Randy,
>>>>with a little patience it should eb not too difficult to see where the missign wire goes.
Yup! I looked more carefully last night and found where the wire goes.
Yeah! It works!
Still, I'd like to review the original plans.
Thanks.
Alan
It's probably almoist the same circuit as Thorne's though. My copy is marked p where I planned to build that - no way I would have etched a pc board either, it would have been point to point wired on a perfboard. Thorne just tookt he opportunity since it was a fairly simple circuit to show how you could buy the kit from Radio Shack and make your own board. I did build the more advanced CD power supply from the book, and I had most of the parts but never built the fancier transisotr throttle - the one with the multiple brake rates and pulse adjust stuff. Actually according to my scribblings in the book I altered it to use the more simple pulse injection from one of the other throttles, and also eliminate the diesel horn portion. I think about that time I aquired a Tech II 1500 and didn't need to roll my own throttle.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hi Alan
I will continue to look. If I can get down to our model railroad club, I am pretty sure the issues is there. Just don't know when. I do remember the perf board though. I had used perf board but never did get the throttle to work like I wanted it to.
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.
Someone will prbably have the article but below is a link to the magazine. I have bought from him.
http://www.railroadtreasures.com/Railroad%20Books/Railroad%20Books%20the%20entire%20list.htm
Search Amazon.com for Practical Electronic Projects for Model Railroaders
Rich,
Thanks for looking.
I had back issues of MR from the late 70's through the late 80's.
I gave them all to a friend when I left my last house around '89.
I do have Practical Electronic Projects for Model Railroaders by Thorne. And there is a transistor
throttle in it, but, it isn't the one I built. This one uses a printed circuit board, way too advanced for
me at the time. Mine was built on what I think was called "perf" board. And it definitely used an SCR.
It also was capable of walk-around tethered hand held controllers.
I really don't have the room to build the layout I had dreamed, so, just looking for a little book shelf kind of thing with some suoer detailed dioramas.
I appreciate any help I can get with this.
There was an SCR throttle in Thorne's "Practical Electronic Projects for Model Railroaders" but good luck getting a copy of that, it's long out of print. There's a bit more complex one here: http://home.cogeco.ca/~rpaisley4/SCRCircuits.html
The principle is the same for all of them, with a little patience it should eb not too difficult to see where the missign wire goes. Or the completely unelectronic method - if a previously sodlered on wire broke off, there will still be a little stub of the wire sodlered to whereever it broke off - use a magnifier to look at all joints and terminals and I;ll bet you can spot where it goes.
From a google search: I think the article is in this book.
Model Railroad Electronics: Basic Concepts to Advanced Projectsn by Peter Thorne
ISBN 0890241465
I did find out the article is in the June 1977 MR. Also, it seems as the device was a MOSFET, not a SCR but still looikg.
I think the SCR throttle might have been by Thorne in the 1970's as I have some articles by him but not the SCR one.
Hansen did some throttle stuff in the 1980's, Symposium on electronics but I did not find the SCR by him.
One person did the TAT 5 but not SCR.
While looking, I had a fantasy idea. Maybe Kalmbach could develop an on line search-able model railroad index. This would help the model railroad community immensely.
Do you have a photo or a little more detaill on what you have?
I remember the article and I will look thought my old back issues as I do remember trying out the circuit many years ago.
Many of the DC 'Super Throttles' from 20-30 years ago hardly work now. If this is an SCR one, you might have a chance finding replacement parts. The old TAT series with transistors, finding a match for leaky transistors is real tough. I suspect this is going to be one of those projects one does just to see if you can get it to work.
I had a pair of the TAT series throttles I built in the late 60's from the MR articles. They worked fine. By the time I built a new permanent layout in 1887, they did not have very much power. Leaky diodes/transistors were the problem. I fixed one, but then bought MRC CM20 walk-arounds on sale. I never bothered to repair the other unit. I took them to several model train flea markets, got a lot of interested looks, but no offers. They went in the trash. There are a lot of good DC throttles out there. Good luck with your 'retro' project.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
There were many articles published with throttle designs in that era. Without a complete index it would be hard to track the several or more SCR designs, and then bounce them against you to see if they struck a memory chord.
Best bet would be to search the Internet for SCR throttles. Look at several circuits, and see if a couple don't come close to your throttle, enough to tell where the broken wires go. Or build a new throttle using your existing components and a present-day circuit as a guide.
my thoughts, your choices
Fred W
I'm attempting to resurrect parts of a layout I had built some thirty years ago.I am trying to make work a transistor throttle I built from plans I think werepublished in Model Railroader. Of course, I can't find the plans.Anyone remember the article and perchance have a copy of it?This was published before the CTC-16 articles.I've found some broken wires and I don't know where they go.Any help would be appreciated.Thanks.Alan