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"Hybrid" Power?

4887 Views 31 Replies 11 Participants Last post by  dbodnar
Has anyone ever installed a large capacitor into a DC track-powered loco along with some circuitry that (a) maintains correct polarity on the cap, and (b) automatically discharges the cap across the main loco power buss (but isolated from the track pickups)  if the track power fails momentarily such as when encountering dirty track, a dead track section, or the problematic frog of some mass-mfrd switches?   A challenge would be to have the circuitry "remember" the track voltage level at the time it dropped and limit the capacitor discharge voltage to that same potential until track power was restored.

The benefit of this over DCC would be no requirement to buy controllers or do any programming to gain smoother performance using traditional track power on electrically less-than-perfect track.
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Posted By toddalin on 02/27/2008 5:31 PM
That would do it Steve.

I would have posted the schematics, but it's Dave's thing and it is on the other site which is pay for view.  I respected both parties by simply alluding to it.  Dave is a regular on this site and I figured that if he wanted it posted, he would post it here. 

Todd

All that I provided was a link to the http://www.trainelectronics.com/ web site that is freely open to anyone with the inclination to enter Dave's name into the search engine of their choice.
2
Posted By SteveC on 02/27/2008 7:02 PM
Posted By toddalin on 02/27/2008 5:31 PM
That would do it Steve.

I would have posted the schematics, but it's Dave's thing and it is on the other site which is pay for view.  I respected both parties by simply alluding to it.  Dave is a regular on this site and I figured that if he wanted it posted, he would post it here. 

Todd

All that I provided was a link to the http://www.trainelectronics.com/ web site that is freely open to anyone with the inclination to enter Dave's name into the search engine of their choice.


Cool!  :cool:  I only remembered it from his original posting two years ago included on the other site.   (See Dave, we do read those. :rolleyes:)

So anyway, anyone who wants to implement "hybrid" power, as per the original thread, there is no need to reinvent the "wheel" because Dave has done the legwork for you.  Now that doesn't mean that the "wheel" can't be improved upon...  /DesktopModules/NTForums/themes/mls/emoticons/whistling.gif

So if this is in fact in the public domain, then we should also include the associated article that describes how to reduce the jack-rabbit starts when power is immediately applied.  Both Dave and I use thermisters although slightly differently. Dave uses larger value (10-20 ohms) to notably make trains accelerate over a period of seconds.  I use low value thermistors (2.5 ohms) to reduce the wear and tear where my trains do automatic stops/starts.  The acceleration is not very noticable, but the intent is to reduce the abuse to the motor and drive train.  At four for a $1 and 6.5 amp capacity, they are cheap protection.



http://www.goldmine-elec-products.com/prodinfo.asp?number=G14789

Maybe others here can find a use for them too.  To find out more, visit Dave's site at:

http://www.trainelectronics.com/artcles/capacitor-thermistor-partII/thermistor.htm
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Gentlemen - the article in question is on my web page (trainelectroincs.com)  Just click on the "Articles" tab at the top.   The article is: Give Your Engines the Capacity to Ignore Ditry Track

There is a companion article, Thermistors, the Magic Behind Smooth Acceleration, that might be of interest as well.

Please let me know if you have any questions.

thanks!

dave
RE: "Hybrid" Power?

Might want to edit that mispelled first link Dave.

By the way, the wireless speedometer car is still running great!

Regards, Greg
Gents - many many thanks for the lively discussion!  For the record, I appreciate Cale's suggestions as they are truly credible options that should be included given my stated caveates.  But it appears that Dave Bodnar has pretty much already "invented this particular wheel" so to speak. Turns out the key issue *is* capacitor size like Bill pointed out initially. Dave B. has suggested a few ways in which to conceal the large caps.  And the safety aspect cannot be overstated. That's why I knew there had to be some diodes and resistors to (a) keep positve and negative polarity correct to the cap's leads at all times and (b) to slow the discharge rate from being instantaneous.  I learned some basic electricicles too,...way back in the 60s and early 70s. 

Al
RE: "Hybrid" Power?

Greg - thanks for the heads- up on the link... fixed!

I appreciate your letting me know that the speedometer car is still alive and well. Speaking of which I am currently (as in they are all over my work bench!) evaluating a new crop of transmitter / receiver pairs that may be able to dramatically extend the range of the unit. One pair claims a range of over 1000 meters! We'll see...

dave
RE: "Hybrid" Power?

Let me know Dave, I'm interested, I often leave the trains running all day, and am at the other side of the house so having the remote display there would be useful.

Regards, Greg
RE: "Hybrid" Power?

A few years back now a friend that works as an EE at a company that re-furbishes subway and passenger cars was telling me about a new generation of "Super-capacitors" that could revolutionize things. Since then I've not heard much. What is your thoughts on these? The safety factors of course are still an issue. Do you think they' be usable in this instance?

Chas
Chas - he was probably referring to "super caps" - they are available but are expensive - LGB uses them with some of its sound systems to keep the sounds operating after the power to the track is off.

I have used ones like this:
www.allelectronics.com/cgi-bin/item/CBC-17/search/1_FARAD_5.5_VOLT_%22#34;SUPER_CAP%22#34;_.html

to keep mirocontrollers working for a time after the power is turned off.

The ones that LGB uses are 10 F (note 10 farads, not microfarads!) at 2.3 volts - they use a string of 4 of them to keep the sound working.

I don't think we are quite at the point where they would keep the motors going for very long.

dave
Greg - I'll let you know how my experiments work out - are you going to the national convention in a few months?  I may have something to show by then.

dave
I'll be there wednesday evening, thurs, and fri morning... hope to see you there, staying in the convention hotel.

Regards, Greg
RE: "Hybrid" Power?

Greg - We'll be there the same nights - I'll be doing workshop Thursday night and we'll likely head back to Pittsburgh Friday morning - let's touch base the week before.

dave
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