Breckland Scientific 2021 Catalogue

Electricity & Electronics

Resistors & Resistance

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1 RESISTANCE SUBSTITUTION BOX An easily selectable range of 11 preferred value carbon resistors from 100W to 10W. Values (in ohms) are: 100R, 330R, 1k, 3.3k, 10k, 33k, 100k, 330k, 1M, 3.3M, 10M. Each range is rated at 0.5W continuous, 1W maximum. Housed in a robust ABS plastic case 75x100x40mm with rotary selector switch having an OFF position. Connection is made via a pair of 4mm sockets. Cat No. Description Price Per ELR-210-100 Resistance Substitution Box 45.00 ea. 2 LASCELLS DECADE RESISTANCE BOX A four decade resistance box covering 1Ω to 9999Ω in 1Ω steps. Resistors are 1% tolerance. Max current 0.35A. Power rating 1W continuous. 4mm sockets allow the unit to be used as a potential divider. Cat No. Description Price Per ELR-225-100 Decade Resistance Box 101.01 ea. 3 LASCELLS LOST VOLTS APPARATUS This ‘Lost Volts’ apparatus provides a convenient solution for experimentally determining the internal resistance and the EMF of a cell. The unit requires connection to a 6V DC source of EMF, a voltmeter and an ammeter. The unit houses seven appropriately rated resistors and a push switch and is designed to remove any complications from wiring separate resistors. The switch reduces the possibility of unnecessary drain of the battery and excessive heat being generated in the resistors. Cat No. Description Price Per ELR-235-100 Lost Volts Apparatus 45.46 ea. 4 RHEOSTATS (POTENTIOMETERS) Wire wound on a vitreous enamel 43mm dia. steel tube, using heavily oxidised resistance wire. The wire is held in place using ceramic cement to ensure longevity. A heavy duty sliding contact with multi leaf phosphor bronze strips runs on a separate bar. Termination is provided by 4mm screw/socket posts.

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Resistance Substitution Box

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Lascells Decade Resistance Box

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Max Current

Tube Length Price Per

Cat No.

Resistance

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ELR-250-100 1600Ω Rheostat

0.3A 200mm 31.00 ea.

ELR-250-150 600Ω Rheostat

0.6A 200mm 40.46 ea.

n

ELR-250-250 135Ω Rheostat

1.4A 200mm 39.00 ea.

ELR-250-300 55Ω Rheostat

2.3A 200mm 34.30 ea.

ELR-250-350 16Ω Rheostat

4A

200mm 36.53 ea.

o

ELR-250-400 8.5Ω Rheostat

5A

200mm 33.72 ea.

ELR-250-450 2.5Ω Rheostat

9A

200mm 33.72 ea.

p

ELR-250-500 1325Ω Rheostat

0.5A 300mm 33.30 ea.

ELR-250-600 125Ω Rheostat

1.8A 300mm 43.34 ea.

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ELR-250-650 37Ω Rheostat

3.2A 300mm 36.88 ea.

Lascells Lost Volts Apparatus

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ELR-250-700 20Ω Rheostat

4.5A 300mm 36.88 ea.

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Rheostat

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