The inertial measurement M-combination system IMU is the most important component of the inertial guidance system. The power supply is the heart of the MU and is the power of all electronic devices. The utility model has the characteristics of the power voltage frequency frequency noise loading parameter variation, the volumetric weight form efficiency reliability and the like, and thus has various forms. The excellent performance index of the power supply will have a good impact on the IMU system. The power efficiency of the power supply will directly affect the power efficiency of the whole machine. The stability ripple of the output voltage of the power supply will directly affect the accuracy of the system. The size will directly affect the weight of the whole machine, and the quality of the power supply design will directly affect the pros and cons of the whole machine. The power supply is a high-frequency, high-efficiency modular converter. Its switching power conversion technology has been greatly developed in recent years, and has been widely recognized by various industries and is becoming more and more popular in various power electronic devices. An inertial measurement system is a combination of the power box electronic box rest, its volume is reduced, the weight is greatly reduced, the measurement range is relatively high, and the measurement angular rate is as high as 350=5. Corresponding to the performance index of the DC power supply is proposed. High requirements, especially the gyro power supply voltage requirements of 65, 3 people, on the 200 parent 12 small board to convert 12 DC output, the total output power reached more than 200 watts, part of the output delay. The self-excited and pulse-width lock-up circuit open-loop relies on the regulator's old-fashioned power supply, which is a big and cumbersome and powerless. Not only is it difficult to output high-power, but there are no more than a dozen power regulators. The electromagnetic feedback type switching power supply adopts the magnetic feedback link. By adjusting the pulse width of the control switch tube, the output voltage is constant, and its exquisite and sleek design effectively solves this problem, not only satisfies the overall index requirements in function, but also The performance has been greatly improved, and it is a practical 070 converter, which has been applied in the inertial measurement system.
Circuit working principle Electromagnetic feedback type switching power supply adopts push-pull type, 1 scheme, adopts self-cutting start-up and electromagnetic feedback signal, uses low-power high-power VMOS tube as switch execution device, pulse width modulator TL494 as control circuit, super fast Restore the rectifier rectification, and have the characteristics of efficiency and stability. The electromagnetic feedback type switching power supply is its exciting multi-output DC source. Its circuit structure is divided into 6 cut-off start circuit, pulse width modulation control circuit, and delay. Circuit, signal amplification switch circuit, feedback circuit, transformer, rectifier circuit, filter circuit, etc. Power principle box 1.
Electromagnetic feedback type switching power supply for the process. After power-on, the input network filters the input voltage to eliminate the input AC component. The startup circuit is started, the output is 15, and the voltage is supplied to the D1494 control circuit. A pulse width modulator 1494 and corresponding scales form a control circuit that produces a rectangular wave that is adjustable in phase opposite pulse width. The delay circuit generates a delay control signal after power-on, so that the operation of the control circuit is delayed. The control circuit outputs a rectangular wave to be amplified by the emitter follower, which pushes the switch circuit transformer to work. The output voltage of the transformer is filtered by the rectifier rectifier filter. After the transformer is started, the feedback circuit feedback voltage is supplied to the control circuit to cut off the startup circuit. At the same time, the control circuit outputs the rectangular wave pulse width to constant the transformer output voltage. The role.
Electromagnetic feedback type, off power supply, switching loss is relatively small, the primary side of the transformer is connected in push-pull form, the voltage voltage of the collector of the power switch tube is twice the input voltage, the high-power converter suitable for low-voltage input, the two-way rectangle with opposite phase The wave drives two power switch tubes to be alternately turned on. The feedback voltage modulates the drive wave pulse width through the control circuit, adjusts the duty ratio, and keeps the output voltage constant. When the load is constant, the output voltage is determined by the following formula: tO drive wave duty Ratio, 0 output voltage vv input voltage switch tube conduction time 101 switch tube off time dead time time transformer primary side turns transformer secondary side turns electromagnetic feedback type switch source consists of pulse width modulator 7494 and corresponding ruler 0 The air ratio control circuit 1 pulse width modulator 494 contains an oscillator, the oscillation frequency is determined by the external resistance core, and can be used as an external voltage control or soft start control, and the other end of the comparator is connected to the output terminal of the error amplifier. The error amplifier is a differential input amplifier. The non-inverting input terminal is connected to the internal voltage of the 1494 reference voltage divider. The inverting input terminal is connected to the voltage divider of the transformer feedback. The output pin sensitive voltage is compared with the sawtooth wave, and the output widened rectangular wave is output. 2, the rectangular wave is divided by a 1 flip-flop, the NAND gate is transformed, the pole tube current is amplified, and the output is switched between the two phases with a dead zone.
