Insulated Rail Relay Based Sensor

I think that's a good idea. I don't recall seeing much (or anything) like this for 3 rail. I do think it would fill a need and would be worth a try. Of course, if you posted the gerber files and parts list I would certainly try this one myself at the inexpensive PCB maker you found (forgot the name).    It just might be too good of an idea to do that with though.

We are discussing the IR detectors in another thread (ITADs and Making Your Own) and the IR devices are, so far, having some problems, but more things to try are in the works. Your input is welcome, BTW, if you haven't been there already. 

John

If your looking for feedback I think this is a great idea and would buy these if you bring them to market.

Bill

Nice design, I would be interested in a few.

I would be interested.

Dear John

Nice simple design. What would the manufacture (you) suggest retail price for one of these?

John

Looks like another winner. I have been using the SPDT version based on input from you and Stan 2004  in the past with no problems. I have also been looking at A DPDT version using the same relay with terminal boards for ease of connection as shown above. I'm sure this will go over big wheather it be in kit form or completely assembled for those who are adverse to assembly and soldering.

Gerry

I have a couple of prototype PCB's coming, and I am trying to line up cheap components.  Note that I used all thru-hole stuff as that's typically easier to get cheaply and also makes it easy to build.  Maybe there'll be some low cost kits in the future.   It's a basic circuit, and one I've been using on our club layout hand building them.  I figured I'd like to have about 15 of these myself to replace the hodgepodge of stuff we use.  I did find some nice terminal blocks for a very good price and ordered a bunch of them.  I know I can use them somewhere if not here.

I'd like it to be cheap, in the $10 range, depending on the component costs.

Hey John,

You know more about the relay you are using than I do so I will just ask......

Do you think there is a need for a northbound diode across the coil?

Lou N

That thought crossed my mind, but I've been using this relay in a similar lashup for a long time with no ill effects.  It has a 15ma coil, so any kickback seems to get lost in the cap.  I've had them running several years running signals, still running.

In the off chance that it should prove to be an issue, I left provisions for an SMT diode at D2 on the left.

So will this trigger an MTH per signal bridge?

You get relay contact closures when something is on the insulated rail with bounce protection.  If you can trigger it with something like the MTH ITAD, you can trigger it with this board.

prrhorseshoecurve posted:

So will this trigger an MTH per signal bridge?

If it does count me in for a bunch!

Hi John - Great looking easy circuit - I'd be in for a couple.

I'd be interested in some too!

gunrunnerjohn posted:

That thought crossed my mind, but I've been using this relay in a similar lashup for a long time with no ill effects.  It has a 15ma coil, so any kickback seems to get lost in the cap.  I've had them running several years running signals, still running.

Thanks John. Perfect timing. I had a call today from a friend asking about IR devices and I said there were better ways. Will look forward to your new product introduction.

Lou N 

I would be a buyer too !!!!   come on John what are you waiting for !!! lol Let's go, they should be packaged and ready to go !!

Alex

Well, I have to get some parts in and actually assemble a few for final tests.  Since it's a circuit that I've been using, I really just want to see the boards and make sure the components like the terminal strips and the like actually fit with the current layout.  I've been burned too many times buying a bunch of boards, only to find out I made some spacing error!

Lou, see previous post, I added a SMT diode on the end in case for any reason I deem the diode should be there.  I didn't want to make the board any larger for the full sized diode.

I would definitely take some too. Kinda what I was getting at at my earlier post referring to the gerber files and trying it myself. Assembled, kits, boards with parts list, any way is fine with me. I do like the idea of the through hole components for the kits though, I think many other will too. But I do need to try that SMT stuff one of these days.

Also, I still haven't forgotten trying the Watchdog devices. I'm still missing some parts for the layout changes I want to make. If I don't get them pretty soon I will go ahead and try them and rework things later on.