Looking for plans for transistorized throttle project from MR

[OldEastRR]

Thanks, Peteski. This guy was an electronics/electrical whiz who built and maintained electrical systems for heavy duty industrial use, so he tended to go heavy on equipment. Thus the relay. The SPST on the hand-held throttle turned the relay on and off and THAT determined the polarity. Why not just a DPDT? "Well, where's the fun in THAT?" he probably said.

[mmagliaro]

There  is a charming old book entitled "Practical Electronic Projects for Model Railroaders" by Peter Thorne, from 1974.
(well, okay, at least I think it's charming).
It has several transistor throttle circuits in it, including a simple hand-held thing like you are describing that is powered off the terminals of any old power pack you have lying around.  Used copies of the book pop up on eBay all the time.

Thorne does a good job of explaining components and electronics construction technique, in addition to presenting the circuits so that anybody with basic soldering ability can build them.  He includes a lot of drawings and diagrams.   Although the circuits are old, everything in the book is made from very bread-and-butter components and it's easy to find modern-day equivalent components.

[Mark5]

@DKS used to have nice throttle laid out, but the link is dead.

https://www.therailwire.net/forum/index.php?topic=44461.0

Mark

[Missaberoad]

@DKS used to have nice throttle laid out, but the link is dead.

https://www.therailwire.net/forum/index.php?topic=44461.0

Mark

http://davidksmith.com/modeling/projects/throttle.htm

[MarkInLA]

~ Does no one identify with my post #13 ? I mean, am I, can I be the only one here who built, or at least read the article on how to build it, in the 1950s, you old hoggers out there, like me !!? Twas maybe 1957...
I remember my white on black schematic on the small Masonite panel I made of my 4X8, block-toggled snap track pike, 1st layout, with the short pot-stem I'd attached a knob to and whatever else it included (Was it that momentum intensity was fixed, and pot was interim throttle, by-passing MRC power-pack's ? Not too clear any longer).
It'd just be nice to know I didn't dream it all, that someone out there 'went there', too, oh so very long ago ! Dig ? ~   

[peteski]

~ Does no one identify with my post #13 ? I mean, am I, can I be the only one here who built, or at least read the article on how to build it, in the 1950s, you old hoggers out there, like me !!? Twas maybe 1957...
 

1957?  That was few years before I even existed.  It was even before my parents got married. 

I did build a throttle from a project featured in the Model Railroader. But it was either late '80s or early '90s.  It was the TAT V throttle.  I stuffed it in a MRC case.





I still have it and use it occasionally.

[Tom L]

So, do you think you could use this as a wireless DC throttle? Sorry, couldn’t seem to post a direct link, but here’s a screen shot. 

Edit:  no reverse with remote, never mind!

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Tom L
Wellington

[MarkInLA]

Nice job there, Peteski !!
Couldn't do dat in 50s with those metal, gold, MRCs, then. Plus the larger components: big 'top-hat' 3 leg transistors, big caps, and such.
Geesh, I wish someone out there did the 50s one, too. Maybe they still have it !!!
Thanks

[mmagliaro]

How much current does a voltmeter draw?
Should the output voltage from a rheostat based power pack be different when observing the output voltage with a meter alone as compared to when a loco/motor is also connected to it?

It will be different when the loco is connected because the load from the loco will cause a voltage drop through the rheostat.

But the meter itself, even a simple cheap analog voltmeter, has a high enough impedance that it's not going to ever draw enough current to affect a rheostat power pack circuit.  A good analog meter is usually something like 50,000 ohms/volt, and digital meters can be much higher than that.