Performance characteristics Electromagnetic feedback type switching power supply realizes high-power 0,0 conversion, the power output power can reach more than 200 ash, and the efficiency can reach 70 or more. The working frequency of the power supply is high, and it is 20 volumes and 2 or more. The corresponding filter capacitor is small, and the circuit board is small in size and light in weight.
By using electromagnetic feedback, the pulse width is adjusted to stabilize the voltage, the voltage and load regulation rate are relatively high, a large number of voltage regulators are removed, the cost is reduced, the volume is reduced, and the circuit and the structure of the platform are simplified, and the system is improved. Reliability ensures a small design goal.
The control circuit uses electromagnetic feedback to supply power from the cut-off circuit. The start-up circuit 3 has a large output feedback circuit and a high tube requirement. The tube often works in the limit parameter state, the tube heat is easily damaged, and the reliability is very low.
With the 3 start-up circuit, after the input is powered up, the regulator tube provides a bias voltage for the pole tube, and the pole tube conducts to provide the working voltage for the control circuit. When the transformer works, the feedback circuit feedback voltage raises the pole tube. The emitter voltage is cut to 1 for the control circuit, and the feedback voltage is also used for the control circuit. Pulse width modulation does not need to set a dedicated dry pulse width modulation feedback circuit, which greatly reduces power consumption and improves Reliability.
When the input voltage of the circuit is reversed, the primary winding of the transformer and the power switch tube form an internal short circuit to the input, the starting circuit cannot be started, and the whole converter does not work. The experiment proves that the high current of 15 people does not make the transformer and the minute. The switch tube is damaged, so that it can protect me.
Rectifier mining, full-wave rectification, negative output common winding, the negative terminal only needs to reverse the rectifier tube, not only can balance the output voltage, but also use less than half of the bridge rectifier tube, the power consumption is reduced by half, the output loop The resistance in the middle is also reduced, which is beneficial to the voltage output.
The circuit has a delayed start function, and it is no longer necessary to design a delay switch for systems that need to work asynchronously. Some systems have power supply timing requirements. For example, an inertial measurement system requires a gyro-closed power supply to be delayed by 5 seconds than the motor power supply. If an electromagnetic relay is used to control the switch, the cost is high, the reliability is poor, and the delay time is not easy to adjust. If the time is too short, the gyro in the combination will have a shelling phenomenon due to the competition of the power supply timing. If the delay time is too long, the reaction time of the inertial combination will be lengthened. The delay circuit composed of the resistor scale capacitor 0 and the inverter not only has a simple circuit structure and high reliability, but also has a delay time of ä¸=foot, which can be easily debugged with the whole machine, and only needs to adjust the resistance ruler to obtain the It takes time.
