Wiring an Atlas switch machine without the Atlas switch control box.

[crossthedog]

In one place on my layout I need an automated switch machine because I cannot easily reach the spot, but there's not room underneath for a Tortoise because there's a track in a tunnel right under that spot. So I'm going to try an Atlas switch machine that I picked up for a buck at a swap meet, because it is still installed under the layout but has a very low profile. Here's a photo of the instruction sheet:

I want to wire the thing. Referring to the picture, I have the switch machine and I have a power pack, but I don't have the thing in the middle, the Atlas Switch Control Box(tm). But I don't think I need it. It seems to me that some kind of simple switch would do but I don't know exactly which kind. Am I right?

I recall the guy who sold me this saying something about making sure I use a switch that doesn't "stay on" but rather makes a temporary connection, like maybe one of those push-button switches that my old Tyco log dump used. Does that help?

Thanks in advance,

-Matt

 EDIT: The more I think about it, maybe what he said was, if I use a switch contol box like the one pictured, I should make sure that when I press/slide the button to activate the switch machine, I should only hold it for a second, or I'd burn up the unit. Yeah. Yeah, that's it. 

[gregc]

crossthedog

making sure I use a switch that doesn't "stay on" but rather makes a temporary connection

a momentary SPDT switch in both positions

 

[Water Level Route]

Not sure if you needed this much detail, but using a switch like what Greg linked:  One wire from the power pack goes to the center screw on the switch machine.  The other wire goes from the power pack to the center lug on the toggle switch.  The outer lugs on the toggle then go to the outer screws on the switch machine.

You could also do this with momentary contact push buttons as well.  Similar process, except instead of bringing one wire to the center lug of a toggle, you send it to each of the push buttons (daisy chaining them is easiest).  Then one wire from one push button to one outer screw on the switch machine, the other push button wire goes to the other outer screw.

[gmpullman]

On one of my early layouts I used "twin-coil" machines similar to the Atlas.

I wired them using a SPDT toggle with one momentary contact NO pushbutton on the common.

The advantage to this over simply using two momentary NO pushbuttons is that the position of the toggle handle will give you a visual clue as to which way the turnout is "most likely" to be thrown.

Atlas by Edmund, on Flickr

The coils work best with AC current and if throwing multiple coils, say for a crossover, a capacitor discharge unit is very helpful. Plus a CD unit will help prevent coil burnout.

Good Luck, Ed

[crossthedog]

@Greg, thanks for the quick help. That product is described by the seller as On-Off-Momentary. Does that mean that it has one position I can use for the momentary throw and that the other (ON) position should not be used at all?

Water Level Route

Not sure if you needed this much detail, but using a switch like what Greg linked: One wire from the power pack goes to...

Mike, that much detail is ALWAYS appreciated, at least by me. Thank you.

Water Level Route

You could also do this with momentary contact push buttons as well. Similar process, except instead of bringing one wire to the center lug of a toggle, you send it to each of the push buttons (daisy chaining them is easiest). Then one wire from one push button to one outer screw on the switch machine, the other push button wire goes to the other outer screw.

I like the toggle Greg linked to, but I was already starting to warm up to the idea of push button operation here, simply because it would prevent accidentally leaving the switch machine "on" for too long. I think I understand your instructions here, but why would I need more than one button?

gmpullman

The advantage to this over simply using two momentary NO pushbuttons is that the position of the toggle handle will give you a visual clue as to which way the turnout is "most likely" to be thrown.

Ed, What is a "NO pushbutton"? And yes, I've used this visual cue to advantage on a switch panel that handles turnouts that are up high and in the middle of the layout where it's difficult for me to see which position the points are in. My mnemonic is "Down for Divergent" -- if the toggle is up, the path is "straight" or "through" (it may actually be the outer path of a curved turnout) and if the toggle is down it follows the divergent route.

-Matt

 

 

[gregc]

crossthedog

That product is described by the seller as On-Off-Momentary. Does that mean that it has one position I can use for the momentary throw and that the other (ON) position should not be used at all?

i can't be sure, but it looks like the lever is straight up.   the lever is normally angled to one side or the other.

the mts-113 datasheet suggests that that particular switch is momentary in only one direction

you may be better off with separate momentary switches as suggested

[crossthedog]

gregc

the mts-113 datasheet suggests that that particular switch is momentary in only one direction

Would this one be momentary in BOTH directions? I'm guessing the parentheses around the ONs means momentary.

-Matt

[nealknows]

A push button switch with a 'NO' contact means when you push it the circuit is complete. I use these push buttons with my Atlas switch machines and have no issues - on ALL 147 turnouts! One is red for the diverging route and the other is a black or green. Very simple and straightforward. Not that complicated...

