A heat circuit, such as the element you find in an electric heater, is effectively a short circuit between the positive wire and the negative wire. However, other components are fitted in an electric heater that you use at home to ensure that fuses don’t blow and the wire doesn’t melt. You can make your own heat circuit, as an educational project with your kids. It perfectly safe, as it’s powered by batteries, and it’s fun to make. It teaches kids about the basics of electrical circuits.
Wind about 4 inches of bare AWG 18-gauge wire loosely around a pencil. You want it to look like a coil or spring. This is the heat element. Ensure you have about 1 inch loose at each end of the coil.
Cut two 6-inch strips of plastic-coated single-core AWG 14-gauge wire with a knife. Remove 1/4 inch off one end of each wire and 1/2 inch off the opposite ends using wire strippers.
Attach the 1/4-inch end of one of the wire strips to the “-” terminal on the battery. Use a strip of electrical tape to hold the wire in place.
Twist the opposite end of the wire that’s attached to the battery onto the one of the loose ends of wire that’s coiled around the pencil. Twist the 1/2-inch end of wire on the second strip onto the opposite end of the wire coiled around the pencil.
Slide the pencil out from the coil of wire. Do this carefully so you don’t change the shape of the coil.
Put the opposite end of the second wire that’s attached to the coil onto the “+” terminal on the battery. Use your fingers to hold the wire on the terminal. Look at the coil of wire; it glows red and gives off heat, because you have made a heating circuit caused by a short circuit. Remove the wire from the battery and let the wire cool down.
This project is perfectly safe using a battery. However, the bare wire coil gets very hot and will burn you if you touch it.