The emitter follower improves the driving waveform, which not only reduces the power consumption of the switching tube, but also prevents the push-pull tube from being turned on at the same time, improving reliability. 105 tube input impedance is very high, the output impedance of the drive circuit must be relatively low, in order to suppress the oscillation component in the drive wave, reduce the rise time and fall time of the drive wave, and make the push wave more regular to adapt to faster switching speed. The power consumption of the switch tube is greatly reduced to prevent its overheating breakdown. Although the output stage of Ding 1494 is a pole tube, its switching time is not conducive to the discharge of the parasitic capacitance of the 05-gate end, and the addition of a stepped emitter follower between the stomach and the 5 tube can greatly drive the waveform. Improvement, 5. The tube source is connected to the inductor, which is an effective application of the zero voltage switching technology. During the turn-on or turn-off of the VMOS transistor, due to the influence of its output parasitic capacitance, the current rises and the voltage drops or the current drops. There is an overlap process in the voltage rise, which causes the power tube to generate a fixed loss. The series inductance and the parasitic capacitance of the switch tube form a series resonance, which effectively suppresses the overlap process and reduces the power consumption of the switch tube.
The experimental results in the switching power supply, the on-resistance determines, the output voltage and loss of the switch, the tube with small on-resistance, the higher the efficiency of turning off the power supply, due to the push-pull method, the cut-off voltage of the switch tube is the input voltage of two Double, considering the derating, the withstand voltage of the switch tube should be about double the input voltage, then the tube with high on-resistance and high withstand voltage should be used, but the tube with high withstand voltage has large on-resistance. At the same time, the gate terminal voltage rises and the on-resistance decreases. Excessive loss of the switching tube will limit the power output of the converter, so it should be considered when selecting the switching tube.
As a rectifying power pole of the power supply, it should have a small forward voltage drop, a small reverse leakage current, and a small reverse recovery time. The forward conduction voltage drop affects the conduction loss of the pole tube until the efficiency of the converter. The reverse recovery time will affect the operating frequency of the switching power supply. Although the Schottky base tube has the above holding point, its reverse cutoff voltage is low. , below 100, the ultra-fast recovery rectifier tube rectification characteristics are worse than the Schottky base tube, but its reverse cut-off voltage is higher, which is an ideal choice. Improper selection of the pole tube will directly affect the output power of the converter. In the electromagnetic feedback type switching power supply, the parallel ultra-fast recovery pole tube rectification is adopted to improve the rectification characteristics.
Electromagnetic feedback type switching power supply can meet the performance requirements of miniaturization and high power. The output voltage is stable and the reliability is high. The output voltage of the converter can be easily adjusted by the resistor to achieve the required value.
The following is the test data of the group ±50V and ±15V output voltage, the input voltage is 27 soil 4V, when the output power is 100, the input voltage adjustment does not change, the load adjustment voltage is less than 3, the ripple is maximum 160, the efficiency Up to 75.
Input Voltage Load Output Voltage Load Output Voltage Load Output Voltage Load Output Voltage Conclusion The application of switching power supply technology in the world is becoming more and more popular and attracts more and more attention. Electromagnetic feedback type switching power supply is a kind of excellent, 70 converter, simple circuit structure, high reliability, low cost, output voltage can be set according to requirements, debugging is also very convenient, its high power and high efficiency can be extended When starting up, etc., it is used in power electronics.
Circuit working principle Electromagnetic feedback type switching power supply adopts push-pull type, 1 scheme, adopts self-cutting start-up and electromagnetic feedback signal, uses low-power high-power VMOS tube as switch execution device, pulse width modulator TL494 as control circuit, super fast Restore the rectifier rectification, and have the characteristics of efficiency and stability. The electromagnetic feedback type switching power supply is its exciting multi-output DC source. Its circuit structure is divided into 6 cut-off start circuit, pulse width modulation control circuit, and delay. Circuit, signal amplification switch circuit, feedback circuit, transformer, rectifier circuit, filter circuit, etc. Power principle box 1.
Electromagnetic feedback type switching power supply for the process. After power-on, the input network filters the input voltage to eliminate the input AC component. The startup circuit is started, the output is 15, and the voltage is supplied to the D1494 control circuit. A pulse width modulator 1494 and corresponding scales form a control circuit that produces a rectangular wave that is adjustable in phase opposite pulse width. The delay circuit generates a delay control signal after power-on, so that the operation of the control circuit is delayed. The control circuit outputs a rectangular wave to be amplified by the emitter follower, which pushes the switch circuit transformer to work. The output voltage of the transformer is filtered by the rectifier rectifier filter. After the transformer is started, the feedback circuit feedback voltage is supplied to the control circuit to cut off the startup circuit. At the same time, the control circuit outputs the rectangular wave pulse width to constant the transformer output voltage. The role.
