Feedback drive circuit of high-power semiconductor laser driving source
阅读说明：本技术 一种大功率半导体激光器驱动源的反馈驱动电路 (Feedback drive circuit of high-power semiconductor laser driving source ) 是由 张志� 黄见洪 林文雄 张江钿 于 2021-07-16 设计创作，主要内容包括：本发明公开了一种大功率半导体激光器驱动源的反馈驱动电路,属于激光器电源技术领域,能够实现对大功率半导体激光器的驱动。所述反馈驱动电路包括控制信号电路、调压驱动电路及反馈调节电路；所述控制信号电路用于接收输入信号并产生驱动信号,所述驱动信号用于驱动所述调压驱动电路输出电流及电压；所述控制信号电路还用于采集所述电压,并根据所述电压调整所述驱动信号；所述调压驱动电路还用于形成电流反馈信号；所述反馈调节电路用于采集所述电流反馈信号,并将所述电流反馈信号放大并传输给控制信号电路；所述控制信号电路还用于接收所述电流反馈信号并调整所述驱动信号。(The invention discloses a feedback drive circuit of a high-power semiconductor laser drive source, belongs to the technical field of laser power supplies, and can drive a high-power semiconductor laser. The feedback driving circuit comprises a control signal circuit, a voltage regulating driving circuit and a feedback regulating circuit; the control signal circuit is used for receiving an input signal and generating a driving signal, and the driving signal is used for driving the voltage regulating driving circuit to output current and voltage; the control signal circuit is also used for collecting the voltage and adjusting the driving signal according to the voltage; the voltage regulating driving circuit is also used for forming a current feedback signal; the feedback adjusting circuit is used for acquiring the current feedback signal, amplifying the current feedback signal and transmitting the amplified current feedback signal to the control signal circuit; the control signal circuit is further configured to receive the current feedback signal and adjust the driving signal.)
1. A feedback drive circuit of a high-power semiconductor laser drive source is characterized by comprising a control signal circuit (1), a voltage regulation drive circuit (2) and a feedback regulation circuit (3);
the control signal circuit (1) is used for receiving an input signal and generating a driving signal, and the driving signal is used for driving the voltage regulating driving circuit (2) to output current and voltage;
the control signal circuit (1) is also used for collecting the voltage and adjusting the driving signal according to the voltage;
the voltage regulation driving circuit (2) is also used for forming a current feedback signal;
the feedback adjusting circuit (3) is used for collecting the current feedback signal, amplifying the current feedback signal and transmitting the current feedback signal to the control signal circuit (1);
the control signal circuit (1) is further configured to receive the current feedback signal and adjust the driving signal.
2. The feedback driving circuit according to claim 1, wherein the control signal circuit (1) comprises a TL494 chip, the TL494 chip comprising 1-16 pins;
the control signal circuit (1) further comprises a fifth resistor, a sixth resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a second capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor and a first adjustable resistor;
one end of the ninth resistor is connected with the pin 1 of the TL494 chip, the other end of the ninth resistor is connected with one end of the fixed end of the first adjustable resistor, the other ends of the adjusting end and the fixed end of the first adjustable resistor are grounded, one end of the tenth resistor is connected with the pin 1 of the TL494 chip, the other end of the tenth resistor is connected with one end of the fifth capacitor and one end of the twelfth resistor, and the other end of the fifth capacitor and the other end of the twelfth resistor are used for being connected with an output end of a laser driving source;
one end of the fifth resistor is connected with the 2 pin of the TL494 chip, the other end of the fifth resistor is used for connecting a 5V direct current power supply, one end of the sixth resistor is connected with the 2 pin of the TL494 chip, and the other end of the sixth resistor is grounded;
one end of the second capacitor is connected with the 2 pin of the TL494 chip, the other end of the second capacitor is connected with one end of the eighth resistor, and the other end of the eighth resistor is connected with the 3 pin of the TL494 chip;
one end of the thirteenth resistor is connected with the 3 pin of the TL494 chip, the other end of the thirteenth resistor is connected with one end of the sixth capacitor, and the other end of the sixth capacitor is connected with the 15 pin of the TL494 chip;
the 5 pin of the TL494 chip is grounded through the fourth capacitor; the pin 6 of the TL494 chip is grounded through the eleventh resistor; the pins 7, 9 and 10 of the TL494 chip are grounded; the pins 13 and 14 of the TL494 chip are used for being connected with a 5V direct current power supply;
one end of the seventh capacitor is connected with the 15 pin of the TL494 chip, and the other end of the seventh capacitor is connected with the 16 pin of the TL494 chip.
