a normal working state, each internal functional circuit starts to work normally, and the high-frequency switching pulse output by the internal excitation circuit makes the field-effect power switching tube in a normal high-frequency switching state.
In some embodiments, in order to increase the width of the start pulse signal, a third capacitor C3, a second diode D2, a fourth capacitor C4, a fifth resistor R5 and a third diode D3 may be disposed in the oscillation circuit 20. Specifically, the third capacitor C3, the second diode D2 and the fourth capacitor C4 are connected in parallel, and the cathode of the second diode D2 is connected to one end of the fifth resistor R5 and the power output end of the controller U1 (belonging to the soft start circuit 10).
The anode of the second diode D2 is connected to the common terminal of the soft start circuit 10, the other end of the fifth resistor R5 is connected to the cathode of the third diode D3, the anode of the third diode D3 is connected to one end of the second primary winding N2 of the transformer, and the other end of the second primary winding N2 is connected to the common terminal of the soft start circuit 10 together with the anode of the second diode D2.
The working principle is as follows: when the voltage at the soft start end of the controller U1 rises to 5.3V, the oscillating circuit 20 enters a normal working state, the voltage at the two ends of the fourth capacitor C4 gradually rises, the fourth capacitor C4 automatically triggers the oscillator, the oscillator in the controller U1 generates a start pulse with a slightly narrow pulse width and gradually widened pulse width, the switching tube is gradually started to work, the IGBT of the inverter circuit has a slow starting process, and the impact current generated when the motor is started can be prevented from damaging the load.
It should be noted that, after the circuit starts oscillation, the circuit is locked in a normal oscillation state as long as the voltage at the power supply input terminal of the controller U1 is not lower than 8.5V.
In some embodiments, in order to reduce the magnitude of the spike pulse and protect the switching tube from the spike current, a first diode D1, a fourth resistor R4, a second capacitor C2 and a transformer Tr1 may be disposed in the limiter circuit 30. The cathode of the first diode D1 is commonly connected to one end of the fourth resistor R4 and one end of the second capacitor C2, and the other ends of the fourth resistor R4 and the second capacitor C2 are commonly connected to the power supply terminal (220V) and one end of the first primary winding N1 of the transformer Tr 1.
The anode of the first diode D1 and the other end of the first primary winding Tr1 are commonly connected to the switching tube drain (belonging to the soft start circuit 10) of the controller U1.
The working principle is as follows: the first diode D1, the second capacitor C2 and the fourth resistor R4 constitute a switch transistor drain spike absorption circuit. During the switching process of the on and off of the switching tube, the first primary winding N1 of the transformer Tr1 generates a high spike pulse to be applied to the drain of the switching tube, which is easy to cause the switching tube to break down due to overvoltage. Therefore, the amplitude of the spike pulse can be reduced by the pulse amplitude limiting circuit 30, so as to protect the switch tube from being broken down by the spike current.
In some embodiments, a voltage regulation circuit 40 may be provided in the circuit in order to ensure stability of the output voltage of the circuit. The voltage stabilizing circuit 40 comprises a photoelectric coupler U2, a three-terminal regulator U3, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a ninth capacitor C9, a twelfth resistor R12 and a thirteenth resistor R13.
An input end (corresponding to pin 1) of the photoelectric coupler U2 is connected with one end of a twelfth resistor R12 through a tenth resistor R10, and the other end of the twelfth resistor R12 is connected with one end of an eleventh resistor R11, one end of a thirteenth resistor R13 and an input end (corresponding to pin 1) of a three-terminal voltage regulator U3.
An output end (corresponding to 4 pins) of the photoelectric coupler U2 is connected with a feedback voltage input end (corresponding to 2 pins) of a controller U1 (belonging to the soft start circuit 10), an output end (corresponding to 3 pins) of the three-terminal voltage regulator tube U3 is connected with an output end (corresponding to 2 pins) of the photoelectric coupler U2 and one end of a ninth capacitor C9 together, and the other end of the ninth capacitor C9 is connected with the other end of an eleventh resistor R11 together.
The working principle is as follows: when the output voltage is increased due to some reason, the +5V output voltage is also increased, the voltage is divided by the twelfth resistor R12 and the thirteenth resistor R13 and then is correspondingly increased to the input end (corresponding to pin 1) of the three-terminal voltage regulator tube U3, so that the current flowing through the output end (corresponding to pin 2) and the common end (corresponding to pin 2) of the three-terminal voltage regulator tube U3 is increased, the light emission of the light emitting diode in the photoelectric coupler U2 is enhanced due to the increase of the current, the conduction of the phototriode is enhanced, the internal resistance is reduced, the voltage of the output end (corresponding to pin 4) of the photoelectric coupler U2 is reduced, and the voltage of the feedback voltage input end (corresponding to pin 2) of the controller U1 is reduced along with the increase. The pulse width control circuit in the controller U1 shortens the conduction time of the switch tube through pulse width adjustment, reduces the energy storage of the transformer Tr1, and reduces the output voltage, thereby achieving the purpose of stabilizing the output voltage.