Electromagnetic feedback type, off power supply, switching loss is relatively small, the primary side of the transformer is connected in push-pull form, the voltage voltage of the collector of the power switch tube is twice the input voltage, the high-power converter suitable for low-voltage input, the two-way rectangle with opposite phase The wave drives two power switch tubes to be alternately turned on. The feedback voltage modulates the drive wave pulse width through the control circuit, adjusts the duty ratio, and keeps the output voltage constant. When the load is constant, the output voltage is determined by the following formula: tO drive wave duty Ratio, 0 output voltage vv input voltage switch tube conduction time 101 switch tube off time dead time time transformer primary side turns transformer secondary side turns electromagnetic feedback type switch source consists of pulse width modulator 7494 and corresponding ruler 0 The air ratio control circuit 1 pulse width modulator 494 contains an oscillator, the oscillation frequency is determined by the external resistance core, and can be used as an external voltage control or soft start control, and the other end of the comparator is connected to the output terminal of the error amplifier. The error amplifier is a differential input amplifier. The non-inverting input terminal is connected to the internal voltage of the 1494 reference voltage divider. The inverting input terminal is connected to the voltage divider of the transformer feedback. The output pin sensitive voltage is compared with the sawtooth wave, and the output widened rectangular wave is output. 2, the rectangular wave is divided by a 1 flip-flop, the NAND gate is transformed, the pole tube current is amplified, and the output is switched between the two phases with a dead zone.
Performance characteristics Electromagnetic feedback type switching power supply realizes high-power 0,0 conversion, the power output power can reach more than 200 ash, and the efficiency can reach 70 or more. The working frequency of the power supply is high, and it is 20 volumes and 2 or more. The corresponding filter capacitor is small, and the circuit board is small in size and light in weight.
By using electromagnetic feedback, the pulse width is adjusted to stabilize the voltage, the voltage and load regulation rate are relatively high, a large number of voltage regulators are removed, the cost is reduced, the volume is reduced, and the circuit and the structure of the platform are simplified, and the system is improved. Reliability ensures a small design goal.
The control circuit uses electromagnetic feedback to supply power from the cut-off circuit. The start-up circuit 3 has a large output feedback circuit and a high tube requirement. The tube often works in the limit parameter state, the tube heat is easily damaged, and the reliability is very low.
With the 3 start-up circuit, after the input is powered up, the regulator tube provides a bias voltage for the pole tube, and the pole tube conducts to provide the working voltage for the control circuit. When the transformer works, the feedback circuit feedback voltage raises the pole tube. The emitter voltage is cut to 1 for the control circuit, and the feedback voltage is also used for the control circuit. Pulse width modulation does not need to set a dedicated dry pulse width modulation feedback circuit, which greatly reduces power consumption and improves Reliability.
When the input voltage of the circuit is reversed, the primary winding of the transformer and the power switch tube form an internal short circuit to the input, the starting circuit cannot be started, and the whole converter does not work. The experiment proves that the high current of 15 people does not make the transformer and the minute. The switch tube is damaged, so that it can protect me.
Rectifier mining, full-wave rectification, negative output common winding, the negative terminal only needs to reverse the rectifier tube, not only can balance the output voltage, but also use less than half of the bridge rectifier tube, the power consumption is reduced by half, the output loop The resistance in the middle is also reduced, which is beneficial to the voltage output.
