Using a Separate (Additional) Booster to Create a Stationary Decoder Bus

Why the Hare/Wabbit Auto Throw needs a booster common connection?

By Don Fiehmann
September 18, 2008

Hare | Wabbit

Operating turnouts with accessory decoders makes it easier to run a railroad using a handheld cab. That is until you have a short in a block that cuts off the power to the accessory decoder. The solution is to power the accessory decoder from a separate source.

On my layout I have put in a separate booster to power the increasing number of accessory decoders I’m installing. This prevents a short in the block from shorting out the power. This all worked very well until I found that the Auto Throw feature on the Hare was not working.

I checked the wiring and it was OK. Why had this feature stopped working?

This was one of those types of problems that you think about and in the middle of the night a thought pops in to your mind. The added booster power was connected to the decoders and operated OK, but there was no connection to the rest of the layout. An added wire to connect the two boosters together was all that was needed to correct to problem.

This is the same problem that occurs when a brass steam engine crosses the boundary between two boosters and stalls. The engine picks up power from the engineer’s side and the tender picks up power from the fireman’s side.

Caution: If you are using Auto-Throw, be sure that the booster track outputs are wired to the same polarity. If the turnout points are powered from the Tortoise/Hare stationary decoder bus and the track is powered from the mainline booster, and the polarity is incorrect, one booster will backfeed to the other and possibly destroy one or both boosters.