Rotary Cam Switch or Phone Plug?

[Arto]

I’m installing a “scenic” programming track that can double as an independent (from main layout) single track point to point mainline.

 

The programming track also has to use both ESU LokProgrammer and DigiTrax PR3 programming interface.

 

I would like to install some kind of rotary cam switch to change the wire pairs from a DigiTrax Command Station/Booster, LokProgrammer & PR3 to the new programming track/mainline.

 

I bought a Taiss LW26-20 switch through Amazon which I now realize is the wrong product for accomplishing this. It doesn’t switch in pairs. Unfortunately I’ve already cut the holes in the control panel but it’s easy enough to make a new one if I really have to. Any idea what similar switch is correct for the job?

 

As an alternative, I’m also considering just doing it the old fashion way, using a ¼” TRS phone jack connected to the programming track with three female connectors on the panel to independently connect the Command Station/Booster, LokProgrammer & PR3 with complete isolation. My main concern doing this is the intermittent connection when plugging/unplugging the TRS jack. It seems to me that the phone jack “ring” will make contact with the “tip” female connection. I’m concerned this may cause a short or damage the Command Station/Booster.

 

What are your thoughts?

[Overmod]

Many of the phone jacks are designed so that the contact at the 'tip' that mechanically engages the little notch there to hold the plug in place also acts to close or open a switch when the tip 'leaves' the contact.  If this action takes place before there is any possibility of contact between plug and jack ring or tip surfaces... any current will be cut off before it can 'short'. 

On the other hand, it is not uncommon for plugs, as in stereo pin plugs where the two 'rings' use 'tip' as a common ground, to be made so the tip is made to engage ground contact purposely before either of the actual conductors 'makes' -- this is one of the 'safety features' built into those foot-destroying British 220V consumer plugs.

[Arto]

Thnx Overmod.

I think I may have found what I need in a rotary switch that fits the panel holes the same the LW26-20 I bought. The LW26-20 is labeled "0-4/2".

The one I just ordered is LW26-32 0-3/3, "0" being the completely OFF position (as on LW26-20 also). This one has 12 terminals (instead of 8). But I think the key here is "0-3/3". I need three positions that have 2 terminals that switch together.

Taiss Universal Changeover Switch 32A 690V 4 Position 12 Terminals Latching Rotary Cam Selector Switch + SV2-4s Blue Connection Terminal LW26-32 0-3/3: Amazon.com: Industrial & Scientific

If this doesn't work then I may have to try the phone jack route. I forgot about that "disconnection lift" built into some (all?) of those TRS phone jack recepticals.

[gmpullman]

The one you ordered will certainly do the job, maybe a bit overkill but should be quite durable.

I use rotary switches for several tasks on my layout such as controlling Tortoise machines on 3 way ot double slip switches.

I use this rotary switch:

https://a.co/d/5OmfZgp

About the same as the one you ordered. You'll only use two of the three poles.

This one, two pole four position, would work as well:

https://a.co/d/8PKGFCd

I use one for my test track where I have a Lok Programmer, JMRI Sprogg, MRC DC power supply or Digitrax command station selectable as needed.

 

Good Luck, Ed

 

[Arto]

Thnx Ed!

I recieved the new switch today & tested the terminal connections for continuity and everything works as expected this time.

You are abosolutely correct. It is overkill. Big overkill.

When I rebuilt the layout & switched to DCC I wired all the bus lines with 10AWG stranded copper, and multiple 18AWG feeders, equivalent to 10AWG/isolated block, every single track section has feeders. I didn't want any voltage drop anywhere and consistent wiring throughput for digital tranmission.