Demonstraton Electric Bell

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

The large size of this battery operated apparatus allows students to better understand the operation of this basic circuit. Works on 9 V Battery. Includes Instructions. On wooden stand.

Description

The dynamo model is mounted on a base with a driving wheel. Output is through 4 mm sockets and a low voltage bulb is also provided as a simple output indicator.

Description

The motor consists of a two pole armature mounted between the ends of two bar magnets. The armature has a two section commutator and a pair of slip-rings on its shaft and is so constructed that the wire cannot slip off the iron core. The upper bearing and brushes for the commutator are mounted on a strong upright. Separate brushes are provided for the commutator and for slip rings and each are connected to a terminal. The magnets are held in position by thumb screws.