Hello,
I want to use slide switches to manually control my turnouts and power the frogs (if it becomes necessary) and I'm racking my brain trying to figure out which switch to use. I've searched and read several articles and looked at YouTube videos that show all kinds of mechanisms to use, but I haven't found the specifications for the switch. I struggle with understaning electricity, but I would think that the switch would need a minimum amp and voltage rating. The inexpensive switches all seem to have amp ratings in the milliamp range, but don't our DCC systems put out several amps?
One switch I was considering is this:
Slide Switch DPDT ON-ON 300mA 30VDC,
It has 4mm of switch travel, so good for throwing an HO turnout. But is 300mA a high enough rating to safely power the frog?
I would not use a slide switch for turnouts unless it is spring loaded. Too muh chance of burning out the turnout coil. Many have done that when using a switch that is not spring return.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
JR Santa Fe,
The switch you list probably should be sufficient, but there won't be much of a "cushion" with some motive power. Don't just look at the current rating. Look at the power rating, which can be calculated by multiplying the current times the volts. In this case the power rating would be 9 watts.
Now divide that by the voltage on the tracks from the DCC system to get total amps the switch will handle at that voltage.
So 9 watts divided by roughly 15 volts (a conservative number since the actual voltage is a bit lower) gives you .6 amps or 600 milliamps.
A few HO locos (especially those with sound) may draw near or a bit over that amount, but since the load through the switch contacts will be transitory (i.e., short-term), it should be fine.
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
Keep in mind that a switch is rated for being operated under load, that is, being turned off and on while a load is present.
If I understand what you want to do, the switch is used to power the frog and maybe use the positive stops the switch has to hold the turnout points in position, the switch won't be operated while a load is present. This give you some leeway with the switch rating.
That said, a short involving the frog, like a derailment, will put the available output current through the switch.
You might consider looking up Electronic Goldmine and enter slide switch in the search bar. They have some more suited to your use I think.
As a first time poster on the Forum your few posts are delayed.Do not use a non momentary switch for solenoid type switch machines, they will burn out the coils.Kinda reading between the lines of your post a DPDT slide switch will control a stall motor type switch machine such as a Tortoise. The Tortoise has a built in DPDT switch for the frog and position indicator.A typical solenoid type switch machine can draw over an amp but only momentarily, continuous voltage to the coil will destroy the solenoid coil and a low current switch. Best to use a CD (capacitor discharge) type power supply for solenoid switch machines. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
I'm not sure we're in agreement on how this is being used. The me, it sounds like there will be no switch machine, and the slide switch itself will push the points over? Is that correct?
What brand and model of turnout? Some actually have plastic frogs and can't be powered. Others have metal frogs, but you would be advised to attach a frog wire before mounting the turnout and threading the wire down through the layout.
It takes an iron man to play with a toy iron horse.
I missed that Mister B, I think you may be correct and in that case the switch he has picked out should work great.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
JR Santa FeBut is 300mA a high enough rating to safely power the frog?
should consider the current when a short occurs.
greg - Philadelphia & Reading / Reading
We tried to set up part of the Scale Rails Of Southwest Florida HO layout using slide swiutches as the throwbar actuators.
It worked great for a couple of years, but later dirt and scenic debris began to get into the slide switches and they became problematic.
I would think a toggle switch with a plastic handle that could be drilled for the throwbar linkage could be better. It might even look more like a switch stand.
I have never seen it done.
-Kevin
Living the dream.
Thanks for the replies and the warm welcome.
I see that I left out a few details (I was trying not to make too long of a post).
The turnouts are Atlas 561 & 562's. The layout will have 26 turnouts. I'm not using Tortoises or anything like that. The cost would be over $400 for those alone, plus electric switches. I'm trying to keep the cost lower and I don't mind manually actuating the turnouts.
Atchee and MisterBeasley (and maybe others) you are correct, the switch is used to keep the points snapped in position (since my Atlas turnouts don't have a snapping feature) and the switch will also power the frog depending on its position. If anyone isn't sure what this looks like, just Google "slide switch for turnout control" and look at the images. But even though I checked a lot of the websites, no specific electrical switches were called out.
