Use about 3.3v, about 30Khz, and a PWM wave input with a duty ratio of about 0.7 to control the electromagnet current through the drive circuit and the chopper circuit, but the current keeps changing, and the voltage output from the HO pin of the drive circuit is always The increase is because there is a problem with the circuit principle or the component parameters are wrong. After finishing the design, urgently, please help, thank you!
Dagan 发表于 November 20, 2020
Did the host add freewheeling diodes to both ends of the electromagnet?
Bibi 发表于 November 20, 2020
When the two MOSFETs are turned off, the two diodes D5 and D7 are used as freewheeling diodes to power the electromagnet. Is my understanding correct?
Dagan 发表于 November 20, 2020
The negative pole of the DC power supply you use is not grounded, so can the measurement be accurate?
Bibi 发表于 November 20, 2020
Under normal circumstances, is the current on the load in the middle of the H-bridge chopper circuit constant? Is the voltage of the load a PWM waveform or is it a constant voltage?
Dagan 发表于 November 20, 2020
This problem has not been specifically tested, if the frequency is high, it should be approximately constant.