Power supplies for DCC Boosters

[Anonymous]

I Have a Digitrax Super Chief Booster and have succesfully used it with a simple 1.5 amp Power pack for testing. This is fine for the test track but now is the time to connect it properley to the new layout.

Problem is : I have a mains transformer 240V (I am in Australia) to twin independant 18volt output windings. The transformer is rated at 120 VA which to is about 9.8 amps at 16 volt. Does this mean that either winding can run 120VA or does it mean thta each is only 60VA. If I parrallel the windings will this be a good idea?

PS DCC on the test track makes me want to get on with the new Layou!

[cacole]

Transformer ratings are usually the total capacity on secondary windings, so your transformer probably outputs a total of 9.8 Amps if both secondary windings are in parallel. Wiring them in series will double the voltage to 32 but limit the Amperage to around 4.9, and parallel wiring will give you 16 Volts at the full 9.8 Amps. Most DCC boosters are limited to 4 Amps output to prevent the welding of metal wheels to track during a derailment. There's no harm in using a transformer with a higher Amperage rating, since the booster will limit the output. Feeding a higher Amperage into the booster will not harm it in any way, and can prevent voltage drops if you decide to double or triple head locomotives. Doubling the Voltage output to 32 could easily damage the power booster.

[Anonymous]

Thanks for your response.Since posting the message I have had a response by telephone from a local model railroader who is using exactly the same transformer. He agrees with you recommendation for paralleling the windings but to mount a 5 am circuit breaker in the box containing the transformer to limit the current outside the box with the transformer.

Happy Railroading. [:)]