This (my ignorance) is what happens when in naive stupidity of youth, you muck around the insides of a turntable while blithely ignoring the fact that the said turntable is still plugged into the wall, and end up getting a jolt that scares you from anything electrical for the rest of your life. Well, I’m trying to overcome that, and MRR hobby is doing its part to help! [:D]
I’ve got two 6’ long shelves that hold in total four test tracks (two HO and two N gauge). Each track has its own power feeder cables. I’m looking for a switch that I can connect the four sets of feeders on one side, and have the power pack connect to the other side. Then I could choose which track to power, without having to connect and disconnect different sets of power cables each time. A bonus would be the ability to power more than one track at the same time.
I’m sure there must be a simple power switch like what I’m describing, but I honestly don’t even know where to look. Any help, especially web link, would be much appreciated.
The usual method would call for a little panel with four separate switches, one for each track. You can connect one rail (say the one closer to the wall on each track) to a common feed to one side of your power supply. The other power supply feed goes to all four switches, which are single-pole single throw and can be anything from miniature slide switches to the kind of light switch mounted in your room wall (although the latter would be gross overkill!) Then connect the other rail from each track to its own switch - preferably in a logical order. By throwing only one switch to ON, you would only power the one track to which it is connected. If you throw more than one switch ON, you will have power to more than one track. (Why? Locomotive races?)
The single-switch answer calls for a rotary switch, which will power one track at each position and have at least one position which is dead. The basic wiring remains the same. However, if you use a rotary switch you can only power one track at a time (which, for the arrangement you described, is not a disadvantage.)
Chuck (modeling Central Japan in September, 1964 - analog DC, MZL system)
I would reccomend DPST switches, thus having the ability to completely electrically isolate a track. SPST just opens the circuit, but if the mistake is made and the common is switched instead of the hot, then the track remains potentially energized. No big deal as its just 12Vdc, But using a SPST switch, an electrical fault on one of the “off” tracks can still affect the others & the power pack. Plus, if hes a bit “electricity jumpy” from taking one or two good shocks in your life, then having the comfort of total circuit isolation is worth the few extra cents spent upgrading from SPST to DPST!
I took 500Vdc through the heart in the engineroom of a submarine due to incomplete circut isolation… so its a near and dear thing to me! It maybe only 12Vdc, but giving the right effort, someone can kill themselves with a AA battery!
Thanks for all the replies. I have done SPST wiring before to isolate sidings, but I didn’t think about its application to this purpose.
I’ve found an Atlas connector switch (part no. 205) that has 3 SPST switches built-in, that can be coupled to additional 205 switches. So a couple of these will take care of my situation, it looks like:
You could also hook one rail of each track up as a common as suggested and then hook each of the other rails up to a rotary switch (You may be able to get one at Radio Shack). Then you can simple turn the switch to 1, 2, 3, or 4 to select which track you want.
You must’ve missed the part I wrote about being an ignoramus with a fear of electricity! [:D] The benefits sound great, but it seems pretty complicated to my untrained eyes.
Taking this a step further–where can I buy DC light bulbs that I can hook up to the test tracks that will light up when the track is powered?
I’d obviously prefer lights that will turn on to full brightness at a very low voltage threshold, and not get burned out as more power is applied to the track. Which would rule out most of the headlight-type light bulbs that grow brighter with more power.
Thanks for any help. I do appreciate the good advice people here have been giving so freely.
Thank you all for the helpful suggestions. I manage to wire it up this evening AND got it to work, to my not-inconsiderable surprise! This is what I ended up doing:
I used an Atlas SPDT selector, which wasn’t strictly required (SPST would’ve done fine), but I had one on hand and besides, the SPST gizmo from Atlas only had three switches, and I needed four.
I took 500Vdc through the heart in the engineroom of a submarine due to incomplete circut isolation… so its a near and dear thing to me! 
