Electricity
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Electricity
Circuit Breaker Demonstration
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.PH50136C -
Electricity
Earth, Neutral and Live Board Demonstration
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 meters of fuse wire and full instructions. A 12V D.C. power supply is required. Connections are made via 4mm shrouded sockets.PH50136E -
Electricity
Worcester Circuit Board
Enables students to investigate nature and properties of electricity by using simple circuits which are easily constructed on a baseboard. 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.
- 3 Batteries.
- 10 Lamps 1.25 V M.E.S.
- 6 Lamp holders mounted on P.C.B. connectors.
- 10 Plain connector P.C.Bs.
- 1 Wire wound potentiometer with crocodile clip connections.
- 1 Silicon diode.
- 1 Resistor 3.9 ohm 2.5 W.
- 1 pair Leads, red, with crocodile clip at each end.
- 1 pair Leads, black, with crocodile clip at each end.
- 1 pair Leads, yellow, with crocodile clips at each end.
- 2 Switches mounted on P.C.B. connectors.
- 1 PVC rod 15 cm long.
- 2 Soft iron nails, 5 cm long.
- 2m Bare copper wire, swg 20.
- 2m Bare eureka wire, swg 34.
- 2m Plastic covered copper wire.
- 1 Electrode support.
- 10 Pencil lead electrodes.
- 1 Sheet copper foil, 150 mm square.
- 1 Pack Steel wool.
- 1 Instruction manual in English.
PH50152 -
Electricity
Westminister Electromagnetic Kit
A very effective and motivating learning aid in elementary electromagnetism. Consists of 8 anisotropic alloy magnets, 8 ceramic ferrite magnets, 4 steel magnet yokes, 6 plotting compasses, 4 hardboard formers to take compasses, 1 bottle iron filings 250 gm, 4 dispensers for iron filings, 4 double C-cores, 4 clips for C cores, 4 Aluminium rings, 4 Aluminium split rings, 4 armatures with axle tubes, 4 Aluminium axle rods, 8 split pins, 16 rivets, 4 formers for coils, 4 reels cello tape, 4 reels copper wire, 4 sheets white pasteboard, 4 plain postcards, 4 reels white cotton thread, 1 length latex rubber tubing, 4 each resistors 100 ohms and 10 ohms, 4 support bases, 10 M.E.S bulbs, 8 MES bulb holders,1 wood clamp and 1 wooden block. With instructions.
PH50160 -
Electricity
Power Supply, 2V
For Westminster Electromagnetic Kit giving 1 V full wave rectified D.C. and 1 and 2V.A.C. outputs at 8A max. The circuit diagram is printed on the top panel which also carries mains switch, light indicator and output sockets for D.C. and A.C. With 1.5-meter mains detachable cable.
PH50163
