Resistance

High quality wire-wound controls, ideal for loudspeaker volume controls, miniature motor speed controllers, etc. Power rating: 5W; Resistance tolerance: ±20%; Spindle rotation: 300° ±5°; Max. operating voltage: 120V; Breakdown voltage: 200V. Body Dimensions (Dia. x D): 24 x 11mm. Spindle Dimensions (L x Dia.): 6.5 x 6 mm.

Rheostats ideal for school use. Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled die-cast end stands and 4 mm socket terminals. Dimensions (Dia.): 43 mm.

Rheostats ideal for school use. Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled die-cast end stands and 4 mm socket terminals. Dimensions (Dia.): 43 mm.

Rheostats ideal for school use. Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled die-cast end stands and 4 mm socket terminals. Dimensions (Dia.): 43 mm.

Rheostats ideal for school use. Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled die-cast end stands and 4 mm socket terminals. Dimensions (Dia.): 43 mm.

Rheostats ideal for school use. Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled die-cast end stands and 4 mm socket terminals. Dimensions (Dia.): 43 mm.

Rheostats ideal for school use. Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled die-cast end stands and 4 mm socket terminals. Dimensions (Dia.): 43 mm.

Rheostats ideal for school use. Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled die-cast end stands and 4 mm socket terminals. Dimensions (Dia.): 43 mm.

Rheostats ideal for school use. Consisting of heavily oxidised resistance wire wound upon vitreous enamelled steel tube and locked into place with ceramic cement, multi-leaf phosphor bronze heavy duty sliding contact on nickel plated rod. Robust enamelled die-cast end stands and 4 mm socket terminals. Dimensions (Dia.): 43 mm.

Slide wire pattern with four gaps for known and unknown resistors. A straight resistance wire stretched along metric scale mounted on wooden base. Wire can be easily replaced if damaged or broken. Complete with jockey. All connections are low resistance and via standard 4 mm sockets. Length: 1.5 m.

Slide wire pattern mounted on rigid anodized aluminium base fitted with a metric scale with two equal lengths of constantan wire running across their length. Connection to the resistance wires is made via 4 mm sockets. Resistance wires located along the meter rules, giving total length of 2 metres. Complete with knife jockey. Resistance of wire approx 2 Ω/m.

Jockey for Potentiometer

A four decade resistance box covering to 9999Ω in 1Ω steps. Plastic enclosure box with resistance values 5% tolerance. Dimensions (L x W x H): 165 x 80 x 50 mm.

This apparatus provides the basis for student investigations into resistance. Four wires, 500 mm long mounted on an acrylic base and connected via 4 mm sockets. The wires are all Nichrome with diameters of 1.0, 0.8, 0.63 and 0.4 mm giving resistances in the range 0.4 to ohms. A graduated mm scale is included allowing resistance length and resistance This apparatus provides the basis for student investigations into resistance. diameter investigations to be easily covered. Dimensions (L): 500mm.

Mini substitution unit using a single rotary switch to select from twelve values all at 5% 0.5 W. Values in are 100, 330, 470, 680, 1k, 3.3k, 4.7k, 6.8k, 10k, 33k, 47k and 100k. Connections via 4 mm sockets.

A decade resistance substitution box ideally suited for school or college use. The box will simulate resistances from to 999,999 Ω in 1 Ω steps. The value selected is clearly indicated on the dials.

This apparatus contains an NTC bead thermistor with nominal resistance of 4.7 kΩ in a glass tube with electrical connection made by means of 4 mm sockets. Students from KS3 to Post-16 can carry out practical investigations into the thermistor characteristics. Full instructions and specimen results included. Dimensions (L): 220 mm.

Conducting putty is a useful aid to teaching resistivity and the relationship between length and cross-sectional area on resistance. A cylinder 60 mm long and 20 mm in diameter has a resistance of approximately 20 Ω. Can readily be connected into an electrical circuit and both length and diameter can easily be altered by 're-moulding' the putty. Although harmless, plastic gloves are provided to prevent hands from becoming stained. Approx. 100 g.