It was designed for use on a `The London Model Railroad Group`s` large O scale layout located at London, Ontario, Canada. The prime requirements for the club throttles were that they be rugged, reliable and produce as little heat as possible. Throttles of this type have been in service at the club since 1987 with excellent results. The throttle will deliver 5 amps continuously and up to 18 volts DC. See Notes.
The Programmable Unijunction Transistor used to trigger the SCR is the key to this design as it ensures that the SCR fires on every cycle of the fullwave DC. This gives a very efficient operation with low voltage loss and very little heat generated. Pleas