On Sep 19, 12:23*am, Square Peg wrote:
Most coffee mug warmers are under-powered. One reviewer on Amazon said
that they were restricted to about 24 watts by law.

This one

http://www.amazon.com/Bunn-BCW-Warme.../B00023WAS0/re...

is made for warming the whole coffee pot. It says it's 120V/15amp.
Several of the reviews say that they use it for a single cup, but it
keeps it too hot. It only has on/off -- no temperature control.

Can I put it on a 300 watt dimmer switch like this?

http://www.amazon.com/Lutron-Electro...-300H-WH/dp/B0...

If not, is there a way to ramp the the power down as an external
thermostat?

It will work but if the warmer pulls more than the dimmer spec it will
burn out the dimmer, 15a is an expensive dimmer,Ive never seen more
than 1000w for 50$