My question is :
Is a 68 ohm 1/8 watt resistor the same as a 68 ohm 1/4 watt or 68 ohm
1/2 watt.
My led circuit calls for a 68 ohm 1/8 watt, can I use any resistor that is rated 68 ohms.
Thanks Dennis
Resistor question
Nov 03, 2006
3 Replies
1/2 watt.
They all have the same resistance.
The /18th watt will reach its rated operating temperature with 43 mA through it (2.9 volts across it), the 1/4 watt with 62 mA through it (4.2 volts across it), and the 1/2 watt with 88 mA through it (6 volts across it).
As long as the current through your resistor is less than its rated current, it will work. I like to derate resistors to half their rated wattage for long life and low thermal drift.
Thanks John. You electronics freaks are a God send. It is so great to have a place that people freely share knowlege and ideas. I share when I can.
Well, thanks for this - it's nice to be praised, too. :-)
Cheers! Rich
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required