Hair dryer fuse too low for spec power?

So I'm tearing down this hair dryer for a school project where I need to make it have variable heat and variable motor speed which can be controlled through an Arduino. I'm currently looking at where I would need to replace the switch and resistor with the rheostat, but just after the switch and resistor, there's an SF169E thermal fuse that is only rated for 10 amps. However, the hairdryer is supposed to be rated for 1875 watts. 10 amps and 125 volts translates to 1250 watts, so where would the other supposedly 625 watts be going? Thanks for your help!

by lopez8596
May 20, 2020

Here is a picture of the diagram I made, however all of the resistances are made up.

by lopez8596
May 20, 2020

With the numbers you've given the discrepancy you've noted is a mystery. Is there any chance the number you've interpreted as 10 is actually 15 or 16? I expect the text on the fuse is pretty small and a 0 and 5 or 6 could look similar. Beyond this you have the chance to make an interesting project. 125vac through an opto-isolator to the heater, generate a low frequency pwm with the Arduino to control ac on/off to the heater via the opto-isolator. Control the motor with an Arduino pwm output via an opto-isolator on the dc side of the motor rectifier. The opto-isolators are necessary to keep the high voltage ac out of the Arduino

by Foxx
May 22, 2020

Oh Yeah--You,ll need a MOSFET for the actual on/off control

by Foxx
May 23, 2020

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