And Mister Beasley, I will attach the wire to the frog before installation, I already have the brass screws to solder to. I know it would be a lot harder to try to add the wires later. Thanks for the tip.
Pruitt, thanks for the explanation. That helps.
Given that some suggested that the switch I suggested might be marginal, I checked Electronic Goldmine, as Atchee suggested, and found a toggle switch that is rated at 125 vac and 6 amps. That should be adequate, don't you think? And it costs $1.05 each. It's a DPDT, two positions. Item Number: G1526A
I'll just have to create the linkages to run between the facia and turnout and a mounting bracket. The switch will be underneath the layout.
Does that switch sound like it would be better than the 1st one?
Sorry this is so long. Thanks everybody!
If the OP wants to use the switch to link to the turnout, I do remeber seeing an article in a Model Railroad issue many years ago. Maaybe the issue is still available.
Edit. Here are some ideas from a search.
https://tinyurl.com/yyhzhemf
If you want to go with a higher capacity switch and the throw is longer than the turnout needs you can put a U in the link to make up the difference in the movement.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
I'm not sure how switches are rated, but I would imagine that the numbers quoted are for current and voltage experienced when actually throwing the switch. In this case, the turnout would be unoccupied at this time, so the current would always be zero, and any current experienced should only be after the switch is already in place, not making or breaking contact. Those numbers should be substantially higher.
Hello, and
Years ago I bought about a hundred slide switches from a local electronics surplus shop. I seem to recall the cost was about 12¢ apiece. They were ideal for turnout (HO Shinohara) point control:
Turnout_slide by Edmund, on Flickr
Note the bracket has slotted holes for some adjustment of the side-to-side alignment
IMG_1328 by Edmund, on Flickr
I drilled them, slightly offset, to insert and epoxy the throw wire and control wire into the hefty bakelite handle. I used a copper crimp sleeve to prevent the dowel from splitting.
Since they were DPDT one side could power the frog and the other side for an indicator light and/or signal if needed.
IMG_1314 by Edmund, on Flickr
Back then I was planning to use a dowel-rod/choke cable turnout actuators. I've since converted everything to Tortoises.
IMG_1333 by Edmund, on Flickr
Current rating? Just how much current do you think will be drawn through the frog? At that, only momentarily. Most times the current will be bridged to the other rails, through the wheel pickups, at the frog anyway.
I was more concerned about how much "throw" was available on the slider and how robust the detents were to hold the points. The switch you show in your link has no physical mounting holes. It is made for through-hole PC board solder mounting. Might be difficult to secure to a bracket?
IF I were to buy at Jameco I would look at this switch instead:
https://www.jameco.com/z/35-222-BU-GC-Electronics-DPDT-Slide-Switch-ON-ON-Double-Pole-Double-Throw-Extended-Top-Slide-6A-250VAC_621472.html
But I can not discern from the blurry spec sheet exactly how much throw is available. Many of the offered slide switches these days are miniature or sub-miniature and LOTS of variables among those. Much too small for turnout point throw other than in smaller scales.
Good Luck, Ed
gmpullmanCurrent rating? Just how much current do you think will be drawn through the frog?
Hi Ed, not sure if this was directed towards me or not.
I don't use the auxiliary lever switches on my Tortoises just to power the frog. Since I use the old style Solid-Frog Shinohara turnouts, these are also used for power routing.
So, my A/B/A set of old Athearn PAs will be receiving all their current through those switch contacts once they move past the points.
Certainly, if you were just powering the frog, it would not be necessary.
SeeYou190Hi Ed, not sure if this was directed towards me or not.
Not at all, Kevin. I believe gregc mentioned shorting. If you run DCC and don't have a circuit breaker that will trip before the 300 mA switch melts you really have bigger problems.
An A-B-A set of PAs will have only one wheel at a time on the frog at any given moment. Probably not a huge amount of current will pass through your frog as those engines pass through.
