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Atlas Snap Relay

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Atlas Snap Relay
Posted by camarokid on Wednesday, December 15, 2004 5:20 PM
Is it possible to energise two turnout frogs from one relay? I know this sounds stupid but would really like to know? Thank you for any considerations of this topic. Archie
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Posted by Anonymous on Wednesday, December 15, 2004 5:50 PM
With an Atlas Snap Relay it's possible to do as many as you want at the same time, or that's what the directions say inside the box. I bought about 6 of those a few years ago & haven't ever figured out how to wire them up. I bought the latest Atlas wiring book about a year ago, but that didn't help either. Now, I have a friend trying out a few on his layout & he's an electronic nut, so, if anyone can figure out the wiring diagram, he's the one. If it's anything more than a simple wiring job I'm confused.[banghead]
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Posted by camarokid on Wednesday, December 15, 2004 6:39 PM
Larry66: Thank you for the reply. I too have the same problem. It's very confusing instructions. Archie
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Posted by willy6 on Wednesday, December 15, 2004 6:58 PM
Yes it is, as long as they are in operation at the same time. Relays are magnetic latching and some are hermatically sealed. The purpose of a relay is to switch amps with a minimum of voltage.
trains
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Posted by Anonymous on Thursday, December 16, 2004 12:57 PM
Hi,

I had a similar question a while back ("1000ma AC - how many relays" was close to the subject line.) Anyway, I didn't get, shall we say, 'overloaded' with responses, so I did my own experimentation as follows:

1. I didn't trust the ac accessory outlet on an old power supply I had, so invested in a 1000ma, 18v ac supply from Radio Shack.

2. Experimentation *proved* to me that the current requirement of the snap relays on the turnouts and the snap relay machines (Atlas 200) was such that no more than 2 devices could be snapped reliably at any one time..... One turnout coupled with one Atlas 200 (or another turnout) is the limit.

3. Why is this significant? - Refer to Atlas HO layout #21 ("The waterwings") for an example of a double crossover wherein one switch control box is (supposedly) used to flip all four turnouts at once..... This does not, and as far as I have determined, cannot, be driven successfully as shown due to (2) above.....

Which kind of sucks! - Particularly if in addition to the turnout coils themselves you also want to power the frog(s) and/or some indicator lighting as per the instructions with the snap relay.....

I investigated some of the circuits referenced in replies to my original post, and wound up exploding a few capacitors before finding the following part at Walthers:

"Circuitron Snapper switch machine power supply" - Part # 800-5303. It hasn't arrived yet, but claims to be able to switch between 5 and 10 coils from a 24v supply.... This still seems like an awfully broad specification to me (!) but will hopefully get me out of trouble on this project.... (I need 4 turnouts plus two snap relays to do what I want.)

In conclusion, I remain absolutely amazed that this is not a bigger issue - Any time you have a need for two turnouts to be thrown at the same time (see Atlas layouts 22 & 23 for further examples) you better not try and add any further load if you want it to work reliably.....

If anyone could correct me on anything here I would love to hear.... Anyone at Atlas know how to make plan HO21 work?.....

And finally, while I'm on my "high horse" I took the advice of the masses and used AC to power the turnouts - The first thing the Circuitron (or any other homemade capacitive device) has to do is feed a rectifier to get DC to charge the capacitors..... Hmmmph!


Hope this helps,
Ian
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Posted by cwclark on Thursday, December 16, 2004 2:12 PM
you need to build a capacitor discharge unit for coil type turnouts..it's one of the easiest electronic projects...the kalmbach publication "electronic projects for model railroaders" has the diagram and the parts list to build one... now to your question...i used to use atlas turnout machines and atlas relays all the time and i could only get them to throw two machines at one time...the capacitor discharge unit should help to throw more but from my experience the momentary slide push button switch only does two at a time...chuck

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Posted by camarokid on Thursday, December 16, 2004 4:27 PM
willy6: Thank you. Yes, they will be. They are 20 feet apart.
fast_ianb: Thank you. I too had that problem on my old layout. So this time around I'm going to use 16 guage wire instead of doubled 20. Perhaps I should take a look at the Circuitron too. All I need is 24v power supply.
cwclark: Thank you. I have the book and will study it tonight(16Dec04). I had planned on wiring the relay this weekend but my granddaughter is coming for Christmas and will demand most of my time along with her mother(my oldest) and her husband. Maybe I can get him to help. Again, thank you to all for your help. Merry Christmas.
Archie
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Posted by JBCA on Thursday, December 16, 2004 5:12 PM
I'm back in the hobby after 30 years in remission and have exactly the same problem. My power supply for the switches is 800 milliamp and trying to power two at once is hit and mss. Methinks I'll try the Radio Shack 1000 milliamp (1 amp?) unit.

BTW being out so long I bought 15 Atlas snap switches -- didn't know custom line existed, they look much better, oh well for the next phase.
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Posted by Anonymous on Thursday, December 16, 2004 5:38 PM
jbca - Radio Shack part #273-1690 is the thing I got - It does both 18v and 24v ac - I haven't tried 24v (as yet :-) but I can guarantee that it will drive 2 (not 3!) 'devices', be they turnouts or snap relays - You just gotta be careful never to switch more than this at a time......

I'm still amazed that this doesn't seem to be more of an issue to people.... As I said above, there are at least 3 layouts out of 11 in the book (Atlas #11) which will not work if assembeld with, eg, powered frogs (requires a 3rd, or 4th relay) or remote, or panel lights etc etc.....

