Resister Wattage

greaserrock · Post by **greaserrock** » 22 Jan 2012, 21:08

Hi,

I am trying to build the hemmo/christian’s ultra simple bazz fuss circuit as suggested by Beavis Audio as a starter project. It asks for a 10k 1/4watt resister. On a whim I had previously bought some 10k 1/2 watt resisters. Can I use the 1/2 watt resisters? Are they like capacitors in that a higher amount than recommended is ok but a lower amount is not?

TubeDude22 · Post by **TubeDude22** » 22 Jan 2012, 21:50

Yes, it is safe to use 1/2 watt in place of 1/4 watt resistors in the circuit.

greaserrock · Post by **greaserrock** » 23 Jan 2012, 00:04

Thank you! Much appreciated TubeDude22.

digitalzombie · Post by **digitalzombie** » 11 Feb 2012, 01:48

What's the difference between using a 1/4 watt and a 1/2 watt?

PokeyPete · Post by **PokeyPete** » 11 Feb 2012, 15:23

digitalzombie wrote:What's the difference between using a 1/4 watt and a 1/2 watt?

1/2 watt resistors are bigger, usually!

Actually, a circuit board designed for 1/8 watt or 1/4 watt resistors may not have room for a 1/2 watt resistor.

But to better answer your question.....if current is flowing through a resistor, then there is a voltage drop across
the resistor. That voltage drop multiplied by the current flowing through the resistor gives the wattage needed
by the resistor. The power in watts is given by the formula P=IE....P in watts, I in amps, E in volts.

For example if you used the formula to calculate the power rating of a particular resistor and found that it needed
to be .450 watts.....this would require at least a 1/2 watt resistor (probably really a 1 watt would be better). If
you used a 1/4 watt resistor instead, it would probably explode soon after power up!