All my turnouts were power-routing Shinoharas when I first built the layout and I did use auxiliary contacts to power the frog. The little bronze strip under the throwbar just wasn't enough to insure good continuity. In this case more rail length than just the frog has to carry current.
Putting the slide switch up top invites debris issues, as Kevin mentioned. Ed's method, with the slide switch UNDER the layout, pretty much solves that.
There are numerous articles on it that have been published over the years, most are variations on what Ed's pictures show. All use simialr size slide switches, and I doublt many have much higher current ratings if it' just for frog power. 99.9% of the time it will be switched when there is no current being drawm through the frog. Unless we're taling massive current, 10's or 100's of times over the switch's ratings, once in a random while toggling the position with a loco stuck on the frog will not damage the switch just that once. Or the next 100 times it happens. Eventually, switchign the contacts with slightly more than the rating will wear the contacts, but if we're talking 1 amp when they cna handle 500ma, it's going to take a LOT - possibly far more operations than the switch is even rated for.
SO if the throw is right, the size of the handle is big enough to allow drilling for the operating rods without splitting it in half - it's a good option.
I did once see an article on using actual houshold light switches. There's only one set of contacts (in a "three way" switch), so if you need contacts for frog power AND signals, they are kind of out.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Either I'm going stark raving mad or it took three days for my response to post (which I understand since I'm a forum newbie). But it means that the people I thanked probably won't see my response since it's back up in the middle of the posts. So thanks again to all who responded. And thanks to GMPullman for posting the pics, that's exactly what I'm talking about. Yes, there are lots of articles about doing this method, but I haven't seen one where they specify which switch to use. Thanks for the switch suggestion. I'm not sure if it has enough travel, though. Most of the time the amount of travel is not specified.
As I mentioned above, I found another switch, this from Electronic Goldmine, as Atchee suggested. This one is rated at 125 vac and 6 amps. Would this be a better choice? And it costs $1.05 each. It's a DPDT, two positions. Item Number: G1526A. Since it's a toggle, the travel isn't critical. I just have to figure out the linkage.
I don't mean to over-analyze but I don't want anything to melt or cause bad performance if the switch is too weak. I hadn't even thought of the damage a short could do until somebody mentioned it.
Thanks again, everybody!
JR Santa Fe Item Number: G1526A. Since it's a toggle, the travel isn't critical. I just have to figure out the linkage.
I think you would become very frustrated trying to use a sub-miniature toggle switch to use for controlling switch points. Any kind of "toggle" switch will have a problem with having TOO MUCH throw as you move farther out from the pivot point.
These are two bucks apiece but include shipping. This is a style you can work with.
JR Santa FeEither I'm going stark raving mad or it took three days for my response to post (which I understand since I'm a forum newbie).
Hang in there, you are almost out of moderation.
Quick... make three responses to other threads and get yourself to instant postings before the weekend!
Welcome aboard!
What Kevin said.
There are people here that have been in moderation for 10 years or more, because, I guess, they don't have much to say.
You get more out of the forum if you give back and try to help people. You will also find out that what you thought you knew, is wrong.
Henry
COB Potomac & Northern
Shenandoah Valley
BigDaddyYou will also find out that what you thought you knew, is wrong.
Oh boy... I have been wrong about so many things...
So true.
Kevin, thanks for the suggestion. Great idea, I think I'm only one post away!
Ed, thanks for finding that switch. I think I'll go with that one. I found a picture of a good setup where the amount of throw doesn't matter because the wire to the turnout uses some mechanical advantage to increase the throw. I'm sure I'll have to experiment with the linkages a little to dial it in, but I don't anticipate it being too difficult.
This is the switch:
This is the setup (2nd photo down from the top):
http://atsf93.qstation.org/blog/?page_id=210
Someday I'll figure out how to post my own pictures.
Thanks again everybody for your suggestions and help!
I think that might be the switch I saw many years ago in a Model railroader magazine article.
You will need a photo hosting site for posting photos. There are some free ones.
I use to use Photo bucket until they locked up my photos and wanted to charge me to release the photos. I deleted all of them. I still have them.