On-off switch for digitrax dt402D throttle - advice?

[dccnewbie]

Hi, I'm a newbie here (and to DCC) and saw a reference to installing on-off switches for Digitrax throttles and was wondering if anyone had any tips they could share about installing one. I am just getting set up with my DT402D and I can't believe I have to remove the battery after every use!
I would like to install a switch but my biggest hesitation is damaging the case in getting it open. It seems a bit "reluctant" to crack open, and I think I saw references to damage to the case opening it in some post somewhere. Any hints?
Also, I am figuring I will use a mini toggle switch, but I'm wondering about best placement for it, drilling holes in the case, etc.
Thanks for any advice!

[gmpullman]

Hi dccnewbie, from a newbie (on this forum) myself...

I've been a Digitrax user for more than ten years. I, personally, have never found the need to install an on-off switch in any of my five throttles. The first thing you want to do is get several rechargeable 9v. batteries (I use the Maha Powerex brand. They seem to last longest and maintain higher voltage. There is a brand called Tenergy but I had one fail, the terminal popped off in the first use) The Powerex has gone up in price lately. There's an outfit on Amazon with a charger and three batteries for $60.

Then if you keep your throttle plugged in to the UP5 or UR90 AND have the standby power supplied (wall transformer) it will keep the battery from discharging. See the Digitrax UP5 data sheet. It will not charge the battery but it won't discharge either. If I forget to plug the throttle in after an operating session it is only a matter of seconds to grab a freshly charged battery and swap them out. I have five throttles (2 dt402 and 3 UT4s) and about 9 or 10 batteries.

Someone suggested a little tab of kapton tape on the battery to help extract it from the snug Digitrax battery holder and that is a GOOD suggestion.

Like you, I didn't relish opening the case for the switch installation. Rechargeables are the way to go. Expensive up front but a savings in the long haul. Some of my Powerex batteries are six years old and still working fine. Don't get Energizers, the MaH rating is low and they don't hold a charge very long.

Hope this helps you out... Ed

[dccnewbie]

Thanks. I hadn't really considered that option.

So, I guess leaving the throttle plugged into the UR92 also takes care of the throttle constantly flashing as it "pings" the command station / network?

[Paul Cutler III]

dccnewbie,
I have done a couple dozen of these at my club using the video from Al Mayo on YouTube as a guide. I just went and looked, and the old vid is gone, but he does have one that adds a flashing LED to show that the power is on. A nice option, but I think I'll stick with just the on-off toggle.

I've never broken a throttle. Some are tough to open or close, but a little persuasion with a flat screw driver gets them to pop open. First remove the battery cover, then the 2 screws. The two case halves slide apart (at this time I remove the top plate so it doesn't get lost), then you have to pry the back off the front. Sometimes the screwdriver will come in handy along the sides (there are 3 hooks on each side).

Once open (and Digitrax has said they don't care about that these days), take the top plate and mark where to put the SPST toggle from Radio Shack (the smallest toggle they sell). I also tend to snip off the excess on the zip tie holding the Loconet wire to the throttle board, but do not cut the actual zip tie! Just trim about half the "buckle" part. Drill a hole in the top plate to match the toggle and install it. The toggle should not interfere with the motherboard. Solder two lengths of wire to the toggle.

Next, unsolder one wire from a battery terminal and solder one wire from the toggle in it's plate. Then solder the other wire from the toggle to the loose wire you just removed from the battery terminal. That's the easy part.

Reassembly can be tricky. Several times I've cut a wire snapping the case back together. You have to watch the battery contacts and the wires from the toggle and make sure they don't snag on anything. Tip: put the top plate in last. Just leave it dangling out the top while getting the case back together, then snap it in place later with the back end or handle of a screwdriver.

It's a real simple job. Once I get the tools out, it only takes me 15 min. from start to finish.

[dccnewbie]

Many thanks for the detailed description. I'm off to Radio Shack to pick up my mini toggle switch!

Thanks again.

[railfan4life]

I've been using Digitrax for years and have never bothered to install an on/off switch. I agree that it would be nice if the DT402D just came with one, but it doesn't. I just remove the battery when not in use and keep spare batteries around.

Good luck if you chose to install a switch. Shouldn't be too hard.

Cheers,