Not model RRing, but impressive modeling

Rick Jones wrote:
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This may get someone "Off the Dime" so to speak. Because doing this would a fairly 'trivial' thing 'electronically speaking'.
Chuck D.

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Um, this is already out there with QSI sound decoders. If you set your deceleration momentum (CV04) to a high level, the loco will "coast" for a long, long time. To stop the train, you must first reduce the throttle to zero and wait until the diesel/steam sounds goes into idle. Then you press and release F7, and one will hear an air release sound (which is supposed to be from the brake stand in the cab). The train "brakes" come on, and the train will slow at an increasing rate unless you "lap" the brake by pressing and releasing F7 again (the air release sound stops, but the train will continue to slow at that rate and no faster). One can accelerate and cancel out the brakes by merely moving the throttle above zero percent, or the train will come to a halt...eventually. Or, one can hit the emergency brake on the throttle and stop ASAP (w/ flywheels only). I've done this many times with my Atlas Trainmaster. I also status edit the address for 14 speed steps, while also boosting the starting momentum (CV03). This can get interesting, as you can use the push buttons on the throttle to go in 7% jumps, which is kinda like the notches on a real loco. The momentum smoothes out the speed steps, and the brakes do the same. It's a bit of a challenge, but fun at the same time.
Paul A. Cutler III ************* Weather Or No Go New Haven *************

Pac Man wrote:
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This sounds like a small step in the right direction, but still not as authentic as what could be done. Let's hope someone continues to evolve the idea into something more in line with the TAT-IV capabilities.

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About the only thing I can think of that isn't "real" enough is that you can't apply the brakes while the throttle is above 00%. What else do you want it to do? Oh, and what's a TAT-IV? I've used PSI throttles in the past (my club used them) which had momentum, service brakes, etc. Is the TAT-IV like that?
Paul A. Cutler III ************* Weather Or No Go New Haven *************

Pac Man wrote:
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The TAT-IV (True Action Throttle Version 4) was developed by Linn Wescott. An article on constructing one appeared in the 3/69 MR. As I mentioned previously, braking was applied separately with a brake handle with several positions that replicated those of an actual locomotive brake stand. The original was a large, fascia mounted unit, but I think a handheld controller with a throttle knob and brake handle with multiple positions could be manufactured. Unfortunately I can't find a really good article about it online, just some minor references.

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The TAT-IV offered controllable rate acceleration, adjustable starting voltage, pulse power with adjustable pulse width and frequency square wave pulses that automatically diminished as the filtered DC main power increased, and a five position brake (run-release-service-quick service-emergency). It was great for realistic operation, and for overcoming the shortcomings of open-frame motors.
A version of the TAT-IV throttle was offered for several years as a HeathKit - the RP-1065. Heath offered a remote - the RPA-1065-1, but it used a heavy 12 conductor cable so that only a CA or ex-MN governor would not tire holding it through an entire op session. I made a simple mod to mine that sacrificed the 5 position remote brake switch and the throttle pot, and made a remote with accelerate and decelerate buttons mounted in a used vitamin container that worked with a lighter 4-conductor cord. Geezer

On 5/5/2008 7:17 PM Geezer spake thus:
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You don't happen to have a circuit diagram (or a link to one) that you can post, do you? I'm curious how this ancient piece of linear (i.e., non-digital, non-switching) electronic equipment worked.

On 5/13/2008 12:00 PM David Nebenzahl spake thus:
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Hmm; looks like a guy would want to get a copy of the March 1969 issue of /Model Railroader/. Anyone happen to have one handy?

David Nebenzahl wrote:
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I have the magazine, but lack a scanner. The article and schematics are spread over multiple pages.

Pac Man wrote:
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Yes, with separate throttle and brake controls. The brake handle has multiple positions similar to a prototype brake stand on a locomotive. A pushbutton to apply brakes just isn't the same IMHO.

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It is when your operating with walk around throttles, switching industries and handling car-cards and waybills at the same time.
-- Cheers
Roger T. Home of the Great Eastern Railway at:- http://www.highspeedplus.com/~rogertra / Latitude: 48° 25' North Longitude: 123° 21' West

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Ok, so it's more the interface you're looking for. One can get realistic results these days with DCC and air braking, but the interface is not up to prototype standards by any means. Hmm... I'm thinking something like the Digitrax DT400 throttle, but with the second cab encoder knob replaced with a brake handle. Maybe replace the other throttle with an 10-position rotary switch that would emulate the 8 throttle notches, plus Idle and Off. Hmm...
BTW, that is one baaad sig you got there. :-)
Paul A. Cutler III ************* "The Internet is like a herd of performing elephants with diarrhea ---- massive, difficult to redirect, awe-inspiring, entertaining, and a source of mind-boggling amounts of excrement when you least expect it." - Anon. *************

Pac Man wrote:
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Well, the interface coupled with the functionality. The thing that intrigues me is rooted in a description an author gave of using a transistorized throttle on Whit Towers's Alturas & Lone Pine. The article was in MR in the late '60s I believe. To lazy to dig and find the exact year and month ATM. In the article he described having to bring his train into a siding for a meet. The train was nearly as long as the siding IIRC, so he had little room for error. Don't apply enough brakes and you overshoot the siding in front of the opposing train; too much brakes and you won't clear the end of the train or possibly wind up with some (virtual) flat wheels. Anyone playing MS Train Simulator knows the feeling of stopping short or overshooting the correct position for taking on water from the tank or spout while manipulating the brake handle. That's the realism I want in a DCC throttle.

John Fraser wrote:
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The model train problem is more one of friction than mass. Our bearings have proportionately more stiction and friction than the real ones. In particular, overcoming stiction is far greater than for the prototype, so our trains leap from zero to an unrealistic speed very quickly. If you add momentum effect to your controller then scale speeds mixed with foreshortened tracks is quite taxing to operate.
Greg.P.