Ohm’s Law Appartus

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

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. The kit consists of : 1. Baseboard, plastic, with spring terminals and three battery holders. (1) 2. Batteries. (3) 3. Lamps 1.25 V MES. (10) 4. Lamp holders mounted on PCB connectors. (6) 5. Plain connector PCBs. (10) 6. Wire wound potentiometer with crocodile clip connections. (1) 7. Silicon diode. (1) 8. Resistor 3.9 ohm 2.5 W (1) 9. Pair Leads, red, with crocodile clip at each end. (1) 10. Pair Leads, black, with crocodile clip at each end (1) 11. Pair Leads, yellow, with crocodile clips at each end. (1) 12. Switches mounted on PCB. connectors (2) 13. PVC rod 15 cm long (1) 14. Soft iron nails, 5 cm long (2) 15. Bare copper wire, swg 20 (2 m) 16. Bare eureka wire, swg 34 (2 m) 17. Plastic covered copper wire (2 m) 18. Electrode support (1) 19. Pencil lead electrodes (10) 20. Sheet copper foil, 150 mm square (1) 21. Pack Steel wool (1) 22. Instruction manual in English. (1)

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

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.