Resistance Coils

Enables students to investigate nature and properties of electricity by using simple circuits which are easily constructed on a base board. The connector system uses P.C.B. strips with cut-out sections whose ends can easily be inserted in spring terminals, ensuring low contact resistance and ease of connection.

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 12VDC 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.