More information about resistors would be helpful.

Thread Starter


Joined Feb 2, 2005
There are formulas that tell a person how long it takes until a resistor will burn out with applied power. Could someone help put that information into this website?


Joined Feb 20, 2005
Power capacity of resisitors

Power capacity for the resistor is indicated in Watts.

For example; Take a 100 ohm, 10watts resistor,

there is a simple formulae for power in electricity,

Power P = voltage x current,
but voltage = current x resistance
Hence Power is also = current x current xresistance
The units for Power in watts,voltage in volts and current in amps.
Here for the resistor 10 watts , the value of the resistor 100 ohm is the limiting factor for the current flowing in the resistor.(and also 10Volts is applied acrossthe resistor)
The current flowing = voltage/resistance =10/100 = 0.1 amp only,but
Maximum current allowable through the resistor is = power/voltage = 10/10=1.0amp
If it exceeds 1.0 amp current the resistor starts safe.


Joined Apr 20, 2004

You may have a fun time coming up with a generallized formula. The time to fry a phenolic-over-carbon resistor is going to be different than for a wirewould unit of about the same dissipation. And I suspect that trimmed film on ceramic will be a bit different than the other two.

I always thought the trick was to keep from burning up your resistors.