3. The feedback drive circuit according to claim 2, wherein the control signal circuit (1) further comprises a second adjustable resistor, a third adjustable resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, an eighth capacitor;
one end of the fixed end of the second adjustable resistor is connected with the 15 pin of the TL494 chip and one end of the fifteenth resistor, the other end of the fixed end of the second adjustable resistor and the adjusting end of the second adjustable resistor are connected with the other end of the fifteenth resistor, and the connection between the fixed end of the second adjustable resistor and the fifteenth resistor is used for connecting the current feedback signal;
one end of the fourteenth resistor is connected with a connection point of fixed ends of the 15 pin of the TL494 chip, the fifteenth resistor and the second adjustable resistor, and the other end of the fourteenth resistor is used for connecting a 5V direct-current power supply;
one end of the sixteenth resistor is connected with a connection point of the 15 pin of the TL494 chip, the fifteenth resistor and the fourteen resistor, and the other end of the sixteenth resistor is grounded through the eighth capacitor; one end of the seventeenth resistor is connected with the 15 pin of the TL494 chip and the connection point of the sixteenth resistor, the other end of the seventeenth resistor is connected with one end of the eighteenth resistor and the adjusting end of the third adjustable resistor, the other end of the eighteenth resistor is grounded, one end of the fixed end of the third adjustable resistor is used for being connected with a 5V direct-current power supply, and the other end of the fixed end of the third adjustable resistor is grounded.
4. The feedback drive circuit according to claim 3, wherein the control signal circuit (1) further comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a seventh resistor, a first capacitor, a third capacitor, a diode, and a triode;
one end of the first resistor is connected with the 4 pins of the TL494 chip, and the other end of the first resistor is grounded; one end of the second resistor is connected with the 4 pins of the TL494 chip, and the other end of the second resistor is used for connecting a 5V direct-current power supply; the first capacitor C1 is connected in parallel with the second resistor R2; a collector of the triode is connected with the anode of the diode, the collector is connected with a 5V direct-current power supply through a seventh resistor, the collector is grounded through a third capacitor, a base is connected with the output end of the laser driving source through the third resistor, the base is grounded through the fourth resistor, and an emitter is grounded; the cathode of the diode is connected with the 4-pin of the TL494 chip.
5. The feedback driving circuit according to claim 3 or 4, wherein the voltage regulating driving circuit (2) comprises a transformer, a thirtieth resistor, a thirty-first resistor, a thirty-second resistor, a thirty-third resistor, a thirty-fourth resistor, a second transistor, a third transistor, a twelfth capacitor, a thirteenth capacitor, a second diode, a third diode, and a current sensor;
the transformer comprises pins 1-3 and pins 6-10, the source of the second transistor is connected with the anode of a twelfth capacitor, the anode of a thirteenth capacitor, the anode of a second diode and the source of a third transistor, the drain of the second transistor is connected with pin 1 of the transformer, the gate of the second transistor is used for being connected with pin 11 of the chip, the gate of the second transistor is connected with a power supply through the thirtieth resistor and is grounded through the thirty-first resistor, the second diode is grounded through the third diode, and the twelfth capacitor and the thirteenth capacitor are grounded in parallel;
the drain of the third transistor is connected with the pin 3 of the transformer, the gate of the third transistor is used for being connected with the pin 8 of the chip, the gate of the third transistor is connected to a power supply through the thirty-third resistor and is grounded through the thirty-fourth resistor;
a pin 2 of the transformer is connected with a power supply through the thirty-second resistor, pins 6 to 10 of the transformer are used for outputting converted voltage, and a pin 10 of the transformer is externally connected with the current sensor;
the current feedback signal is collected at the connection of the 10 pins of the transformer and the current sensor.
6. The feedback driving circuit according to claim 5, wherein the second transistor and the third transistor are both IRF640 field effect transistors.
7. The feedback driving circuit according to claim 5, wherein the feedback regulating circuit (3) is a two-stage amplifying circuit, an input end of the two-stage amplifying circuit is used for receiving the current feedback signal, and an output end of the two-stage amplifying circuit is connected with the 16 pins of the TL494 chip.
