1
\$\begingroup\$

I am trying to make a simple BMS by referring to the circuit on this site.

enter image description here

I want to know why the digital outputs of the Arduino are not directly connected to the gate of the MOSFET, but are connected through an NPN transistor and a PNP transistor and why the B3 11V1 battery connected to the PNP transistor's emitter.

\$\endgroup\$
2
  • 2
    \$\begingroup\$ Think of them as level translators. \$\endgroup\$
    – Rohat Kılıç
    Commented Nov 8, 2022 at 16:31
  • 4
    \$\begingroup\$ FYI, this is a terrible BMS. Huge idle current, ridiculously oversized transistors, and, who knows what the MCU is doing, I'm sure there's bugs on that side too. \$\endgroup\$
    – Tim Williams
    Commented Nov 8, 2022 at 17:16

1 Answer 1

Reset to default
3
\$\begingroup\$

They are level translators. The MCU looks to be a 5V device. The designer is wanting to drive the gate of the FET with 11V. So the transistors are controlling the 11V with a 5V signal.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.