The Helmholtz Coils are precision made and 400 turns of wire are wound on a heat resistant polycarbonate former with feet to rest on the table and to locate over a standard 1/2 metre rule. They are normally used in pairs. Each coil has 4mm spin free IEC terminals and their distance apart is adjusted over the wooden rule supplied. The maximum current in the coil is 1A to avoid overheating. Resistance of each coil is about 20ohm when cold and about 25ohm when warm. Direction of current is marked on each coil. Helmholtz coils are normally used for field strength study.

150mm average winding diam. 400 turns