Issue with wireing, any 10amp DP4T rotary switches?

Here's what RichO came up with for the CWRR Eagle Scout project at the museum. We have 3 levels connected by a helix. We need 3 separate levels to run 3 trains conventionally at fixed voltages for museum operation. We have isolated the levels from one another where a rise of the helix meets the next level switch(es). Each has it's own transformer.

The layout was designed to run as one mainline with different routes between levels. We wanted the ability to run it that way for "run days" for us and/or guests under supervision.

It was cost effective to use just DPDT toggles. Each level can be tied to one transformer or one channel of multi-channel transformer by flipping all three switches to the second position.

PLCProf posted:

There are a number of choices, but they aren't cheap.

1. Why do you need to switch the U terminals?

2. What is the budget?

1. Because I have the gauge set for the ZW-C, and it'll read wrong if the power and U terminals are not properly paired.

2. None set yet.  I'm looking at about $80 if I go the relay board wiring mess my co-worker came up with.

Wow, that is pricey.  I'm going to keep looking.

Sounds  like  our conventional  cab control days with our trusty KWs.    2 pole double throw center off toggles so one could assign power to either A or B handle.

Any rotary switch I've used put out power  momentarily when rotating the switch so when going from a to c loop and shot of power also went to loop b.  Not what you want, There must be some 4 pole double throw, center off  toggles out there someplace.??

Some more digging on DigiKey found me this switch, which is non-shorting.  Price is better, but still up there.

Hopefully you will be making a switch between positions with the power off.  Otherwise you may have issues with arcing the contacts of the switch at those current levels.

sinclair posted:

2. None set yet.  I'm looking at about $80 if I go the relay board wiring mess my co-worker came up with.

Is that $80 per DP4T or for all 4 channels?  Here are some eBay DPDT 10A relays for $2.39 each with free shipping from Asia.  They include sockets with screw-terminals which can simplify hookup. 

The idea (which might be what your co-worker suggested) would be to use a low-cost, easier-to-find SP4T switch which would apply 12V DC to one of four DPDT relays.

So out-of-pocket cost for the first DP4T would be about $15.... ~$10 for 4 relays, ~$3 for an SP4T, and ~$2 for a 12V DC wall-wart power adapter.  The same 12V DC supply could be used for additional DP4T so, say, $13 each.

It's not a space-saver by any means but some possible benefits would be ease of adding LED indicators for a control-panel, more selection in style of rotary switch, and ease of implementing an emergency "all-off" position by simply cutting 12V DC relay coil power via a low-cost wireless remote.

I would buy somehting like this and wire the less expensive rotary switches to it. These are active lo so the 5v + goes in and you switch the GND or 5V negative side. Then if you wire a power switch in to the 5V + side you can shut off the power to the layout by turnig off the power to the relays

5QAAOxyoExSCJN6" target="_blank">http://www.ebay.com/itm/8-Chan...8:g5QAAOxyoExSCJN6

8 channel 10A relay board from china:  $4.61 shipped ($7.59 US Seller)

1Amp 5v power supply from china:  $0.99 shipped.  ($2.49 US seller.)

4 position rotary switches from hong-kong:  $1.25 each. ($6.79 US seller.)

if you want you put the whole mess in a project box for about 10 bucks, but I would just mount the switches in a control panel and call it a day.  

Assuming you have a couple feet of wire laying around already, the set-up should cost well under $15 if you have a couple weeks to wait for parts from china.  

On the scale of wiring a layout, there shouldn't really be any practical difference in running track power through switches, or running it through relays triggered by switches.  

For another couple bucks in parts you could add block control from TMCC/Legacy if you wanted.  

One bonus of relays is that you can locate them closer to the switched sections, you may save long runs of wire.  It's probably cheaper and there's less voltage drop.  The small control wiring is a non-issue as far as voltage drop.

John, he wouldn't want to run 4 power feeds to each remote relay cluster.  Better to have the relays at his ZW-C with just the 4 switched track feeds fanning out to the track.

Perhaps true in this situation, but the relays give you the flexibility, depending on the situation.

These eBay relays are what my co-working is looking at, 8 of them total.

As for switching when powered, the 12amp break before make switches I found would work when powered too.  But the price is still kinda high.  I've got a bit of time to decide anyway.  I really need to see just how much space the relay system would take up, including the need for an extra plug.

If you're OK with doubling up on SPDT relays to perform the double-pole function,  as the other guys show you ought to be able to shop around on eBay or wherever and lower your cost-per-relay by choosing a version with 8, 16, etc. relays-per-module.  Some may use a square-pin header connector for the power/control inputs (if the module does not have screw-terminals).  But the connector that converts the square-pin header to flying leads are less than $1 on eBay.  It appears that some of the hi-current DP4T rotary switches require soldering fat-wires to the switch contacts; using relays with lo-current SP4T and thin-wires might simplify the soldering-chore.