8. The feedback drive circuit according to claim 7, the feedback adjustment circuit (3) comprising a first op amp, a second op amp, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a ninth capacitor, a tenth capacitor and a fifth adjustable resistor;
the first transporting and placing device comprises 1, 2, 3, 4 and 8 pins, and the second transporting and placing device comprises 5, 6, 7, 9 and 10 pins;
the pin 2 of the first operational amplifier is connected with one end of a nineteenth resistor, a twenty-first resistor and a twenty-third resistor, the other end of the nineteenth resistor is used for accessing the current feedback signal, the other end of the twenty-first resistor is connected with the pin 1 of the first operational amplifier, the other end of the twenty-third resistor is connected with the pin 1 of the first operational amplifier through the ninth capacitor, one end of the twentieth resistor and one end of the twenty-second resistor are connected with the pin 3 of the first operational amplifier, the other ends of the twentieth resistor and the twenty-second resistor are grounded, the pin 4 of the first operational amplifier is grounded, the pin 8 of the first operational amplifier is connected with a power supply, the pin 1 of the first operational amplifier is connected with one end of the twenty-fourth resistor and one fixed end of the fifth adjustable resistor, and the other end of the twenty-fourth resistor is connected with the other fixed end of the fifth adjustable resistor and grounded, the adjusting end of the fifth adjustable resistor is connected with the 5-pin of the second operational amplifier;
the 6 feet of the second operational amplifier are grounded through a twenty-sixth resistor, the twenty-seventh resistor is connected with the tenth capacitor in parallel and is connected between the 6 feet and the 7 feet of the second operational amplifier, the 7 feet of the second operational amplifier are connected with one end of a twenty-eighth resistor, the other end of the twenty-eighth resistor is connected with the 16 feet of the TL494 chip, the 9 feet of the second operational amplifier are grounded, and the 10 feet of the second operational amplifier are connected with a power supply.
9. The feedback driver circuit according to claim 8, wherein the first and second op-amps are LM4562 chips.
10. The feedback driving circuit according to claim 7, wherein the feedback adjusting circuit (3) further includes a twenty-ninth resistor and an eleventh capacitor, the twenty-ninth resistor having one end connected to the eleventh capacitor in series and the other end connected to the output terminal of the two-stage amplifying circuit.
Technical Field
The invention relates to a feedback drive circuit of a high-power semiconductor laser driving source, and belongs to the technical field of laser power supplies.
Background
Compared with other lasers, the semiconductor laser has the advantages of small size, low cost, good stability and the like. The laser driving source is one of the most important technical equipments in the laser device as an electrical pumping source for generating laser energy, and is an important factor for determining the overall performance of the laser.
The laser driving source has a high requirement on the stability of the power supply, and an ordinary driving power supply cannot be used for driving the laser, so that a circuit special for driving the laser needs to be designed to drive the laser. With the continuous development of semiconductor lasers, the demand for high-power lasers is more and more strong, and the lasers all need large working current, so that the design of a driving source meeting the requirements of the high-power semiconductor lasers has important significance.
Disclosure of Invention
The invention provides a feedback drive circuit of a high-power semiconductor laser drive source, which can drive a high-power semiconductor laser.
The invention provides a feedback drive circuit of a high-power semiconductor laser driving source, which comprises a control signal circuit, a voltage regulation drive circuit and a feedback regulation circuit, wherein the control signal circuit is connected with the feedback regulation circuit;
the control signal circuit is used for receiving an input signal and generating a driving signal, and the driving signal is used for driving the voltage regulating driving circuit to output current and voltage;
the control signal circuit is also used for collecting the voltage and adjusting the driving signal according to the voltage;
the voltage regulating driving circuit is also used for forming a current feedback signal;
the feedback adjusting circuit is used for acquiring the current feedback signal, amplifying the current feedback signal and transmitting the amplified current feedback signal to the control signal circuit;
the control signal circuit is further configured to receive the current feedback signal and adjust the driving signal.
