Rotary switch and turntable wiring

I have s rotary on my roundhouse tracks I just turn it fast I don't know if it hurt's

them I haven't had any problems ,you could put a toggle switch before going in to the rotary that would kill the power and solve the problem .

Guy

Do a search for "Wiring turntable whisker tracks" from last month.  There is a good discussion on this.  As Guy stated, using a toggle switch before the rotary switch seems to be the preferred method.

Ron

Ed, here's the topic Ron was talking about. I'll save you the trouble of a search. My opinion after that discussion, keep it the way you have it with on/off for each track.

Rotary switches come in "make before break" and "break before make". You want the latter. Look for something like Centralab switches and browse thru them.

Folks,

Thank you for all the good information and the variety of solutions.  I have to go over the ideas some more to see which one makes sense for me to implement.

Stan - you talked about a 1 second delay relay.  That seems like it should be long enough to cycle thru the positions.  Just as an FYI for me, can you also get them with a little longer delay, ie 2 seconds?

Jack - the break before make rotary switch also sounds like it would do the job.  Pardon me for asking what is probably a simple question.  I am not quite sure how the break before make rotary works.  Is there some delay between the break and make.  I guess my real question is how it works when you cycle thru the positions, ie will it prevent power going to each of the tracks as you cycle to the desired position.

Thanks everyone for the help.

Ed

Make-before-break has a switched contact that bridges two adjacent fixed contacts, so that power is fed, momentarily, to the one being turned off and the one being turned on, at the same time.

Break-before-make has a switched contact that does not bridge the adjacent contacts, so there is no feedback between the adjacent circuits.

The method of a master switch in series with the main feed, left OFF while switching among tracks, is the easiest and cheapest solution.  If you proceed with that scheme, the make/break question on the rotary switch is not an issue.

I have 7 sidings and use lighted auto rocker switches.

Both the individual switches on each stall and a rotary to switch on only one track at a time have advantages depending on your type of control system.

For command control 1 switch to turn on all stalls at once works great on a TMCC Legacy or DCS or DCC (HO)systems as long as no conventional engines are on any of the tracks. With conventional engines some engines will end up in the pit.

A Rotary that turns on only one track at a time works best with conventional engines but not as well with TMCC, Legacy DCS since you only have one engine powered up at a time. For TMCC Legacy and DCS you can't have multiple engines fired up at the same time.

With a power switch on each stall you can power up one, none, all or just a few which works great with conventional or command control systems.

I inherited an HOn3 layout with the turntable wired for DCC so that one switch powered up all stalls at once. This didn't work to well with conventional DC brass engines when they all ended up in the pit. I rewired it so the engine house power switch powered up the rotary switch which worked great for my conventional engines. Now I've converted to DCC and will have to remove the rotary and install individual switches on each stall.

If someone uses the lighted rocker switches like the Caltron brand, which mounts in a round hole, they can run a common wire to all the earth negative terminals and connect that thru a diode pointing to, and connected to the U terminal of their track supply. Since the LEDs only conduct for a half cycle the average voltage on them is then less than 12 vdc. And the diode will protect the LEDs from too high a back voltage from the other half cycle. This works for me for a number of years.

If you do use rotary switch, check that its contacts can handle 1-2 amps continuous current.  Alot of rotary switches are designed for light duty signal handling and might handle heavier current a few times before combined contact resistance and current heats the contacts so they lose their tension and become intermittent.  And/or the light weight contacts pit and burn as connection is made and broken.

Well, here I'm quoting myself but in another thread a $2 (eBay) relay module with turn-on delay was just discussed.  So IF going with the relay method, the intermittent turn-on "problem" could be solved with reasonably-priced off-the-shelf modules.  The turn-on delay is set with a screwdriver adjustment.  So the configuration is as shown below which allows a low-current rotary switch which might save on cost and provide more selection of styles.  I also see the terms "shorting" and "non-shorting" are alternately used to describe make-before-break and break-before-make.  In any case, with the relay method using time-delay, either switch type is OK without the need for the toggle switch.