QT PY 5V input diode requirement
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- yzfoot
- Posts: 79
- Joined: Wed Dec 08, 2021 6:02 pm
QT PY 5V input diode requirement
Pinout blurb says it's important to place a diode between external power and 5V input pin. What is the purpose of this ? Backfeed protector ? Voltage drop ? Other ?
- rpiloverbd
- Posts: 198
- Joined: Mon Nov 29, 2021 8:13 am
Re: QT PY 5V input diode requirement
To protect the board from sudden spikes maybe?
- dastels
- Posts: 15831
- Joined: Tue Oct 20, 2015 3:22 pm
Re: QT PY 5V input diode requirement
The reason for the diode is to protect against the problem of having an external supply connected when you plug in USB. There's a diode onboard between the 5v line on the USB connector and the 5v pin. By putting one on an external supply you guarantee that only one is providing 5v to the board: whichever is higher.
Dave
Dave
- yzfoot
- Posts: 79
- Joined: Wed Dec 08, 2021 6:02 pm
Re: QT PY 5V input diode requirement
Dave
Thank you. That explanation of why would be welcomed by many along with the statement that the diode is needed.
Thank you. That explanation of why would be welcomed by many along with the statement that the diode is needed.
Please be positive and constructive with your questions and comments.