Recognizing Frequency Board

- Jan 27, 2018-

With the high-frequency driver protection and driver board, the user To test normal static (without mains case) the output waveform, note the following points:

1, if the power transistor IGBT or MOSFET is connected in the circuit, and the coupled drive power and the PWM input signal, the output on the oscilloscope can see the corresponding output signal.

2, if the power tube is not connected, just doing an output test, then you must be connected to the power tube collector and emitter (or drain and source) be two points short job. Because if the collector or drain vacant, then the drive or the drive plate will assume state power tube is starting an internal short circuit protection mechanisms, then see will be the protection of the driver output signal waveform, whether or cycle waveform shape and input of the PWM signal is completely different. IGBT in the application to solve the main problem is how to overcurrent, short circuit and overvoltage in the case of the IGBT to implement more complete protection. Overcurrent fault generally require a slightly longer time to make the power overheating, so its protection by the main control board to resolve. Overvoltage shutdown generally occurs in the IGBT, the larger di / dt is generated in the parasitic inductance of the high voltage, which requires a snubber circuit to suppress, or appropriate to reduce the rate of turn-off. Instantaneous short-circuit fault occurs it will have a great currents, will soon damage the IGBT, the main control panel overcurrent protection no time, it must be the driving circuit or drive immediately to protect them.

Therefore, the drive circuit protection design is perfect, is essential for the safe operation of the power supply. Get a driver circuit, test it before using short-circuit protection function is perfect, it is necessary.