Platinum Resistance Thermometer

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.

Description

Apparatus is designed primarily for demonstration of the basic principles of transformers. It consists of a laminated U-core with laminated I-core, both with 32 x 25 mm cross section to form a closed core of size 102 x 127 mm. Heavy aluminium alloy stand with removable clamping rods, 2 pole pieces, each 65 x 30 x 25 mm with one end cone shaped, to accept support rod and shading ring. Poles also have a hole drilled through lengthwise to take a light beam.
300 turns
600 turns
1200 turns
3600 turns
12000 turns

Description

Investigate the working principle of circuit breaker type fuse with this demonstration model. The apparatus is built on a robust plastic base and includes resistive loads to simulate external wiring circuits. Applications of the thermal response of bimetal strips and also electromagnetism (movement from a solenoid) are clearly demonstrated in this model. When a 12 V DC supply is connected (not supplied) the LED lights to show that current is flowing in the external circuit and the bi-metal strip can be seen to bend as its heater coil raises the temperature. After a few minutes the bending is sufficient to trip the mechanism and the current path is broken. At any current selection a short circuit situation can be initiated by pressing the red button and this produces an immediate response from the solenoid to disconnect the supply.

Description

For Westminster Electromagnetic Kit giving 1 V full wave rectified DC and 1 V / 2 V AC outputs at 8 A max. The circuit diagram is printed on the top panel which also carries mains switch, light indicator and output sockets for DC and AC With 1.5 meter mains detachable cable.