The electro magnet makes no pretense of being anything else but a 5 ins nail wrapped in cable. It can however produce a reasonably strong magnetic field using a 1.5V cell, strong enough to pick up small washers or nails. To conserve the life of the batteries or to prevent too high a voltage being applied for too long then it is suggested that a push switch is incorporated into the circuit.
This equipment is designed to sit on top of an overhead projector. When a current is applied for a brief period the compass needles are seen to form a circular pattern around the conductor. The compasses, which have glass on both sides, are not included in the price but can be purchased separately – see price list.
Two Magnadure magnets (not included) are attached to the bracket to produce the magnetic field. The bracket can be swiveled round to reverse the direction of the magnetic field and hence the direction of movement of the runner.
