Need some electrical help

Ok all of you electrical guru's out there, I know that you can use a resistor to make a dummy electrical load, but I have never done this before.

So if any body could help me figure out what size resistor I need to replace a 12v load that has 18-20 ohm resistance.

Just use a light bulb. It's just a resistor that diplaces its heat via light.

How much resistance do you need and why.

The Big Spank Daddy said:

Just use a light bulb. It's just a resistor that diplaces its heat via light.

How much resistance do you need and why.

Click to expand...

I thought about using a light bulb, but I would really like to use a resistor
instead.

Resistors have lots of things you need to be aware of.
1-value
2-% tolerance from value
3-POWER RATING
4-composition[material it's made of
The circuit you want to "fool"
1-POWER FLOWING IN CIRCUIT
2-CURRENT FLOWING IN CIRCUIT
Now, using basic formula of P=IV[power equals current times voltage, figure out maximum current flowing in circuit. Take this answer and insert in formula R=P/IxI[resistance equals power divided by [current times current]. The answer is the VALUE OF RESISTOR you need. Back to the original value of POWER, that is the minimum power rating of the resistor. Pick next higher value. If size is a factor, use a WIRE-WOUND resistor[smaller for same power rating]
Hope this helps,
Wally, bench electronics technician
PS: High power numbers mean lots of HEAT---AKA meltability factor
OR......................
e-mail me the power number and i'll send you the answer