Comment on What is negative voltage?
JelleWho@lemmy.world 4 days agoThis explanation is good indeed.
Sometimes you design a circuit where the main chip runs on +3.3V reference to the chips ground at 0V, but somewhere in the proces you end up with an extension board that wants 5V below the ground. For easy of use we just call this -5V instead of renaming everything to 0, 5, and 8,5V. Renaming also has the drawback that I like to measure everything reffering to the ground of the main chip. So I personally just don’t rename and keep my reference there.
CetaceanNeeded@lemmy.world 4 days ago
Just so I understand.
In your example, let’s say we have a power supply that distributes 5v and 8.5v.
The extension board is easy, we just hook it up from 5v to 0v.
For the 3.3v chip, are we wiring it between 8.5v and 5v? So it only sees a 3.3v voltage difference?
JelleWho@lemmy.world 3 days ago
Correct.
A good ‘at home’ example is your computer power supply
TBi@lemmy.world 3 days ago
Yes. That will give you a 3.5v difference.