Circuitron
PS-1 Converter

Walthers Part # 800-5301, p. 290 Walthers 2012 HO Scale Reference
A scale, $14.95, currently in stock at Walthers

 
Highly filtered AC to DC converter. Maximum load capacity 1 amp, maximum input voltage 22V AC. Output is not regulated; voltage will vary depending upon input voltage and output load. (Requires transformer or power pack for AC input).