First of all, thanks for this resource.

I am in the process of adding air control to my garden railroad turnouts. I am already running a Digitrax Chief system. Being in the Silicon Valley, I have managed to procure surplus 12 VDC pnuematic soleniods at a good price. My question is, what is the best way to interface the solenoids? I already have a couple of DS54 decoders, but will probably need a couple more. It is not clear in all the instructions etc., the proper way to control something like a DC solenoid or Relay. Everything is geared towards stall motors or snap switches, or the LGB switch machines, which I have found to be subject to the weather (mainly sprinklers)

In addition, what other stationary decoders might be suitable for this application?

Thanks,

Scott

-- Scott Foster (scott.l.foster@seagate.com), May 17, 2004

Answers

If you have already procured your valves, then you have the expensive part taken care of.

I do suggest that you use DS-54's to control your valves. I tried using DS-44's but found that they simply cannot take high ambient temperatures. When it gets above 90 degrees, they quit working. I don't have any problems with the DS-54's taking our Texas summers.

There are probably a few ways you can go about this. Now that there is someone besides myself trying to do this, maybe I will document what I did on my web page one of these days.

I don't have the time to do so now. So this brief, written description will have to do for now.

I made a little circuit board that uses the Radio Shack "highly sensitive" relay between the common out of a DS-54 jack and EITHER (it doesn't matter) of it's turnout control outputs. Essentially, you wire it up like half of a twin-coil machine.

I then use the relay to route 12V, from a separate power supply, to operate the valve. Apply the 12V to the wiper of the relay. Then connect whichever contact of the relay that makes your valve activate the way you want it to.

Be sure you have read my web page for some other tips on using Del- Aire in the garden. http://www.WiringForDCC.com/garden.htm

I was just thinking the other day that my Del-Aire has been in the garden now going on three years. I have had no problems from any of the Del-Aire equipment. The only problem I have had are with the brass 1/4" tubing to 1/8" adapters I created. During the hot summers, the tubing gets soft and the brass adapters I created popped off. A little Walthers Goo took care of that problem.

-- Allan Gartner (wire4dcc_admin@comcast.net), May 17, 2004.

You can use Digikey part no. Z747-ND It is a 12V, 44mA relay, 272 ohm relay. (see my Parts page http://www.wiringfordcc.com/parts.htm) Of course, if you find one that has an even higher resistance, you can use it. The Digikey relay may be cheaper than from Radio Shack. From Radio Shack, you should be able to use 275-248 or 275- 249.

If you have enough, the 740 ohm coil relays that you have should be excellent.

-- Allan Gartner (wire4dcc_admin@comcast.net), May 18, 2004.

Allan,

Thanks for the help. I had already read your article about Del Aire in the garden, and that was why I posted my question here. Luckily, I do not have to put up with too many days over 90 deg. in the SF Bay Area, so I do not have the heat issues you do.

I was planning on going the separate relay method. I looked at the Radio Shack for "highly sensative" relay and could not find one labeled as such. Do you know the coil voltage and resistance. I already have some with a 12 VDC, 740 ohm coil.

Except for the heat issue, would the DS44 work in this application?

Thank You,

Scott

-- Scott Foster (scott.l.foster@seagate.com), May 18, 2004.