The circuit has a delayed start function, and it is no longer necessary to design a delay switch for systems that need to work asynchronously. Some systems have power supply timing requirements. For example, an inertial measurement system requires a gyro-closed power supply to be delayed by 5 seconds than the motor power supply. If an electromagnetic relay is used to control the switch, the cost is high, the reliability is poor, and the delay time is not easy to adjust. If the time is too short, the gyro in the combination will have a shelling phenomenon due to the competition of the power supply timing. If the delay time is too long, the reaction time of the inertial combination will be lengthened. The delay circuit composed of the resistor scale capacitor 0 and the inverter not only has a simple circuit structure and high reliability, but also has a delay time of ä¸=foot, which can be easily debugged with the whole machine, and only needs to adjust the resistance ruler to obtain the It takes time.
The emitter follower improves the driving waveform, which not only reduces the power consumption of the switching tube, but also prevents the push-pull tube from being turned on at the same time, improving reliability. 105 tube input impedance is very high, the output impedance of the drive circuit must be relatively low, in order to suppress the oscillation component in the drive wave, reduce the rise time and fall time of the drive wave, and make the push wave more regular to adapt to faster switching speed. The power consumption of the switch tube is greatly reduced to prevent its overheating breakdown. Although the output stage of Ding 1494 is a pole tube, its switching time is not conducive to the discharge of the parasitic capacitance of the 05-gate end, and the addition of a stepped emitter follower between the stomach and the 5 tube can greatly drive the waveform. Improvement, 5. The tube source is connected to the inductor, which is an effective application of the zero voltage switching technology. During the turn-on or turn-off of the VMOS transistor, due to the influence of its output parasitic capacitance, the current rises and the voltage drops or the current drops. There is an overlap process in the voltage rise, which causes the power tube to generate a fixed loss. The series inductance and the parasitic capacitance of the switch tube form a series resonance, which effectively suppresses the overlap process and reduces the power consumption of the switch tube.
The experimental results in the switching power supply, the on-resistance determines, the output voltage and loss of the switch, the tube with small on-resistance, the higher the efficiency of turning off the power supply, due to the push-pull method, the cut-off voltage of the switch tube is the input voltage of two Double, considering the derating, the withstand voltage of the switch tube should be about double the input voltage, then the tube with high on-resistance and high withstand voltage should be used, but the tube with high withstand voltage has large on-resistance. At the same time, the gate terminal voltage rises and the on-resistance decreases. Excessive loss of the switching tube will limit the power output of the converter, so it should be considered when selecting the switching tube.
As a rectifying power pole of the power supply, it should have a small forward voltage drop, a small reverse leakage current, and a small reverse recovery time. The forward conduction voltage drop affects the conduction loss of the pole tube until the efficiency of the converter. The reverse recovery time will affect the operating frequency of the switching power supply. Although the Schottky base tube has the above holding point, its reverse cutoff voltage is low. , below 100, the ultra-fast recovery rectifier tube rectification characteristics are worse than the Schottky base tube, but its reverse cut-off voltage is higher, which is an ideal choice. Improper selection of the pole tube will directly affect the output power of the converter. In the electromagnetic feedback type switching power supply, the parallel ultra-fast recovery pole tube rectification is adopted to improve the rectification characteristics.
Electromagnetic feedback type switching power supply can meet the performance requirements of miniaturization and high power. The output voltage is stable and the reliability is high. The output voltage of the converter can be easily adjusted by the resistor to achieve the required value.
The following is the test data of the group ±50V and ±15V output voltage, the input voltage is 27 soil 4V, when the output power is 100, the input voltage adjustment does not change, the load adjustment voltage is less than 3, the ripple is maximum 160, the efficiency Up to 75.
Input Voltage Load Output Voltage Load Output Voltage Load Output Voltage Load Output Voltage Conclusion The application of switching power supply technology in the world is becoming more and more popular and attracts more and more attention. Electromagnetic feedback type switching power supply is a kind of excellent, 70 converter, simple circuit structure, high reliability, low cost, output voltage can be set according to requirements, debugging is also very convenient, its high power and high efficiency can be extended When starting up, etc., it is used in power electronics.
Suizhou simi intelligent technology development co., LTD , https://www.msmsmart.com