Summary

Dual filament current regulator used in Philips type 1453 battery charger; also called resistance lamp.

A current regulator (ballast lamp or Barretter) uses an iron filament in a hydrogen atmosphere to produce a device through which the current is essentially constant over a range of voltages because of the large positive temperature coefficient of resistance of the filament. As the voltage goes up, the temperature rises, causing the resistance to rise, resulting in only a small rise in current.

Priced at 6 shillings in 1931 Philips radio catalogue. Manufacturer: Philips, Holland.

Physical Description

Base type: European style No. of pins in base: 4 Bulb shape: cylindrical Bulb material: glass Double filament (1 burnt out).

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