Tram DCC conversion

[chris]

Haven't made my mind up on whether my tramway will be DC or DCC.

This morning I looked into converting my tram to DCC operation and I could not find anything close to a guide on how to do it. I found a forum entry on how to take the tram apart which was helpful, so I cracked it open and found a clear and well labeled circuit board.

With an old Hornby DCC chip in the spares box I decided to go where apparently no one has gone before and install it. First I wrote my own guide to follow and then got on with it.

It was a two stage process, get the motor wired and then the lights. When I put it on the track I was disappointed to find that rather than 28 or 128 speed steps I had 2, stationary or full speed.

I played around for a while and got a bit of understanding of what was going on, or not going on, but I haven't been able to fix it. I think the problem is with the chip, but it's not easy to diagnose because it's hard wired.

More testing is required.

[george356]

This may be a daft question Chris, but have you had it running on DC before trying to convert it?

[chris]

Not too silly, my DC supply is a 9v PP3 battery, so it had only been tested at one speed!

However once chipped a loco will still run on DC so I have now tested it at 6v, 9v and 12v and it runs fine.

The chip from the spares box had previously been used as a function only decoder so it's the first time it's been used to control a motor. Ive only programmed it in 'opps' mode, I'll pop it on the programming track at some point and see if I can get a better idea of whats going on.

[chris]

I've ordered a few DCC bits an bobs from Bromsgrove Models (who are closing down ) including a small two function decoder. They should arrive tomorrow and I'll have a go at fitting that and see if it works any better than the hornby chip.

[chris]

Looks like my Bromsgrove Models order is lost in the post!

Without an new decoder to try, I popped the tram on my newly created programming track. A thorough investigation of the CVs did through up one odd value, but changing it didn't make a difference, the tram is still binary, full speed or stationary.

While I await a new decoder I may try the Hornby one in an old loco to see how it performs.

[chris]

It was a long wait for the new decoder after the package got lost in the post, but I've replaced the old hornby chip with one for DDC Concepts and a quick test run has proved that the chip was the problem and I now a DCC Tram car.

This afternoon I'll tackle the lights, should be simple. And then I can start to think about the next job for the work bench, putting lights into the second cab of my Voyager.

Broomsgrove Models were very good about the lost package. I would heartily recommend them, if they weren't closing down. You may want to keep an eye on them to see if they do an everything must go sale.

[chris]

Still not actually decided if my tramway will be DCC, but I'm starting to think not.

DCC Concepts decoder is small, but nowhere near as small as the Hornby chip and it won't fit in the small space I'd earmarked for it

Back to the drawing board.

[chris]

Liberated a Hornby decoder from a unit that came "fitted" an replaced it with a better one.

Now time to give the tram car it's third decoder.

[chris]

That should have been a relatively simple conversion to DCC. I had examined the Tram beforehand and written clear instructions on what I wanted to do. When I finally had a working chip that fitted in the space available I followed my instructions, tested every stage and had a working DCC Tram in a little over an hour.

Now the tram is all back together I will take a photo of it next to a loco as requested by Mick and you can all see how they shape up. But that will have to wait till tomorrow, I'm frozen having tidied up the conservatory and packed things away in the shed.