Do Diodes waste power?

Question

Is there significant power loss in a diode?

Answer 1

The power that ANY electrical component wastes(as heat), is the voltage drop across it (Potential difference) multiplied by the current flowing through it.

If the diode is forward biased there's a small voltage drop (often 0.5V) If it's flowing 1Amp them that 0.5W power.

---

by re-arranging and substitution...

PD[V]=I[A]R[ohm]

R= PD/I

heat[W]= I^2 * R

heat = I * PD

---

Billrus is right in that at high frequencies the losses can be greater

Answer 2

A small amount, the forward drop, 0.6-0.7 volts multiplied by the average forward current.

At higher frequencies, this can go up as the device capacitances come into play.

.

Answer 3

The forward voltage drop across a diode is about 0.6V DC to about 0.4V DC for the smaller to the larger diodes. If you have a  higher voltage application like a high frequency generator I use to work on you need to put the diodes in series in which case the collective Volt drop becomes fairly large.

Also if you feel diodes on low voltage circuit they heat up and therefore according to the law of conservation of energy they are wasting power in heat loss.

Take you transistor filled CPU for instance it wastes some power in heat as well. If you take the benefits of diodes and transistors and their usefulness, the power loss is a minor problem and not enough to worry about.

You will however take in account the voltage drop in design.