Electricity

Comprised of two or more brass blocks fitted with brass terminals and mounted on a black bakelite base. Tapered plugs with bakelite moulded tops fit into the tapered holes between the blocks providing low resistance contact. With rubber feet.

To produce high voltage alternating current or pulses of high voltage current from a low voltage direct current source. Suitable for use with gas-filled discharge tubes, vacuum tubes, eudiometers and for general laboratory work.
Comprised of two coils fully enclosed in a polished wooden case with binding posts. Includes adjustable vibrator system, primary current polarity reversal and off-on switch, a condenser enclosed in the box and special alloy contacts. Spark gap at the discharge points can be adjusted by sliding rods back and forth. Requires 6-12 volt power source such as a battery.

For laboratory use as a variable series resistance or as a potentiometer. Can control current and voltage.
Made from heat resistant, air cooled, hollow porcelain tube closely wound with a resistance wire of copper nickel alloy which is previously oxidised to provide perfect insulation. The end supports are made of metal with provision for screw mounting. A bakelite slider carries a phosphor bronze contact which can be moved rapidly and smoothly and can rest anywhere along the winding. The insulation is sand-papered off where the slider makes contact. Resistance in ohms and current carrying capacities are engraved on contact carriage. Three terminals are provided for electrical connections, one at each end of the winding and the third at one end of the slide rod so that the unit can be used either as a rheostat or as a potentiometer.

Available with a variety of resistances and current carrying capacities.

Power ratings (watts) can be calculated as
Watts = (Current in amperes)2 x Resistance in ohms

Useful as a basic component for any electrical laboratory.
Mounted on bakelite base. Allows visible connection for easy use. With screw holes and suitable for bench fixing and panel mounting. Available in four configurations.