Switches

[Anonymous]

Can switches be powered either ac or dc? I was given 2 power packs so what I want to do is power switches, lights etc. with one power pack and leave the other newer one strictly for trains, so can I run the switches on dc which is my preferred method?

[rrinker]

Tortoise-type switch motors NEED DC. Atlas-type can work on either, but I'm not sure why you would want to runt hem ont he DC side of the pack. You'd be better off using the AC side, and using the DC side to control structure lights - you can turn it down so the bulbs are running on less than rated voltage, they will last longer and look better.

--Randy

[NZRMac]

Atlas type are best switched with a capacitor discharge unit, so they don't burn out. A very quick pulse and it's all over.

Ken.

[selector]

My EZ-Track electrical switches are wired to my AC posts. All they need is to slide the button right or left, and I believe that a solenoid, activated by a capacitor, snaps the points over, but Randy would know better. An LHS owner in Victoria told me that any bulbs should be handled by DC for the same reason as Randy said; you control the voltage, and therefore how hot/bright they get. Brighter, as in stars, means a shorter life.

[rrinker]

Well unless you installed one, there's no capacitor. If you don't have one, consider getting or bulding one, a capacitor discharge power supply is a wonderful thing to have. The switches will snap with greater authority, yet you will have practically zero change of burning them out, even if the button jams. I built one many years ago when I last had an N scale layout (and last used snap action switch machines) and it was the best couple of bucks I ever spent at Radio Shack (for the parts). I was buring out the (more delciate) Atlas N scale motors at least one per month until I built the CD, after that, never again.

--Randy

[dinwitty]

Atlas styled switches use a selenoid, they can be controlled AC or DC, but a Capacitor Discharge unit will use DC, but you can rectify/filter the AC to DC.

Oyes you want lights separate, get that day/night effect, turn them room lights off...
.

[Medina1128]

I remember that 10 megaton <CLACK> using Atlas switch machines. With my new layout, I'm going with the more prototypical tortoise machines. You can always wire in a rheostat to use AC to power the lights (that's what your light dimmer in your home is)...

[selector]

So, Randy, if I were to go to RS and get a capacitor, could you give me the paramaters, and how & where would I use it? Wire it in series after the slide switch, or what?

[rrinker]

You need a capacitor, a diode, a couple of resistors, a power transistor and a heat sink for it. I believe a variation of the circuit is on Rob Paisley's site, but the one I built is from the book Practical Electronic Projects for Model Railroaders, by Kalmbach (out of print, I believe). I can get the parts list out of my copy, but I can't photocopy or scan the page. I suppose I could draw an equivalent circuit , but that would only be a schematic.

It goes between the power supply and the first of all the buttons - ie, disconnect pwer supply where it goes to the switch controls, connect power supply to input of CD unit, connect output of CD unit to the switch controls where the original power supply was connected.

Here's the page from Rob's site: http://home.cogeco.ca/~rpaisley4/CDPSU.html

The one I built is like the one shown as B in the first set of diagrams. Under the section "current blocking switch machine power supplies", the top one is the same circuit with part values given. Where he shows a transformer and fuse connected, connect the AC terminals of your power pack. Or use fixed DC and eliminate the 4 diodes. I'm pretty sure all those parts are available at Radio Shack, I can make a list if you want.

--Randy

[selector]

Thanks, Randy, but I should have been more clear. I meant can I buy a manufactured CD, and if so, of what type?

When you say in front of "the first of all the buttons", I take it that the switch controls can be hooked together, or plugged into each other. At least, that is what the directions suggest to me. How the heck you control switch A with connected controls and not get all of them 'clacking' is beyond me.

Edit- On second thought, I guess that the hook-up is a way to power all of them, but sliding a given button will only activate the switch to which it is connected? Oy, I got such a headache!

[rrinker]

The Circuitron Snapper is a nice commercial CD supply. Ready to go, just hook up the 4 wires, 2 in, 2 out.

Yes, all the little slides hook together for POWER. Otherwise one button to a switch machine, except maybe on crossovers where you can easily connect both switch machines for the crossover to one button so you alwyas get a valid route.


--Randy

[selector]

Thanks, Randy. Another project, but this one will wait until the rains come in November.