I have long wanted to make a small and comfortable, inconspicuous heat source that could use both at home and on the bus or in the office. It should be operated from any source of energy, consume very little power and long run on batteries. It should have a heat regulation. It should be very simple to make and very inexpensive cost...The result is a carbon heated belt.
For my waist took 0.9 meter (3 foot) of carbon tape 44 mm from www.carbonheater.us, a small strips of black and white fabric, one button, one meter ultra flexible cable with silicone insulation, female plug 5.5 mm with wire. The desired temperature can be determined from the table.
New! Now it works with RF remote dimmer!
I cut four strips 10 cm wide of some inexpensive white fabric. Three stripes stitched together. Then sewed them with carbon tape.
Top will be sewed with the remaining fourth strip of fabric. The result will be a sandwich: three layers of fabric + carbon tape + one layer of fabric. The meaning of this is that I can put the belt on one side, if I'm cold or the other, if not very cold.
Know from experience that a carbon tape will last for many years, but a bad wire may break off in a month. I recommend using ultra flexible wire with silicone insulation. For example AWG18 150 strands x 0.07 mm.
You should sew some contacts to the carbon tape. Very convenient to take the wire mesh of any video cable. This mesh will be very good as a contact.
Such contact is soft and can resist to repeated bending.
Solder the wire to the edge of the mesh.
Top sewed the remaining fourth strip of white fabric.
Button glued with a hot glue stick.