Neat throttle

[mmagliaro]

The DC compensation feature in the Heathkit throttle is supposed to compensate for increased motor loads of "longer duration" (however long that is) and increase the output voltage to reduce, but not eliminate slowing of the engine on hills or curves.  The idea is that although it is normal for a train to slow down when it climbs a grade, our model trains slow down too much, so a compensation circuit is needed to mitigate this.

The AC compensation is supposed to compensate for "brief" or "instantaneous" fluctuations in motor load (i.e. rod binds, mechanism friction etc) to even out the speed of the motor.

Both of these features have a trimmer pot on the Heathkit control how aggressively they attempt to compensate for these load variations.

And remember, the Heathkit Throttle is actually a Linn Westcott TAT V in another cabinet.  So if anyone can find detailed discussions of the Westcott throttle that explain what these compensation circuits actually do, that would be very interesting.   I don't have the old MR issues where his articles appeared.

[ednadolski]

It strikes me that this product may be perfect for flat layouts but if you have any grades it would lose a lot of verisimilitude.  That is, unless there's some complicated system for telling the throttle what the grade is and changing the relationship of speed to throttle notch accordingly.  I was actually thinking about this the other day and thinking that if the user had a way of telling the throttle what the grade is, it could all be made to work.

(LOL, had to go look up that fancy 'v' word...  )

This dude built his own control stand, which has a counter in the upper right hand corner that is supposed to tell the throttle how many cars are in the train, so it can adjust the 'momentum' on the fly:

I guess if you're a hopelessly dedicated  and counters aren't your thing, you can always try adding a strain gauge to the drawbars, and program the decoder to behave according to how much actual 'tonnage' the engine is pulling or pushing:

https://en.wikipedia.org/wiki/Strain_gauge


Ed

[peteski]

This is probably 'way out in left field, but here goes...

Last year off eBay I purchased a Heathkit "Electronic Throttle", which is as far from the subject being discussed here as you can get. It's big, heavy (think 1970s era stereo amplifiers), and it has a feature called a "DC Compensation", which reads the current and allows for the engine to slow slightly as it climbs an incline. Is this similar to what you're talking about?

I should mention it also has "AC Compensation", which I guess allows for variations in side-rod binding, etc.

I think Max mentioned that this is basically a TAT V throttle (which I also own, built from an article in MR Magazine). I'm not quite sure if the compensation works quite like you are describing.  I have to find the article because it explains how the compensation works.

However, regardless of how the DC throttle works, the throttle in this thread is DCC. Contemporary DCC decoders do not provide any type of a speed or motor load feedback back to the command station or to the throttle.

[strummer]

However, regardless of how the DC throttle works, the throttle in this thread is DCC. Contemporary DCC decoders do not provide any type of a speed or motor load feedback back to the command station or to the throttle.

Oops...sorry Peteski!

Mark in Oregon

[ednadolski]

new vid on this:

[James Costello]

Thanks Ed - neat video.

[u18b]

I'm impressed with the concept over all.
A lot of positives for me here.

But having watched the vid..... here's some turnoffs.

1.  Disassembly to change/charge batteries???  Yikes.  Not only is this inconvenient (compared to some kind of trap door) but are you not risking frying something with electrostatic discharge?  Or how about a wedding ring that touches exactly the wrong spot.

My MRC Prodigy Wireless handheld controller uses four AAA rechargeable batteries.   It has a trap door to get to them (no disassembly) and you can charge the batteries with them INSIDE the unit by plugging in the Cat5 cable to the base unit.

The proto throttle needs to do something like that.

2.  Yikes!!!!  All those button pushes just to set a locomotive number??   Reminds me of my first DCC system- the Atlas Master system.  This is a Lenz bottom tier system.  Don't get me wrong.  I loved it for the 50 bucks I paid for it to get me into DCC.  Atlas did a great job getting me in the door of DCC. But I love the Prodigy system better partially because of the numeric keys.

Which brings up a philosophical issue with the proto throttle. 

We want it to LOOK and function like the real thing..... but there are already and MUST be some compromises to make it functional with DCC (a few extra buttons, LCD screen, etc).

If you're going to make compromises..... why not make one more.  Add a full keypad on top to make inputting info less of a frustration.

I could be wrong.... but my gut tells me I would get frustrated over time with all those inputs.

Overall, I like the concept.
But I see it as still in its infancy period.

It will be interesting to see how it develops over time.
Just my 2 cents.

[Ken Ford]

I’m very interested in this for a limited purpose - switching.  Locomotive changes would be infrequent, so programming wouldn’t be a problem.  But I have to agree with Ron about the need to disassemble the case to change batteries - I would probably change out the Phillips heads for knurled knobs.

Also, the case looks to be as deep as it is because of the battery tray location.  Would it be possible to make the throttle slightly taller to move the batteries to an end, slim the case and add a battery trap door instead?

[mmagliaro]

Not even being a DCC guy... but one thing I never liked about a lot of handsets I've used is that they just have too
many darn buttons.   The pushbutton scroll up/down thing to set the decoder number is ugly, I admit.  But I'm not
a fan of the keypad either because even though it's easy, it puts 10 more buttons on the throttle.

What about a simple dial rotary encoder?  You still have an LCD display.  You just spin the dial left or right to
run the number up or down to what you want, and then push a button.   Controls like that are usually speed sensitive,
so if you spin the dial faster, the number rolls up faster.  Now, you only have one control instead of 10 buttons.

Do any DCC throttles work that way?

[peteski]

Not even being a DCC guy... but one thing I never liked about a lot of handsets I've used is that they just have too
many darn buttons.   The pushbutton scroll up/down thing to set the decoder number is ugly, I admit.  But I'm not
a fan of the keypad either because even though it's easy, it puts 10 more buttons on the throttle.

What about a simple dial rotary encoder?  You still have an LCD display.  You just spin the dial left or right to
run the number up or down to what you want, and then push a button.   Controls like that are usually speed sensitive,
so if you spin the dial faster, the number rolls up faster.  Now, you only have one control instead of 10 buttons.

Do any DCC throttles work that way?

Yes, Digitrax full-function throttles have continuous-spinning digital encoders which are used for speed control and also for setting the address (if you feel like twirling instead of using the keypad).  The Digitrax utility throttle has 4 (0-9) dials/knobs  to dialing the decoder address. No display since the dials shows the number they are dialed to.  But since sound decoders use bunch of functions, a numeric keypad is quite desired (since it also activates DCC functions 0-9)  Even more buttons woudl be handy since sound decoders often have more than 10 functions (light and sound effects).

[delamaize]

Personally, I think this throttle would be a fun way to control a small switching layout, something where the operator doesn't move around a lot. As a mobile throttle, it seems a little too busy.

[mu26aeh]

Here is an ops video from the same guy on the Seaboard Central