Powering Slow Motion Switches

Newbie Question Alert!

I just received four Circuitron Tortoise switches to be used on four turnouts on my layout. I’ve never hooked one up before and am feeling a little bit intimitated. I don’t want to blow them up![B)]

In the instructions it says that the switch should not be hooked up to a DC current of more than 12v. My DC power pack (Bachmann Magnum) has an output of 15v DC.

How do I power my switches? HELP![:0]

Trevor

well you could use some resistors to step down the power, or just buy a 12v power supply from radio shack. I use a 12v power pack I had in my junk box, not sure where it came from, old answer machine or cordless phone or something.

Thanks Javern for replying to my question.

Radioshack huh? Okay then. I’ll look there. When I get a power supply how do I go about connecting it to the switch ? Do I cut off the adapter on the end of the wire and the strip the wire and connect it straight to the DPDT switch? My concen is goofing something up and burning the house down… so please, no flaming at the apparent newbiness of my question.

Trevor [|)]

Trevor,
The above suggestions are all very good. If I may add, even with a 12 volt supply, you can add resistors in series to make the motor run even slower. All a matter of choice.

REX

Keeping it simple, here’s what you need.

From Radio Shack, get any one of the following: 273-1773, 273-1776, or 273-1779. Any one of these three will work, the only difference is the power output. 273-1773 is 500ma, which is enough to drive at least TWENTY Tortoises.

Cut the plug off the end. You just need wires. Take a look at the sheet that came withthe machine, it shows how to hook up a DPDT switch. First, take two short wires and make an X to the four corner terminals of the switch. Looking at the back where the terminals are, one wire should go from the lower left to the upper right, NOT touching the middle terminals. The other wire should go from the lower right to the upper left, again, not touching the middle. Run a pair of wires from EITHER the top or bottom terminals (but not both!) to pins 1 and 8 on the Tortoise machine. Connect the power supply to the middle terminals. Plug it in, and the Tortoise should move back and forth as you flip the switch.
Repeat for all. You can run a single wire from all center left terminals to the power supply, and all center right terminals to the other side of the power supply, you don’t have to run wires directly from each switch to the power supply. Just connect the power supply to the first switch and then run segments of wire to the next switch, and so forth.

–Randy

Many Thanks Randy. Excellent instructions! You just translated the Circuitron instructions to english for me.

FOLLOW-UP QUESTION: I just found a powersupply with an output of 9v DC. Is this enough juice to run 4 switches?

Thanks again guys,
Trevor[:)]

you can also hook them up to an old power pack on the terminals that control the speed of the train…as long as you don’t take it to full power it will work fine…I have over 40 tortoises powered by an old toy train tyco power pack that i keep on the 20 MPH speed which is putting out about 8- 10 volts…Chuck

Thanks Chuck[:)] I am guessing based on your answer that a 9v dc power supply should be ample power to run a mere 4 switches. [:p]

Trevor

9V will run them just fine. A bit slower, but quieter. Still pleny of power to hold the points in position.

If you intend to take advantage of the ability to put LEDs directly in series (I think that’s shown on the instruction sheet), then 9V might be a little low, because you’re goign to have the drop throught he LED. Best is to just experiment, so long as you don’t exceed the 12V rating, you aren’t going to hurt anything. If you have the 9V, try that first. If it’s not right, you can always go buy a 12V adapter.

The problem with using an old power pack is that the no-load voltage of most of them is too high. Perhaps a decent transitor pack would be fine, with the speed knob cut back - but then who has surplus QUALITY power packs? If you have a good one, it’s probably being used to run your trains. Old rheostat packs just won’t work - even if you had a dozen Tortoises, the load is too low and the voltage will run to maximum, around 15v as you found out. Even a cheapy power pack typically can put out 1 amp. Each Tortoise draws around 10ma. That means it takes 100 Tortoises to load down that power pack. 50 just for half load. ith 4 - it won’t even notice they are connected.

–Randy