Optionally, the control signal circuit includes a TL494 chip, where the TL494 chip includes 1-16 pins;
the control signal circuit further comprises a fifth resistor, a sixth resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a second capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, and a first adjustable resistor;
one end of the ninth resistor is connected with the pin 1 of the TL494 chip, the other end of the ninth resistor is connected with one end of the fixed end of the first adjustable resistor, the other ends of the adjusting end and the fixed end of the first adjustable resistor are grounded, one end of the tenth resistor is connected with the pin 1 of the TL494 chip, the other end of the tenth resistor is connected with one end of the fifth capacitor and one end of the twelfth resistor, and the other end of the fifth capacitor and the other end of the twelfth resistor are used for being connected with an output end of a laser driving source;
one end of the fifth resistor is connected with the 2 pin of the TL494 chip, the other end of the fifth resistor is used for connecting a 5V direct current power supply, one end of the sixth resistor is connected with the 2 pin of the TL494 chip, and the other end of the sixth resistor is grounded;
one end of the second capacitor is connected with the 2 pin of the TL494 chip, the other end of the second capacitor is connected with one end of the eighth resistor, and the other end of the eighth resistor is connected with the 3 pin of the TL494 chip;
one end of the thirteenth resistor is connected with the 3 pin of the TL494 chip, the other end of the thirteenth resistor is connected with one end of the sixth capacitor, and the other end of the sixth capacitor is connected with the 15 pin of the TL494 chip;
the 5 pin of the TL494 chip is grounded through the fourth capacitor; the pin 6 of the TL494 chip is grounded through the eleventh resistor; the pins 7, 9 and 10 of the TL494 chip are grounded; the pins 13 and 14 of the TL494 chip are used for being connected with a 5V direct current power supply;
one end of the seventh capacitor is connected with the 15 pin of the TL494 chip, and the other end of the seventh capacitor is connected with the 16 pin of the TL494 chip.
Optionally, the control signal circuit further includes a second adjustable resistor, a third adjustable resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, and an eighth capacitor;
one end of the fixed end of the second adjustable resistor is connected with the 15 pin of the TL494 chip and one end of the fifteenth resistor, the other end of the fixed end of the second adjustable resistor and the adjusting end of the second adjustable resistor are connected with the other end of the fifteenth resistor, and the connection between the fixed end of the second adjustable resistor and the fifteenth resistor is used for connecting the current feedback signal;
one end of the fourteenth resistor is connected with a connection point of fixed ends of the 15 pin of the TL494 chip, the fifteenth resistor and the second adjustable resistor, and the other end of the fourteenth resistor is used for connecting a 5V direct-current power supply;
one end of the sixteenth resistor is connected with a connection point of the 15 pin of the TL494 chip, the fifteenth resistor and the fourteen resistor, and the other end of the sixteenth resistor is grounded through the eighth capacitor; one end of the seventeenth resistor is connected with the 15 pin of the TL494 chip and the connection point of the sixteenth resistor, the other end of the seventeenth resistor is connected with one end of the eighteenth resistor and the adjusting end of the third adjustable resistor, the other end of the eighteenth resistor is grounded, one end of the fixed end of the third adjustable resistor is used for being connected with a 5V direct-current power supply, and the other end of the fixed end of the third adjustable resistor is grounded.
Optionally, the control signal circuit further includes a first resistor, a second resistor, a third resistor, a fourth resistor, a seventh resistor, a first capacitor, a third capacitor, a diode, and a triode;
one end of the first resistor is connected with the 4 pins of the TL494 chip, and the other end of the first resistor is grounded; one end of the second resistor is connected with the 4 pins of the TL494 chip, and the other end of the second resistor is used for connecting a 5V direct-current power supply; the first capacitor C1 is connected in parallel with the second resistor R2; a collector of the triode is connected with the anode of the diode, the collector is connected with a 5V direct-current power supply through a seventh resistor, the collector is grounded through a third capacitor, a base is connected with the output end of the laser driving source through the third resistor, the base is grounded through the fourth resistor, and an emitter is grounded; the cathode of the diode is connected with the 4-pin of the TL494 chip.
Optionally, the voltage regulating driving circuit includes a transformer, a thirtieth resistor, a thirty-first resistor, a thirty-second resistor, a thirty-third resistor, a thirty-fourth resistor, a second transistor, a third transistor, a twelfth capacitor, a thirteenth capacitor, a second diode, a third diode, and a current sensor;
the transformer comprises pins 1-3 and pins 6-10, the source of the second transistor is connected with the anode of a twelfth capacitor, the anode of a thirteenth capacitor, the anode of a second diode and the source of a third transistor, the drain of the second transistor is connected with pin 1 of the transformer, the gate of the second transistor is used for being connected with pin 11 of the chip, the gate of the second transistor is connected with a power supply through the thirtieth resistor and is grounded through the thirty-first resistor, the second diode is grounded through the third diode, and the twelfth capacitor and the thirteenth capacitor are grounded in parallel;
the drain of the third transistor is connected with the pin 3 of the transformer, the gate of the third transistor is used for being connected with the pin 8 of the chip, the gate of the third transistor is connected to a power supply through the thirty-third resistor and is grounded through the thirty-fourth resistor;
a pin 2 of the transformer is connected with a power supply through the thirty-second resistor, pins 6 to 10 of the transformer are used for outputting converted voltage, and a pin 10 of the transformer is externally connected with the current sensor;
the current feedback signal is collected at the connection of the 10 pins of the transformer and the current sensor.
