Regarding 8050, the problem of small voltage controlling large voltage.

tongshaoqiang

Regarding 8050, the problem of small voltage controlling large voltage. [Copy link]

Use the MCU IO output level (0-3.3) to control the on and off of 8050, thereby controlling the presence or absence of 12v and the power supply of the device. Now the problem is that it can't be turned off. I think the state of the transistor is not adjusted correctly (Rc resistance). Please give me some guidance.

maychang

Saw your other post.

8050 is an NPN tube, and the PNP tube 8550 is used in the electrical schematic diagram in that post.

Using 0~3.3V to control the NPN tube will not cause the problem of "not being able to turn off".

Make sure the polarity of the tube is clear first.

wangerxian

There are also problems with the parameters of components in the circuit.

qwqwqw2088

Sometimes the tube is also related to the load, such as the interference of the inductive load of the motor, and the poor anti-interference ability of the circuit.

Need to optimize circuit parameters

tongshaoqiang

maychang posted on 2022-5-25 19:30 I saw your other post. 8050 is an NPN tube, and you used a PNP tube 8550 in the electrical schematic diagram of that post. Using 0~3.3V to control the NPN tube will not...

Thank you maychang for your guidance. The network was a bit slow when I was posting, so I thought I didn’t post successfully. I sent too much. Please refer to the other post.

bigbat

You should first understand the MOS tube and the triode, and then talk about your problem. Tips are as follows:

MOS: voltage control

Transistor: Current control, requires current to reach the saturation state of the transistor.

chunyang

It is easier to judge if a specific circuit is given.