what is lost in power dissipation?

Thread Starter


Joined May 24, 2012
Yes , I know - Power is lost in power disipation - but how does this affect a circuit?
would there be a lost in current? voltage? both?

I'm a real n00b with this stuff and it's taking time to wrap my head around it :(




Joined Aug 16, 2010
Power dissipation generates heat in your circuit and may or may not be a problem depending on the circuit.

For example, you see a lot of posts here that ask "why is my voltage regulator getting hot?". Its because power is dissipated in the regulator due to the voltage across it and the current through it, P = V x I.


Joined Sep 20, 2005
If you think about a two-terminal device like reisitor or diode, the curent into one terminal has to be the same like the current going out of the other terminal, hence the current stays the same. If the device had no voltage drop, there would be no power lost like in superconductors.
So when something dissipates power there is a voltage drop somewhere and at the same time there is current flowing through that.


Joined Oct 22, 2008
Power may be lost from the circuit's point of view but it's never really lost; it always goes somewhere - heat, light, sound, motion, chemical changes as when charging a battery.

Current and voltage are not really power themselves; they are more like carriers of power. They carry power from a source like a generator or battery to a load, which is another name for a destination of power.