Optionally, the second transistor and the third transistor are both IRF640 field effect transistors.
Optionally, the feedback adjusting circuit is a two-stage amplifying circuit, an input end of the two-stage amplifying circuit is used for accessing the current feedback signal, and an output end of the two-stage amplifying circuit is connected to the 16 pins of the TL494 chip.
Optionally, the feedback adjusting circuit includes a first operational amplifier, a second operational amplifier, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a ninth capacitor, a tenth capacitor, and a fifth adjustable resistor;
the first transporting and placing device comprises 1, 2, 3, 4 and 8 pins, and the second transporting and placing device comprises 5, 6, 7, 9 and 10 pins;
the pin 2 of the first operational amplifier is connected with one end of a nineteenth resistor, a twenty-first resistor and a twenty-third resistor, the other end of the nineteenth resistor is used for accessing the current feedback signal, the other end of the twenty-first resistor is connected with the pin 1 of the first operational amplifier, the other end of the twenty-third resistor is connected with the pin 1 of the first operational amplifier through the ninth capacitor, one end of the twentieth resistor and one end of the twenty-second resistor are connected with the pin 3 of the first operational amplifier, the other ends of the twentieth resistor and the twenty-second resistor are grounded, the pin 4 of the first operational amplifier is grounded, the pin 8 of the first operational amplifier is connected with a power supply, the pin 1 of the first operational amplifier is connected with one end of the twenty-fourth resistor and one fixed end of the fifth adjustable resistor, and the other end of the twenty-fourth resistor is connected with the other fixed end of the fifth adjustable resistor and grounded, the adjusting end of the fifth adjustable resistor is connected with the 5-pin of the second operational amplifier;
the 6 feet of the second operational amplifier are grounded through a twenty-sixth resistor, the twenty-seventh resistor is connected with the tenth capacitor in parallel and is connected between the 6 feet and the 7 feet of the second operational amplifier, the 7 feet of the second operational amplifier are connected with one end of a twenty-eighth resistor, the other end of the twenty-eighth resistor is connected with the 16 feet of the TL494 chip, the 9 feet of the second operational amplifier are grounded, and the 10 feet of the second operational amplifier are connected with a power supply.
Optionally, the first and second loaders are LM4562 chips.
Optionally, the feedback adjusting circuit further includes a twenty-ninth resistor and an eleventh capacitor, one end of the twenty-ninth resistor is connected to the ground in series with the eleventh capacitor, and the other end of the twenty-ninth resistor is connected to the output end of the two-stage amplifying circuit.
The invention can produce the beneficial effects that:
the feedback drive circuit provided by the invention has the advantages of continuously adjustable current, overvoltage and overcurrent protection, high efficiency, wide application to a drive source of a semiconductor laser, and particular suitability for a high-power semiconductor drive source which needs large current drive;
the feedback driving circuit provided by the invention has the advantages that the working frequency is adjustable within 30kHz-200kHz, the duty ratio is adjustable within 10% -85%, the current is adjustable within 0A-18A, the adjustability and the expansibility are strong, and the feedback driving circuit can be applied to different occasions;
the feedback adjusting circuit of the feedback driving circuit provided by the invention performs secondary amplification on a current feedback signal through the first operational amplifier and the second operational amplifier; the twenty-ninth resistor and the eleventh capacitor are grounded in series, so that the amplified signal is filtered; and a feedback regulation circuit is optimized, and the precision and the stability of output current are improved.
Drawings
Fig. 1 is a block diagram of a feedback driving circuit according to an embodiment of the present invention;
fig. 2 is a circuit diagram of a control signal circuit of a feedback driving circuit according to an embodiment of the present invention;
fig. 3 is a circuit diagram of a voltage regulation driving circuit of a feedback driving circuit according to an embodiment of the present invention;
fig. 4 is a circuit diagram of a feedback adjusting circuit of the feedback driving circuit according to an embodiment of the present invention.
List of parts and reference numerals:
1. a control signal circuit; 2. a voltage regulation drive circuit; 3. a feedback regulation circuit.
Detailed Description
The present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.
