Talking T Gauge

Chris333 · Joined: 25 Sep 2008 Posts: 74

The 1.73VDC goes down to 1.72-1.71VDC when the trim is turned down.

pray59 · Joined: 05 Sep 2008 Posts: 88 Location: Fremont, CA

Well, that controller beats me too! I don't understand why it won't work like the one Armand built.
_________________
-Robert Ray

Jax · Joined: 04 Dec 2008 Posts: 44 Location: London, UK

Perhaps he didn't quite give you the correct schematic.

And don't ask me, I'm an old fashioned gal and didn't do anything like electronics at grammar (cookery, needlework, yes). Don't understand it at all. Confused

kingbf · Joined: 26 Dec 2008 Posts: 1

Thought this schematic for a PWM motor control might prove interesting. Haven't built or tested it, but it looks promising.
kingbf

www.uoguelph.ca/~antoon/circ/circuits.htm

go to - Pulse Width modulator, CD4093

Chris333 · Joined: 25 Sep 2008 Posts: 74

I'll wait for someone else to test this one first. Surprised

rmyers · Joined: 19 Nov 2008 Posts: 73 Location: Evanston, IL USA

I was browsing for a suitable pulse width circuit and came across this simple one: http://www.eleinmec.com/article.asp?28.

British source so part numbers for British supplier, but simple enough to translate for other countries. 3-15 v. input so we should be able to do 4.5 or 5 v. for T. 3 a. maximum current so no problem there.

Uses a pair of 555s to get the wave form and a TIP131C as the power transistor.

Where the motor is shown on the schematic, remove the motor and put in a dpdt for direction control and the track power outputs.

Bob

AndyA · Joined: 21 Oct 2008 Posts: 33 Location: Southampton, UK

I'm having a couple of problems with that link. First, although I can see the "shopping list", there's an error message at the top saying that the article text is missing. Second I can't see the circuit diagram, although a fairly familiar looking schematic popped up in a little box when I moused over th 555 timer in the list.

Any ideas?

regards
Andy A

rmyers · Joined: 19 Nov 2008 Posts: 73 Location: Evanston, IL USA

AndyA · Joined: 21 Oct 2008 Posts: 33 Location: Southampton, UK

Okay, I'm also using the latest Firefox, but it turns out that's not the problem. Your Google search terms turn up the thing no problem, article and all including schematic.

Clicking on your link gives the shopping list but no supporting text. I'm guessing that it's the trailing '.', but I would have expected a wrong link to just give a 404. I guess one part of their database is stripping the '.' from the article parameter, the other not. C'est la vie.

thanks for your help. The circuit looks good and should truly work at dead stop even with the low voltage output, but I have no trains to check whether it will creep. However, the same problem will occur as with an earlier one posted here - if it works first time out, great, if not, it'll most likely take a 'scope to trace the fault, unless it's just a joint and can be found by inspection.

I'm going to have a look at

EDIT: looks as if the upload was truncated.

I'm going to look at their other suggested solution of using a computer (USB) output. This would have the advantage that if the software works on one USB machine running a given OS, it "should" work on all. Smile

But to get back to the original topic, nice find in that circuit.

regards
Andy A

rmyers · Joined: 19 Nov 2008 Posts: 73 Location: Evanston, IL USA

The link should be: http://www.eleinmec.com/article.asp?28
I was trying to be grammatical and ended the sentence with a full stop -- which the link creator thinks to be part of the link.

Sorry, Bob