I have this setup on the bench and I just wanted to compare computed readings from calculated ones and I am confused. First of all I am not a professional, just a guy trying to learn electronics. I have a 40w heater in series with a fan. The total current draw of both is 164mA. I measured the resistance of the heater to be 320 ohms and the fan to be 185 ohms. Mains voltage is 117v. Here is where I get confused:
Calculated heater voltage: 164mA x 320 ohms = 52V
Calculated fan voltage: 164mA x185 ohms = 30V so why do I get a measured reading of 65V at the fan when the reading of 52V at the heater seems to workout?
The only thing I can think of is that my reading for resistance is wrong. Does the resistance of an electric fan motor change when it runs?
Thanks for your responses.
PV
Calculated heater voltage: 164mA x 320 ohms = 52V
Calculated fan voltage: 164mA x185 ohms = 30V so why do I get a measured reading of 65V at the fan when the reading of 52V at the heater seems to workout?
The only thing I can think of is that my reading for resistance is wrong. Does the resistance of an electric fan motor change when it runs?
Thanks for your responses.
PV