As shown in fig. 1, an embodiment of the present invention provides a feedback driving circuit of a driving source of a high-power semiconductor laser, including a control signal circuit 1, a voltage-regulating driving circuit 2, and a feedback regulating circuit 3;
the control signal circuit 1 is used for receiving an input signal and generating a driving signal, and the driving signal is used for driving the voltage regulating driving circuit 2 to output current and voltage;
the control signal circuit 1 is also used for collecting voltage and adjusting a driving signal according to the voltage;
the voltage regulation driving circuit 2 is also used for forming a current feedback signal ICHECK;
the feedback adjusting circuit 3 is used for acquiring a current feedback signal ICHECK, amplifying the current feedback signal ICHECK and transmitting the current feedback signal ICHECK to the control signal circuit 1;
the control signal circuit 1 is also configured to receive the current feedback signal ICHECK and adjust the driving signal.
The feedback drive circuit of the invention realizes the voltage and current control of a closed loop, and finally converts an input signal into an output which can be used by a laser.
As shown in fig. 2, the control signal circuit 1 includes a TL494 chip, and the TL494 chip includes 1 pin-16 pins;
the control signal circuit 1 further includes a fifth resistor R5, a sixth resistor R6, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a second capacitor C2, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, and a first adjustable resistor VR 1;
one end of a ninth resistor R9 is connected with pin 1 of the TL494 chip, the other end is connected with one end of the fixed end of a first adjustable resistor VR1, the adjusting end and the other end of the fixed end of the first adjustable resistor VR1 are grounded, one end of a tenth resistor R10 is connected with pin 1 of the TL494 chip, the other end is connected with one end of a fifth capacitor C5 and one end of a twelfth resistor R12, and the other end of the fifth capacitor C5 and the other end of the twelfth resistor R12 are used for being connected with the output end VO + of the laser driving source;
one end of a fifth resistor R5 is connected with the 2 pin of the TL494 chip, the other end of the fifth resistor R5 is used for connecting a 5V direct current power supply, one end of a sixth resistor R6 is connected with the 2 pin of the TL494 chip, and the other end of the sixth resistor R6 is grounded;
one end of a second capacitor C2 is connected with the 2 pin of the TL494 chip, the other end is connected with one end of an eighth resistor R8, and the other end of an eighth resistor R8 is connected with the 3 pin of the TL494 chip;
one end of a thirteenth resistor R13 is connected with the 3 pin of the TL494 chip, the other end is connected with one end of a sixth capacitor C6, and the other end of the sixth capacitor C6 is connected with the 15 pin of the TL494 chip;
the 5 pin of the TL494 chip is grounded through a fourth capacitor C4; the 6 pin of the TL494 chip is grounded through an eleventh resistor R11; pins 7, 9 and 10 of the TL494 chip are grounded; pins 13 and 14 of the TL494 chip are used for connecting with a 5V direct current power supply;
the seventh capacitor C7 has one end connected to the 15 pin of the TL494 chip and the other end connected to the 16 pin of the TL494 chip.
As shown in fig. 2, the control signal circuit 1 further includes a second adjustable resistor VR2, a third adjustable resistor VR3, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, and an eighth capacitor C8;
one end of the fixed end of the second adjustable resistor VR2 is connected to the 15 pin of the TL494 chip and one end of the fifteenth resistor R15, the other end of the fixed end of the second adjustable resistor VR2 and the adjusting end are connected to the other end of the fifteenth resistor R15, and the connection between the fixed end of the second adjustable resistor VR2 and the adjusting end of the fifteenth resistor R15 is used for receiving the current feedback signal ICHECK;
one end of a fourteenth resistor R14 is connected with a connection point of fixed ends of a pin 15 of the TL494 chip, a fifteenth resistor R15 and a second adjustable resistor VR2, and the other end of the fourteenth resistor R14 is used for connecting a 5V direct-current power supply;
one end of a sixteenth resistor R16 is connected with the connection point of the 15 pin of the TL494 chip, the fifteenth resistor R15 and the fourteen resistor, and the other end is grounded through an eighth capacitor C8; one end of a seventeenth resistor R17 is connected to the connection point of the pin 15 of the TL494 chip and the sixteenth resistor R16, the other end of the seventeenth resistor R17 is connected to one end of an eighteenth resistor R18 and the adjusting end of the third adjustable resistor VR3, the other end of the eighteenth resistor R18 is grounded, one end of the fixed end of the third adjustable resistor VR3 is used for being connected to a 5V DC power supply, and the other end of the fixed end is grounded.
A circuit formed by the first adjustable resistor VR1, the fifth resistor R5, the sixth resistor R6, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the twelfth resistor R12, the thirteenth resistor R13, the second capacitor C2, the fifth capacitor C5 and the sixth capacitor C6 is a voltage feedback circuit.
