Wiring an Atlas turnout

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davmaur
Posts: 2
Joined: Sat Mar 13, 2021 6:23 pm

Wiring an Atlas turnout

Post by davmaur »

I am using Atlas under-table turnout controls on my layout. I have the Atlas #56 toggle/push button switches but would rather use common DPDT toggles on my control panel. The Atlas turnouts require ~16VAC power input. Does anyone know how to wire a DPDT toggle for these turnouts?
bsuarez
Posts: 30
Joined: Sat Mar 06, 2021 9:28 am

Re: Wiring an Atlas turnout

Post by bsuarez »

You can't use a straight toggle switch, you need momentary contact. You could use a SPST center off switch where you move the switch from center to either "throw" position and back to center. But if you forget you could easily burn out a switch machine. The Atlas turnout controllers are a combination of a slide switch and push button momentary contact.

If you were to use a SPST center off toggle switch you would connect on side of your power source to the middle contact and then each side would go to the outside posts on the switch machine. The center posts would all be fed by the other side of your power source.

Consider, instead, using momentary contact normally open micro push buttons as another option. Something like these: https://smile.amazon.com/DIYhz-Normal-M ... 165&sr=8-5

Good luck
earlcory
Posts: 1
Joined: Sat Mar 06, 2021 8:42 pm

Re: Wiring an Atlas turnout

Post by earlcory »

I use a monetary contact switch that is connected to an Arduino. The Arduino is programed to know which direction the switch is in and send a pulse thru a relay to throw the switch. Using the method you can also gang two or more switches to be thrown at the same time. This could also be done with just a SPST switch where on would send the switch one way and off the other. The Arduino and the relays would control the actual voltage and duration.
davmaur
Posts: 2
Joined: Sat Mar 13, 2021 6:23 pm

Re: Wiring an Atlas turnout

Post by davmaur »

Many thanks to both earlcory and bsuarez for your great suggestions. I will be investigating both ideas to see which works best for me. :)
Scott
Posts: 2
Joined: Wed Mar 17, 2021 12:06 am

Re: Wiring an Atlas turnout

Post by Scott »

You may also want to consider employing a capacitor discharge unit (CDU), particularly when throwing multiple turnouts simultaneously. I use Circuitron's Snapper, which comes as a small circuit board with accompanying mount. I also use the Atlas #200 Snap Relay which has two isolated sets of SPDT contacts to show switch status and switch frog power polarity. The Snapper CDU is perfect for this application, because I'm throwing three relays at once, and my old 18v ac accessory transformer was insufficient for this. I found a cheap 24v ac wall wart supply used for irrigation systems, which gives enough power to throw all those relays with authority, plus the Snapper CDU's output is only momentary, and will not recharge until your switch control contacts are opened, thus preventing any coil burnout.
pops.somerfield
Posts: 1
Joined: Sat Apr 17, 2021 9:08 am

Re: Wiring an Atlas turnout

Post by pops.somerfield »

To davmaur. I have the same situation with my layout. What I have done is to replace the Atlas switches with a SPDT 3 position momentary switch. Momentary meaning it is only powered when holding the switch in the ON position. Otherwise the switch returns to the center (off) position. These can be found on e-bay. Search "SPDT MOMENTARY SWITCH.
These switches have 3 connection lugs for wiring. Wire the center lug to power and the other 2 to your normal and reverse, as you would for the Atlas switches.
The only "problem" I have is there is nothing to indicate which direction the turnout is thrown, as the toggle has returned to center position. I have rectified that situation by also wiring in LEDs (green and red) to indicate normal or reverse via the use of an Atlas #200 Snap Relay. You can also use the relay to power the Frog of your turnout. For easy wiring instructions and explanations get The Complete Atlas Wiring Book.
Hope this helps in your search for solutions.
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