Anyway,

Good luck!
Ian
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Posted by rrinker on Thursday, December 16, 2004 7:42 PM
QUOTE: Originally posted by JBCA

I'm back in the hobby after 30 years in remission and have exactly the same problem. My power supply for the switches is 800 milliamp and trying to power two at once is hit and mss. Methinks I'll try the Radio Shack 1000 milliamp (1 amp?) unit.

BTW being out so long I bought 15 Atlas snap switches -- didn't know custom line existed, they look much better, oh well for the next phase.


800 milliamps isn't much. 1 amp isn't much more, when it comes to operating twin-coil switch motors. the short term current requirement can easily be 5x that. But the worst thing you can do to compensate is use a larger transformer, the internal loses inthe transformer will soon render the resulting system far too wasteful, and you'll spend a fortune on a heay duty transformer. All you really need is the capacitor discharge circuit, and the 800ma power supply will be PLENTY.

--Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by walshrd on Monday, June 12, 2017 4:12 PM
Use a capacitor discharge unit! They are easy to build and will supply all the power you need to throw as many SNAPS as you want.
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Posted by richhotrain on Monday, June 12, 2017 4:45 PM

Thank you so much. I have waited nearly 13 years for an answer to this question.  Laugh

Alton Junction

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Posted by BigDaddy on Monday, June 12, 2017 5:09 PM

richhotrain
Thank you so much. I have waited nearly 13 years for an answer to this question.  Laugh

Poor Archie hasn't posted in 6 years, he missed it.

Old thread stars;  StarStarStarStarStar

On second thought, Walshrd we don't mean to be rude.  Welcome to the forum.  Welcome

It just that newbies commonly do one of 3 things;

a) They answer a "vintage" question that has been asked by someone, who is now only identifed as Anonymous, because they haven't posted in years

b) They ask a question with so little information that it's impossible to give an inteligent answer.  "My engine doesn't run right"

c) They start what I call a "Drive By" thread, because we aren't allowed to call each other trolls.  The regulars end up arguing with one another about the "best radius" or the "best engine" or "DCC is dead" or some such nonsense and the newbie is never seen again.

Actually a bunch of us have dredged up an old posts without realizing it so there is no great harm.  We have every expectation that you will be a contributing member of the forum.

 

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by richhotrain on Monday, June 12, 2017 5:18 PM

BigDaddy
 
richhotrain
Thank you so much. I have waited nearly 13 years for an answer to this question.  Laugh 

Poor Archie hasn't posted in 6 years, he missed it.

Old thread stars;  StarStarStarStarStar 

Bang Head

Alton Junction

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Posted by MisterBeasley on Monday, June 12, 2017 6:59 PM

I still don't know what he was really asking.

If the idea is to energize two frogs on a crossover, where two turnouts are thrown together all the time, then sure, one snap-relay will work.  If the idea is to somehow use it to power two independent frogs, then it's probably not going to work.

These things are usually wired in parallel with a switch machine, so yes, a CD circuit is the way to go.  Even if you don't have snap-relays, a CD circuit is the way to go.

It takes an iron man to play with a toy iron horse. 

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Posted by zstripe on Tuesday, June 13, 2017 1:36 AM

Whether it be an old thread or not......I find it hard to believe that people have a hard time understanding the instructions for wiring and it also states what the power requirements are further down in the Power Requirements. I have quite a few of the Snap Relays and under-table machines (45) that some have been working for over 32 yr's and I use a dedicated 6amp 18vac transformer to power them with momentary push buttons on control panel and have not had any problems with them what so ever. I got them back when they were 7.00 apiece.

They power the frogs, panel lights and search light signals at 6 cross-overs, which are Tomar 2-light signals.

Take Care! Big Smile

Frank

 

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Posted by Over50 on Saturday, June 17, 2017 2:46 AM

Oops..... Post deleted. Didn't see the original post date was 2004 ... I jumped in because of what I thought was a current thread post. Yet another senior moment ... Oops - Sign

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Posted by gdelmoro on Monday, June 26, 2017 6:19 AM

Anonymous
With an Atlas Snap Relay it's possible to do as many as you want at the same time, or that's what the directions say inside the box. I bought about 6 of those a few years ago & haven't ever figured out how to wire them up. I bought the latest Atlas wiring book about a year ago, but that didn't help either. Now, I have a friend trying out a few on his layout & he's an electronic nut, so, if anyone can figure out the wiring diagram, he's the one. If it's anything more than a simple wiring job I'm confused.Bang Head 

Here you go;

Atlas snap

 

Gary

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Posted by walshrd on Wednesday, June 28, 2017 3:51 PM
Who are you talking to?
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Posted by Redvdub1 on Tuesday, August 01, 2017 8:42 AM

I extensively used Atlas snap (aka latching) relays some 35 years ago to route power and found that they had high failure rates after switching 100 times.  I think it was due to the sliding contact metallurgy (Cu on Cu) used at the time.  Perhaps they have improved the more recent versions ...I don't know.  Hi rel.latching relays (with noble metal switching contacts) are very expensive.

Cap. Discharge machines-I built one 40 years ago that would switch at least12 snap switch machines simultaneously...but I took it out of use due to safety concerns.  Anyone finger shorting the output of that beast would be more than just hurt.  They are easy to build though.  Circuitron has probably put out the most powerful one possible that won't really hurt you (aka kill you) if you finger short it. 

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