Electric Bell

Description

A simple kit for students to gain insight into field poles, armatures and switches, one mounting base, two coils of insulated wire , field pole, mounting bracket, two armature halves, one piece of insulating tubing, motor shaft, two commutator insulators, two bronze wire brushes, two shaft supports, four paper fasteners, a AA battery holder and 6 each of screws and nuts. Requires one AA battery, not supplied, with assembly instructions.

Description

This apparatus is an effective demonstration of how the earth wire and fuse act together to protect both the user and the appliance. When the appliance is connected correctly and the LEDs in the appliance will illuminate to show the appliance is working. A fault is then demonstrated by swapping the live wire from inside the appliance to the case to show either the fuse melts (protecting the user and appliance) or in the case of no earth wire, the LEDs illuminate to indicate the passage of current through the person to ground. The fuse is easily visible and can be seen to ‘blow’ when a fault occurs.The unit is supplied with 10 m of fuse wire and full instructions. A 12 V DC power supply is required. Connections are made via 4 mm shrouded sockets.

Description

A simple form of D.C. motor with 2 pole armature wound with insulated copper wire and a permanent magnetic field provided by a removable bar magnet with a commutator and phosphor bronze brushes connected to 4 mm sockets, open construction, all parts visible.

Description

Each wound on a rectangular insulated bobbin, connections by 4 mm sockets spaced at 19 mm