In some embodiments, in order to ensure the stability of the output voltage of the circuit, a first inductor L1, an eleventh capacitor C11, a twelfth capacitor C12, a sixth diode D6, a seventh diode D7, a thirteenth capacitor C13, and a fifteenth resistor R15 may be disposed in the circuit. One end of a secondary winding N3 of the transformer Trl is connected to an anode of a sixth diode D6 through a first inductor L1, one end of a secondary winding N3 of the transformer Tr1 is connected to an input end (corresponding to pin 1) of a photocoupler U2 (belonging to a voltage stabilizing circuit 40) through a tenth resistor R10, a cathode of the sixth diode D6 is connected to an anode of a seventh diode D7, a cathode of the seventh diode D7 is connected to one end of a thirteenth capacitor C13, and the other end of the thirteenth capacitor C13 is connected to a common end.
One end of an eleventh capacitor C11 is commonly connected to the cathode of the fifth diode D5 and one end of the first inductor L1, one end of a twelfth capacitor C12 is commonly connected to the anode of the sixth diode D6 and the other end of the first inductor L1, and the other ends of the eleventh capacitor C11 and the twelfth capacitor C12 are commonly grounded.
The voltage output by the sixth diode D6 and the seventh diode D7 is divided into +12V and + 5V.
In some embodiments, in order to ensure the stability of the input circuit voltage, an overvoltage protection circuit may be further disposed in the circuit, and specifically, when the output voltage is too high due to a voltage rise or a runaway of the voltage stabilizing circuit 40, the voltage across the second primary winding N2 of the transformer Tr1 will also rise, and the voltage rectified by the third diode D3 and filtered by the fourth capacitor C4 is applied to the power input terminal (corresponding to pin 7) of the controller U1 to rise accordingly. When the voltage of the power supply input end (corresponding to the 7 pins) exceeds 16.5V, the overvoltage protection circuit in the controller U1 acts, the switch tube is cut off, and the power supply does not output, so that overvoltage protection is realized.
In some embodiments, in order to ensure the stability of the circuit current, an overcurrent protection circuit may be further provided in the circuit, specifically, a current detection input terminal (corresponding to pin 3) of the controller U1 is connected to the source (S pole) of the fet or the emitter of the triode, the current detection input terminal (corresponding to pin 3) of the controller U1 is connected to one end of the sixth resistor R6 and one end of the seventh resistor R7, wherein the sixth resistor R6 and the seventh resistor R7 are current sampling resistors on the source of the fet, when the current flowing through the source of the fet in the controller U1 is increased due to the overload or short circuit of the motor, the current flowing through the sixth resistor R6 and the seventh resistor R7 is correspondingly increased, the voltage drop across the current detection input terminal (corresponding to pin 3) of the controller U1 is increased, and when the potential of the current detection input terminal (corresponding to pin 3) of the controller U1 is increased to the threshold of the internal protection circuit of the controller U1, the internal protection circuit of the controller U1 works, the switching tube is cut off, and the voltage output of each group is 0V, so that the purpose of overcurrent protection is achieved.
While the embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many modifications may be made by one skilled in the art without departing from the spirit and scope of the present invention as defined in the appended claims.
Claims (6)
1. A novel water pump motor soft start control circuit is characterized by comprising an amplitude limiting circuit, an oscillating circuit and a soft start circuit,
the input end of the amplitude limiting circuit is connected with a power supply end and is used for receiving a voltage signal of the power supply end and carrying out peak clipping on the voltage signal;
the input end of the oscillation circuit is coupled to the output end of the amplitude limiting circuit, and the oscillation circuit starts oscillation of the voltage signal input by the amplitude limiting circuit to form an oscillation signal;
the input end of the soft start circuit is coupled to the output end of the oscillating circuit, and the soft start circuit receives the oscillating signal output from the oscillating circuit;
the oscillation signal is used for driving a pulse signal output by the soft start circuit, and the pulse signal is used for triggering the switch tube to be conducted.