A circuit formed by the second adjustable resistor VR2, the third adjustable resistor VR3, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16, the seventeenth resistor R17, the eighteenth resistor R18 and the eighth capacitor C8 is an overcurrent protection circuit.
The voltage of the output terminal VO + of the laser driving source is divided by the first adjustable resistor VR1, the ninth resistor R9, the tenth resistor R10 and the twelfth resistor R12, and then is output to pin 1 of the TL494 chip of the control signal circuit 1 through the connection between the ninth resistor R9 and the tenth resistor R10; the 5V direct current power supply is divided by a fifth resistor R5 and a sixth resistor R6 and then is output to a pin 2 of a TL494 chip of the control signal circuit 1 as a reference signal; the current feedback signal ICHECK is amplified by the feedback regulating circuit 3 and then input to a 16 pin of a TL494 chip of the control signal circuit 1; the current feedback signal ICHECK passes through the second adjustable resistor VR2 and the fifteenth resistor R15 which are connected in parallel, and then is input to the 15 pin of the TL494 chip of the control signal circuit 1 as a limiting signal; the control signal circuit 1 changes the output pulse widths of the 8 pin and the 11 pin of the TL494 chip by using the obtained output voltage signal and output current signal, so as to realize the feedback control of the output; the regulation of the output voltage can be realized by regulating the first adjustable resistor VR1, and the regulation of the output current can be realized by regulating the second adjustable resistor VR 2; pins 5 and 6 of the TL494 chip set the oscillation frequency.
As shown in fig. 2, the control signal circuit 1 further includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a seventh resistor R7, a first capacitor C1, a third capacitor C3, a diode D1, and a transistor Q1;
one end of a first resistor R1 is connected with the 4 pin of the TL494 chip, and the other end is grounded; one end of a second resistor R2 is connected with the 4 pin of the TL494 chip, and the other end is used for connecting a 5V direct current power supply; the first capacitor C1C1 is connected in parallel with the second resistor R2R 2; a collector of the triode Q1 is connected with the anode of the diode D1, the collector is connected with a 5V direct-current power supply through a seventh resistor R7, the collector is grounded through a third capacitor C3, a base is connected with the output end VO + of the laser driving source through a third resistor R3, the base is grounded through a fourth resistor R4, and an emitter is grounded; the cathode of diode D1 is connected to the 4-pin of the TL494 chip.
The second capacitor C2, the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7 and the eighth capacitor C8 are all nonpolar capacitors
The 4-pin TL494 chip sets the dead time.
As shown in fig. 2 and 3, the voltage regulation driving circuit 2 includes a transformer TRAN1, a thirtieth resistor R30, a thirty-first resistor R31, a thirty-second resistor R32, a thirty-third resistor R33, a thirty-fourth resistor R34, a second transistor Q2, a third transistor Q3, a twelfth capacitor C12, a thirteenth capacitor C13, a second diode D2D1, a third diode D3D1, and a current sensor SEN;
transformer TRAN1 includes pins 1-3 and pins 6-10, the source of second transistor Q2 is connected to the positive pole of twelfth capacitor C12, the positive pole of thirteenth capacitor C13, the positive pole of second diode D2D1 and the source of third transistor Q3, the drain of second transistor Q2 is connected to pin 1 of transformer TRAN1, the gate of second transistor Q2 is used to connect to pin 11 of the chip, the gate of second transistor Q2 is connected to power VIN via thirtieth resistor R30, and is connected to ground via thirty-first resistor R31, second diode D2D1 is connected to ground via third diode D3D1, and twelfth capacitor C12 is connected to ground in parallel with thirteenth capacitor C13;
the drain of the third transistor Q3 is connected to pin 3 of the transformer TRAN1, the gate of the third transistor Q3 is used for being connected to pin 8 of the chip, the gate of the third transistor Q3 is connected to the power supply VIN through a thirteenth resistor R33, and is connected to the ground through a fourteenth resistor R34;
a pin 2 of the transformer TRAN1 is connected to a power supply VIN through a third twelve resistor R32, pins 6 to 10 of the transformer TRAN1 are used for outputting converted voltage, namely, the pin 6 to 10 of the transformer TRAN1 is externally connected with a load, and a pin 10 of the transformer TRAN1 is externally connected with a current sensor SEN;
the current feedback signal ICHECK is collected at the junction of pin 10 of transformer TRAN1 and current sensor SEN.
