Solenoid valve drive

tangwei8802429

Solenoid valve drive [Copy link]

Can I remove the transistor?

tangwei8802429

Is it possible that current will flow to the gate of MOS and break down the microcontroller?

chunyang

It is possible to remove the transistor, but it requires that the previous stage driving voltage meets the turn-on voltage requirement of the MOS tube, and the driving logic also becomes highly effective.

chunyang

tangwei8802429 posted on 2018-2-25 23:55 Could it be that MOS will have current flowing to the gate and breaking down the microcontroller?

Of course it has nothing to do with this.

395qav

You can remove the transistor, but you have to calculate the power consumption. If the current is high, it may burn out within 1 second. In addition, when the solenoid valve is closed, it will generate a double voltage reverse voltage. If the withstand voltage is not high enough, it will also collapse quickly.

maychang

When removing the transistor, two points need to be considered: first, the direction of the drive signal (P21) changes to be high level valid; second, whether the P21 signal level meets the MOS tube input amplitude requirement.

qwqwqw2088

395qav posted on 2018-2-26 07:14 The transistor can be removed, but the power consumption must be calculated. If the current is relatively high, it may burn through within 1 second. In addition, the closing of the solenoid valve will generate a reverse voltage doubler...

"If the withstand voltage is not high enough, it will also collapse quickly." The collapse of the solenoid valve has little to do with the previous transistor. The designer of this transistor should still consider protecting the MOS and the microcontroller.

szc5b

Explain the MOS model to see if the driving voltage meets the requirements. For this kind of occasion where the switching frequency requirements are not high, IO direct drive low-voltage MOS is also possible, but it is not very reliable. When the MOS burns, the IO will also burn. Add a transistor to play a protective role. When the frequency is high, there are requirements for the driving current. Direct drive MOS is likely to burn out the IO.

tangwei8802429

Thanks for your answers. I know what's going on.

3211181596

Can a trigger pulse from P21 control the switch of the solenoid valve?

爷乐子

3211181596 Published on 2018-10-23 22:06 Can a trigger pulse from P21 control the switch of the solenoid valve?

Give a low level