Really dumb question. For a Tortoise motor, do I need a switch with a center-off?
Richard
NO. I'm hooking up some Torts with on/off SPDT and bi-polar LEDs for panel indication right now, works good.
regards, Peter
You really do not want a center off switch, although it would work as long ans you never used the center position. Tortoise motors are what are called stall motors, that is they are designed to have power applied even though they are stalled. When you change the polarity of power going to the Tortoise, it causes the motor to reverse its motion which in turn causes the points against the opposite stock rail. Once the points are against that rail, the motor cannot move any more, thus it is stalled. By keeping power applied the points are held firmly against the rail. Use either SPDT OF DPDT switches, which ever you can find the cheapest.
If you were to turn the Tortoise off (center off) you would run the risk of picking the switch as there would be nothing to hold the switch to the stock rail. Still it could be useful for trouble shooting something. LIONS do not do that, but if you have center off switches and want to use them up, you could do that too. it will do no harm so long as you have it energised when a train is due.
Indeed, LION has modeled a GRS model-5 interlocking plant. On a GRS machine the switch is one way or the other.
A US&S machine on the other hand is a pneumatic machine using air to move the switch points. This DOES have a "center off" position whcih undoubtedly reduces the load on the air system when a switch is not in use. Here you must throw the switch ot either the Normal or the Reverse position before that switch can be used in a lineup, otherwise you will not be able to move the signal lever.
If you wanted to simulate a US&S machine, then this will do it. You can do some wiring logic to prevent a clear signal if the route is not correctly aligned.
ROAR
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