Sources of "A," "B" and "C" Power for Radio Receivers

This paper describes and gives characteristics of the various present-day sources of "A," "B," and "C" power for radio receivers, namely, storage batteries, dry primary batteries, trickle-charge power units and battery substitute devices. The development of radio storage batteries from the earliest types up to the highly-specialized radio "A" and "B" batteries of today having built-in charge indicators, visible water level and spray-proof construction is traced and information is given on "A" socket power units containing such batteries in combination with newly-developed trickle chargers. Announcement is made of a perfected aluminum electrolytic rectifier. "B" battery substitutes embodying this rectifier are described and their electrical characteristics are given. Rectifiers and smoothing filters generally and their application to radio uses are discussed.