Powering 1121 switches

[lionelsoni]

Turnouts like the 1121, 1122, 5121, and 5122 that do not shut off the switch-machine coil after throwing risk burning out the coil if a train stops on the control rail while voltage is being supplied to the switch machine.  They are all wired to get switch-machine voltage from the track, which makes it less likely that this will happen but does not guarantee it.  Converting these turnouts to a fixed voltage supply (which is not a trivial operation) greatly increases the risk of burnout, since a coil can remain on even though the train has been stopped by turning off the track voltage.

I strongly advise that anyone making this modification also implement a circuit that supplies current long enough to throw the switch and no longer.  I have many times posted information about how to build such capacitive-discharge circuits.  This kind of circuit also reduces the effect of wiring resistance on the supply voltage, reduces sparking as the train crosses the turnout, and protects the coils whether the train is stopped by turning off the track voltage or by cycling the e-unit, that is, under all conditions.

The simple capacitive-discharge circuit that I use is completely passive (series incandescent lamp, shunt electrolytic capacitor).  There are other, more complicated, ways to do it (http://cs.trains.com/TRCCS/forums/p/167351/2037720.aspx#2037720), but there is very little to fail in this two-component circuit; and the likely failure modes are all safe.

[traindood]

Hey Buzzardbreath:   the way i did it was like this: i don't know how you power your layout and i'm not an electrician but here goes: i have one dedicated line for switch power and one dedicated line for track power. mine  is modern zw's. connect  track power to one post and connect  switch power to another post.    hope this helps. later.

[ADCX Rob]

Agreed.

Necessary reading can start here:

Re: steady power for 0-27 switches

RE: Lionel 0-27 Switch Question

If you already have the non-derailing scheme worked out for your 1121's, the rest should come easily.

[balidas]

There is a way to power your switches separate from track power although don't ask me to explain it. It'd be easier for me to speak in Japanese. But if you search the forums for posts by lionelsoni, he explains in great detail how to do this as well as providing links for the parts you'll need.

[Buzzardbreath]

I am planning on using the non-derailing  set-up on my 1121 switches. But I would like to know if this will draw power from the track and slow down my train? If it does slow down the train is there an alternate way to power the switches like using a separate transformer?