Signals of pins 8 and 11 of the TL494 chip of the control signal circuit 1 are input to the second transistor Q2 and the third transistor Q3, so that the second transistor Q2 and the third transistor Q3 are turned on in turn, and the transformer TRAN1 is controlled to realize voltage conversion. The second transistor Q2 and the third transistor Q3 are both IRF640 field effect transistors.
The feedback driving circuit reads the current feedback signal ICHECK when the circuit outputs, controls the output of the circuit according to the current feedback signal ICHECK, and switches the voltage feedback circuit to control the circuit output when the current feedback signal ICHECK possibly reaches a limit value when the load changes.
As shown in fig. 2 to 4, the feedback regulating circuit 3 is a two-stage amplifying circuit, an input end of the two-stage amplifying circuit is used for receiving the current feedback signal ICHECK, and an output end of the two-stage amplifying circuit is connected to the 16 pins of the TL494 chip.
The feedback adjusting circuit 3 comprises a first operational amplifier U1A, a second operational amplifier U1B, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a twenty-eighth resistor R28, a ninth capacitor C9, a tenth capacitor C10 and a fifth adjustable resistor VR 5;
the first conveyor U1A comprises legs 1, 2, 3, 4 and 8, and the second conveyor U1B comprises legs 5, 6, 7, 9 and 10;
the pin 2 of the first operational amplifier U1A is connected with one end of a nineteenth resistor R19, a twenty-first resistor R21 and a twenty-third resistor R23, the other end of the nineteenth resistor R19 is used for accessing a current feedback signal ICHECK, the other end of the twenty-first resistor R21 is connected with the pin 1 of the first operational amplifier U1A, the other end of the twenty-third resistor R23 is connected with the pin 1 of the first operational amplifier U1A through a ninth capacitor C9, one end of the twentieth resistor R20 and the twenty-second resistor R22 is connected with the pin 3 of the first operational amplifier U1A, the other end of the twentieth resistor R20 and the twenty-second resistor R22 is grounded, the pin 4 of the first operational amplifier U1A is grounded, the pin 8 of the first operational amplifier U1A is connected with a power supply VCC, the pin 1 of the first operational amplifier U1A is connected with one end of the twenty-fourth resistor R24 and one end of the fifth adjustable resistor VR5, the other end of the twenty-fourth resistor VR 24 is connected with a fixed end of the fifth adjustable resistor VR 57324, the adjusting end of a fifth adjustable resistor VR5 is connected with the 5 feet of the second operational amplifier U1B;
the pin 6 of the second operational amplifier U1B is grounded through a twenty-sixth resistor R26, a twenty-seventh resistor R27 is connected in parallel with a tenth capacitor C10 and is connected between the pin 6 and the pin 7 of the second operational amplifier U1B, the pin 7 of the second operational amplifier U1B is connected with one end of a twenty-eighth resistor R28, the other end of the twenty-eighth resistor R28 is connected with the pin 16 of the TL494 chip, the pin 9 of the second operational amplifier U1B is grounded, and the pin 10 of the second operational amplifier U1B is connected to a power supply VCC.
The ninth capacitor C9, the tenth capacitor C10, and the eleventh capacitor C11 are all nonpolar capacitors.
The first and second loaders U1A and U1B are LM4562 chips.
The feedback adjustment circuit 3 further includes a twenty-ninth resistor R29 and an eleventh capacitor C11, wherein one end of the twenty-ninth resistor R29 is connected in series with the eleventh capacitor C11 to the ground, and the other end is connected to the output end of the two-stage amplification circuit.
Weak current feedback signals ICHECK are amplified for the first time through a first operational amplifier U1A, the current feedback signals ICHECK after the first amplification are amplified for the second time through a second operational amplifier U1B, the current feedback signals ICHECK after the first amplification are grounded in series through a twenty-ninth resistor R29 and an eleventh capacitor C11, filtering of the amplified signals is achieved, the current feedback signals ICHECK after the second amplification are input to an LM4562 chip finally, closed-loop feedback control is achieved, and accuracy and stability of output current are improved.
The feedback drive circuit provided by the invention has the advantages of continuously adjustable current, overvoltage and overcurrent protection and high efficiency, is widely applied to a drive source of a semiconductor laser, and is particularly suitable for a high-power semiconductor drive source which needs large current to drive.
The feedback driving circuit provided by the invention has the advantages that the working frequency is adjustable within 30kHz-200kHz, the duty ratio is adjustable within 10% -85%, the current is adjustable within 0A-18A, the adjustability and the expansibility are strong, and the feedback driving circuit can be applied to different occasions.
Although the present application has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application.