Uncle Bambi
Funky Tut
I have a receiver with a burnt out dial display bulb. The bulb is rated at 28v/100ma, although actual measured voltage across the bulb is 24v
Since I do not have a 24v bulb but I do have a 12v one, I thought I'd try putting a resistor in series with the 12v bulb in order to drop the voltage and use the 12v bulb. I did this with a 50 Ohm 5w resistor and it worked........ BUT the resistor gets too hot to touch in a matter of less than a minute. I tried as low as a 25 Ohm 5w (too bright), and a 100Ohm 5w (too dim). In all cases, the resistor gets too hot to touch inside of a minute.
What's going on here? What simple thing am I missing?
Since I do not have a 24v bulb but I do have a 12v one, I thought I'd try putting a resistor in series with the 12v bulb in order to drop the voltage and use the 12v bulb. I did this with a 50 Ohm 5w resistor and it worked........ BUT the resistor gets too hot to touch in a matter of less than a minute. I tried as low as a 25 Ohm 5w (too bright), and a 100Ohm 5w (too dim). In all cases, the resistor gets too hot to touch inside of a minute.
What's going on here? What simple thing am I missing?