Bleed-free Power Source Selector needed - PLEASE HELP

Are you looking for a relay that will do this? This would allow you to have a small toggle switch that would switch between the two sources. 

Or do you want a bigger switch that can handle this by itself without a relay? 

Like a DPDT rotary switch from Amazon?

Uxcell 8 Terminal 2 Position Rotary Cam Changeover Switch AC660V 20A https://www.amazon.com/dp/B00R...cp_api_isSezbJWDSC58

A dpdt switch as mentioned above is the way to go.  I have done this same thing switch from dcs to conventional transformer without rewiring. And yes it cost you less than $15, likely less than $5.  Wire the track out put to the center and your sources to either side.

One has to specify the switch function and volts and amperage capacity. To connect the center terminals with the outside it's an ON-ON DPDT.

here is an On-On 10A handling.  The less expensive switches have less amperage handling. You want some headroom on the capacity.  These are solder lugs. getting blade connector lugs almost doubles the cost. Digikey ships quickly and is the least expensive. US mail in a padded envelope.

Remember that the TMCC signal has a way of jumping across free air.  I get the impression you're trying to block the TMCC signal from the second loop.  If so, you'll want to have an extra relay/switch contact that connects that outside rail to earth ground (3rd prong of outlet) to really kill off any radiated track signal to the TMCC electronics.

gunrunnerjohn posted:

Remember that the TMCC signal has a way of jumping across free air.  I get the impression you're trying to block the TMCC signal from the second loop.  If so, you'll want to have an extra relay/switch contact that connects that outside rail to earth ground (3rd prong of outlet) to really kill off any radiated track signal to the TMCC electronics.

No, the TMCC signal is welcomed all over the place. I am strictly trying to separate two different type of conventional power supply - 1) a modern powerhouse/TPC set up, and 2) a postwar ZW throttle - each to be used for the exact same track at different times (for different operators).

What about these? http://www.ebay.com/itm/5-X-12...c1FXa4Mp&vxp=mtr

Would those work??

I want to be able to toggle between the use of a ZW throttle and a Powerhouse via 15A TPC. Can both transformers be grounded together? (So I'm only killing the HOT out of which ever one I'm not using?) Or do they have do be wired and toggled separately for both HOT and COMMON, as if they don't even touch each other?

*PLEASE DON'T RESPOND WITH SOMETHING LIKE: "Just use an MTH TIU and Z-4000 if you want both throttle control and wireless control. Stop making this so complicated." - That's getting away from the point, snotty, and not answering the question. I'm working with a postwar ZW and a TPC set up for two different operators, each of who like the feel of one or the other for the same tracks, so I need to make this work as stated. Thanks.

There is no issue in having a common that is not switched, that's the way it's normally done.  Just switch the hot lead.

You can use a MTH TIU and Z-4000 as well. (just kidding)

gunrunnerjohn posted:

There is no issue in having a common that is not switched, that's the way it's normally done.  Just switch the hot lead.

You can use a MTH TIU and Z-4000 as well. (just kidding)

hahaha thanks gunrunnerjohn! ...that one definitely wasn't directed at you, but I know you already knew that 

You've been super helpful all around and that is much appreciated!

The devil made me do it, honest!

gunrunnerjohn posted:

The devil made me do it, honest!

LOL 

Say, any idea if this would do the trick?

http://www.ebay.com/itm/Heavy-...%26sd%3D152241133852

That would work. You may be able to find something similar locally. 

The key is DPDT switch rated for 10Amps or more. 

Why won't that switch work Carl?  I don't see any requirement for lighted switches or DC.  AAMOF, a SPDT switch will work for this application, so if switched DC was needed, there's a pole on the switch for that task.  All he's doing is switching the center rail, let's not make this more complicated than it is.

The OP made inquiries on two different switches - the first inquiry was for an illuminated automotive-style switch shown below on the left.  I think that is what Carl was responding to as no one directly answered that inquiry. 

The 2nd inquiry shown on the right is the DPDT switch that would work.  I notice it is a so-called ON-OFF-ON or 3-position style with a center-OFF.  So this would allow one, the other, or neither of the two transformers to reach the track loop.  I'd think you should be able to find this same switch in the ON-ON or 2-position style without the center-OFF feature.  It's not hard to imagine scenarios for testing or whatever where the center-OFF function can be handy.

Another consideration is how you are going to connect to the switch.  It appears the left style switch uses spade/blade quick-connect terminals while the right style uses screw terminals.  You may not have the "matching" crimp connectors or crimp tool lying around.  For the non-automotive switches as shown on the right, many offer options in terminal style.

DdotCdot posted:

What about these? http://www.ebay.com/itm/5-X-12...c1FXa4Mp&vxp=mtr

Would those work??

I want to be able to toggle between the use of a ZW throttle and a Powerhouse via 15A TPC. Can both transformers be grounded together? (So I'm only killing the HOT out of which ever one I'm not using?) Or do they have do be wired and toggled separately for both HOT and COMMON, as if they don't even touch each other?

*PLEASE DON'T RESPOND WITH SOMETHING LIKE: "Just use an MTH TIU and Z-4000 if you want both throttle control and wireless control. Stop making this so complicated." - That's getting away from the point, snotty, and not answering the question. I'm working with a postwar ZW and a TPC set up for two different operators, each of who like the feel of one or the other for the same tracks, so I need to make this work as stated. Thanks.

No, they won't work...well, the lights won't work. Lighted switches require DC voltage. if this case 12v. You could use an On/Off switch with one for each transformer, if that logic makes sense to you.

SPST toggle - On/Off

You could use a regular wall lighting switch for that matter - depends on what size and look that you want. $1.65 at most hardware and home stores.

Hot in/Hot out -Txfmr1   Hot in/Hot out/Txfmr 2

Go to a hardware store and look at what they have.

gunrunnerjohn posted:

Why won't that switch work Carl?  I don't see any requirement for lighted switches or DC.  AAMOF, a SPDT switch will work for this application, so if switched DC was needed, there's a pole on the switch for that task.  All he's doing is switching the center rail, let's not make this more complicated than it is.

Quoted wrong reply - corrected to first with a 12v illuminated automotive style, as Stan astutely observed.

Any links to a suitable double pole double throw switch with screw terminals for easier wiring changes than solder lugs?

ChooChoo1972,

Check the link in the post by DDOTCDOT from 5/11/17  6:31 PM - about 7 posts up in this thread and see if that would work for you.