Neal

[gmpullman]

crossthedog

Ed, What is a "NO pushbutton"?

NO = Normally open (when no one is touching the button there is no continuity between contacts. Depress the button (or overcome the spring tension in a momentary toggle) and the continuity is "made".

NC = Normally Closed (when no one is touching the button there IS continuity between contacts and when the button is pressed the circuit opens, often used with a "stop" pushbutton which would open the relay circuit in a motor control setup).

Good Luck, Ed

[Water Level Route]

crossthedog

I think I understand your instructions here, but why would I need more than one button?

If you go with pushbuttons alone, you need one for setting the turnout to the diverging route, one for the straight route.  Ed's suggestion is a rather elegant one in that you have a toggle to help indicate turnout direction, but utilizing one in conjunction with a pushbutton allows you to use an easier to find on-on toggle or on-off-on toggle.  Momentary contact toggles aren't as common as constant contact toggles.  

Please, if I haven't made it clear, let me know.  I could sketch something up later when I'm home from work.

[crossthedog]

Water Level Route

d's suggestion is a rather elegant one in that you have a toggle to help indicate turnout direction, but utilizing one in conjunction with a pushbutton allows you to use an easier to find on-on toggle or on-off-on toggle. Momentary contact toggles aren't as common as constant contact toggles. Please, if I haven't made it clear, let me know. I could sketch something up later when I'm home from work.

I think I understand, Mike, and thanks very much. With your earlier instructions and reading each of the other posts, I believe I can piece it together.

I think the link I posted above goes to a momentary contact toggle of the type we're talking about, but I'm not certain, since you say they are hard to find. Can you take a look and confirm? Here it is again:

Momentary toggle

If this item fits the bill, I'm going to get a couple.

Thanks,

-Matt

 

[gmpullman]

crossthedog

If this item fits the bill, I'm going to get a couple.

This listing is for a quantity of one (1) SPDT Momentary mini toggle switch (ON)-OFF-(ON) w/ solder lug terminals. These switches are momentary, meaning that they always remain in the center position (OFF). Very high quality with a super light weight construction.

I think they are trying to convey that they are momentary, center-off.

Good Luck, Ed

[crossthedog]

gmpullman

I think they are trying to convey that they are momentary, center-off.

And that's what we want here, right? Center off would be like "Normall Off", or...?

[jjdamnit]

Hello All,

Is there a specific reason you don't want to use an Atlas Switch Control Box?

This is the simplest solution.

As has been mentioned investing in a Capacitor Discharge Unit (CDU) would be prudent.

The twin coil, solenoid motor can burn out if continuous power is applied. 

When triggered, the CDU emanates a single pulse to activate the solenoid(s).

This is a passive unit that is wired between the power source and the switch control box(es) or whatever trigger mechanism you use.

Even if you hold the button down, or toggle in the open position, the CDU will not fire another pulse until the unit recharges.

Recharge time is as long as the activation switch is turned off.

You can fire the unit multiple times in rapid succession. Only single pulses will emanate, and not continuous power, which will protect the solenoids.

Another advantage of a CDU is if you have multiple turnout motors in parallel, where you want both activated simultaneously, this will provide the necessary amperage to move both easily.

To move opposing turnout motors simultaneously simply reverse the polarity of one unit.

I have used the PECO CDUs (PL-35) with great success.

These are available in the U.S. Simply Google PECO Capacitor Discharge Unit.

Hope this helps.

[crossthedog]

jjdamnit

Is there a specific reason you don't want to use an Atlas Switch Control Box? This is the simplest solution.

Hmmm. It is a valid question. My initial thinking was, "I don't have one of those but I have some extra switches" and thought maybe I had one that would suit. And it snowballed from there. I do like the fact that the toggles being considered here don't take up a lot of room. I don't have a big space for control panel components. But thanks, JJ, this is a solution and I believe my LHS guy stocks these, maybe even has used ones in a bin for a buck or two.

-Matt

[jjdamnit]

Hello All,

crossthedog

"I don't have one of those but I have some extra switches" and thought maybe I had one that would suit. And it snowballed from there.

Often the problem with "the simplest" solutions is they do indeed snowball.

I'm a big fan of Rube Goldberg and his "simplified solutions" to common "problems".

Whatever your choice, I wish you success.

Hope this helps.

[gregc]

gregc

the mts-113 datasheet suggests that that particular switch is momentary in only one direction

if you look at the data sheet, switches are described as

• on  -   off
• on  -   on
• on  -   (on)
• on off  on
• on off  (on)
• (on) off (on)

i've not see this notation before.  presumably (on) mean momentary