Electric Bell

Description

Mounted on panel, large size parts and visible wiring. Operates on 4 – 6 V DC

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

Comprising 1 welding coil of 5 turns on former with insulated handle and short-circuiting pins,1 annular melting trough with insulated handle to show heating by induction,1 jumping ring which is thrown clear when primary current is started and a floating ring which remains freely suspended when primary current is flowing.