2. The novel water pump motor soft start control circuit as claimed in claim 1, wherein the soft start circuit comprises a controller, a first resistor, a second resistor, a first capacitor,
a power input end of the controller is connected with one end of the first resistor, the other end of the first resistor is connected with one end of the second resistor, and the other end of the second resistor is coupled to the power end;
the soft starting end of the controller is connected with one end of the first capacitor, and the other end of the first capacitor is connected with the common end.
3. The novel water pump motor soft start control circuit as claimed in claim 1, wherein the oscillation circuit comprises a third capacitor, a second diode, a fourth capacitor, a fifth resistor and a third diode,
the third capacitor, the second diode and the fourth capacitor are connected in parallel, the cathode of the second diode is connected with one end of the fifth resistor and the power output end of the soft start circuit together,
the anode of the second diode is connected with the common end of the soft start circuit, and the other end of the fifth resistor is connected with the cathode of the third diode.
4. The novel soft start control circuit of the water pump motor as claimed in claim 1, wherein the amplitude limiting circuit comprises a first diode, a fourth resistor, a second capacitor and a transformer,
the cathode of the first diode is commonly connected with one end of the fourth resistor and one end of the second capacitor, the other end of the fourth resistor and the other end of the second capacitor are commonly connected with the power supply end and one end of the first primary winding of the transformer,
the anode of the first diode and the other end of the first primary winding are commonly connected with one end of the soft start circuit.
5. The novel soft start control circuit of the water pump motor as claimed in any one of claims 1 to 4, further comprising a voltage regulator circuit including a photoelectric coupler, a three-terminal regulator tube, a twelfth resistor and a thirteenth resistor,
the input end of the photoelectric coupler is connected with one end of the twelfth resistor, and the other end of the twelfth resistor is connected with one end of the thirteenth resistor and the input end of the three-terminal voltage regulator tube;
and the output end of the photoelectric coupler is connected with the feedback voltage input end of the soft start circuit.
6. The novel soft start control circuit of the water pump motor according to claim 5, further comprising a sixth diode and a seventh diode, wherein an anode of the sixth diode is connected to the input terminal of the photoelectric coupler, a cathode of the sixth diode is connected to an anode of the seventh diode, and a cathode of the seventh diode is connected to the common terminal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921458787.0U CN210273874U (en) | 2019-09-04 | 2019-09-04 | Novel water pump motor soft start control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921458787.0U CN210273874U (en) | 2019-09-04 | 2019-09-04 | Novel water pump motor soft start control circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210273874U true CN210273874U (en) | 2020-04-07 |
Family
ID=70018567
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921458787.0U Active CN210273874U (en) | 2019-09-04 | 2019-09-04 | Novel water pump motor soft start control circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210273874U (en) |
-
2019
- 2019-09-04 CN CN201921458787.0U patent/CN210273874U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104660022B (en) | The system and method that overcurrent protection is provided for supply convertor | |
| JP3707436B2 (en) | Switching power supply | |
| US6639811B2 (en) | Switching power supply unit | |
| TWI470911B (en) | Switch converting circuit and converting method | |
| JP4085335B2 (en) | Switching power supply | |
| WO1998047218A1 (en) | Switch-mode power supply with over-current protection | |
| US6738266B2 (en) | Switching power supply unit | |
| CN100423400C (en) | Low ripple high reliable high-capacity capacitance voltage stabilizing charging circuit | |
| JP2015053225A (en) | Led drive circuit | |
| JP3653075B2 (en) | Switching power transmission device | |
| KR101847321B1 (en) | Flyback switching power supply circuit and backlight driving device applying same | |
| CN210273874U (en) | Novel water pump motor soft start control circuit | |
| JP3691498B2 (en) | Self-excited switching power supply circuit | |
| CN203775499U (en) | LED (light-emitting diode) pulse drive circuit | |
| CN114221548B (en) | Precise Insulated Gate Bipolar Transistor (IGBT) grid drive isolation power supply | |
| CN114448227B (en) | Photovoltaic inverter system and regulating circuit thereof | |
| CN215498737U (en) | Wide-range voltage input direct-current power supply circuit | |
| CN210404738U (en) | Reverse connection prevention protection circuit for direct current input | |
| CN202268802U (en) | Switch conversion circuit and integrated circuit used therein | |
| US6016261A (en) | Switching voltage converter with synchronous rectification | |
| US8963429B2 (en) | Lighting apparatus for fluorescent tube and driving method therefor | |
| CN211239409U (en) | Photovoltaic power generation's storage control circuit | |
| CN214900670U (en) | Isolation voltage-stabilized power supply circuit | |
| CN217469911U (en) | IGBT protection circuit | |
| CN214315060U (en) | Flyback power circuit for electric automobile |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |