The heatable coffee mug is designed to heat and reheat your coffee and any other hot beverage on the go. It uses a 12 V adapter and is merely heated by six 47 ohm resistors. It is a cheap product to make and only takes about 2 days to construct (since epoxy takes about 20 hours to dry and will be used twice).
-one wire stripper
-one 12 V cellphone adapter
-one metal cup
- six 47 ohm resistors
- plastic water bottle
- soldering iron
- one bimetallic switch
The Heatable Coffee mug will include six 47-ohm resistors, the bimetallic switch, and the 12 V adapter. First tie the ends of the resistors together, making sure they are perfectly aligned. These will be in a parallel circuit so as to use more current, thus generating more heat to boil the water in the cup. Make sure the head piece of the adapter wire has been cut off and the two wires have been separated.
Cut off a medium-length piece of the adapter wire and solder it to one end of it to the resistor; solder the other end to one prong of bimetallic switch. Take the other wire (which is still attatched to the adapter) and solder it to the other prong of the bimettalic switch.
Take a styrofoam cup and mix the two components of the epoxy together with a straw. Glue the resistors to the side of the stainless steel cup; glue the bimetallic switch to the bottom of the cup. Allow the epoxy sit for 20 hours; DO NOT touch the cup.
Cut the "ribbed" part off of the bottle with an electric saw; the cup will be inserted into the bottle.
Drill a hole where the resistors match up to the cup; make sure the hole is a little bigger than the wire so it's easier to slide it through.
Since there's no way to fit the adapter into the hole, you need to cut the wire midway. Separate the two wires, strip them and solder them back together after the wire that's soldered to the resistors has been put through the hole.
Epoxy the ribbed piece back to the plastic cup; wait 20 hours for it to be perfectly sealed.
Congratulations! You now have a heatable coffee mug to heat your coffee, tea, etc on the go! And since it's got a plastic layer around it, you won't have to worry about burning your hand!