"Hybrid" Power?

RE: "Hybrid" Power?

Understood, Al...

"for those with very limited funds - and there are plenty of them"


Yessir-I am one of those! With 3.5 kids, and I beleive simple battery power is a "dirt cheap improvement" over traditional track power on "electrically less-than-perfect track" for those on ltd budgets.

example: I have a HLW Mack Switcher with 9.6v inside (RC car battery pack) and a DPDT switch for direction...once charged it runs for about 5/6+ hours up/downgrade with consist. One could simply add Del's "Critter Control" for less than $75 and have speed and direction...for a little more they could do the RCS/EVO control with a 2 stick transmitter.

Please don't think I am discounting your idea or trying to steer the discussion away from your original post, rather trying to shed light on the "Cheap" "fixes" that are already avail!-

Good Luck!

cale

RE: "Hybrid" Power?

Gentlemen, Bill Swindell is quite correct. You can think what you will, but capacitors have been around for a long time; they ain't rocket science and very little math is needed to understand them.

What is important is the RC Time Constant: Resistor value multiplied by Capacitor value gives Time in seconds. If a resistor (or resistor equivalent) is placed across a charged capacitor, it discharges to 37 percent of original value in one RC time value.

The RC time constant is in seconds if the capacitor is in farads and resistor is in ohms. So a 1 farad capacitor and a 20 ohm resistor has an RC Time Constant of 20 seconds. And of course if the capacitor value is in microfarads and the resistor value is in megohms, the time constant is still in seconds. And 37 percent of 20 volts is 7.4 volts.

A 1000 microfarrad capacitor and a 20 ohm resistor has a time constant of 0.02 seconds. One half cycle of the AC voltage is 0.0083 seconds long.

A 20 ohm resistor across a 20 volt source draws one amp. So you can approximate the equivalent drain of an engine. And a one farad capacitor is huge.

The inductance of a motor will have an effect on the RC Time Constant, but only if it is high and if there was circuit continuity.

The reason music will last a bit longer is because the circuitry's resistance is high.

Art

Posted By calenelson on 02/27/2008 7:58 AM
Posted By Al McEvoy on 02/27/2008 7:41 AM


 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?  

Hey Al, With a Battery and RC setup all of those above problems would not exist!...just a thought




 
Even after we split power up into distinct sections, the battery people keep propagandizing in non-battery sections.

Please, Cale, respect the people who post here and keep your propaganda in your own sphere. We do not want to have the nonproductive power arguments restarted.

Mark


 

I actually tried what you want to do with an HO streetcar. I wanted an electronic flywheel. I tried hooking capacitors in the range of 1000 mfd across the motor. I saw no change from the motor without the capacitor.

Batteries are a good idea except the really don't like to be discharged to 0 volts.

As for the sound, I just took the electronics out of an LGB locomotive. They have a bank of 10 farad, low voltage capacitors in there. That is how they keep the sound going for a short time after the track power is turned off. Four of thos capacitors inn series would give you 2.5 farads @ 10 volts. You would probably want 16 of these capacitors in series/parallel to give you 2.5 farads @ 20 volts. With that much capacitance, you would probably see some coasting effect on your engine. I never figured out how to handle the reversed polarity when you want to back up.

Posted By Schlosser on 02/27/2008 2:39 PM
Had to learn this stuff back when the Navy got me in 1945, jimtyp; I think it's easier to learn when you're young. Neither batteries or large capacitors come in 'AC', so backing up presents an additional problem. This can be solved by rectifiers but the hazards of exploding capacitors - or batteries - are really not good.

While working for IBM back in the 50's, I had the end covers off a big power supply, larger that a side-by-side freezer/refrigerator, when one in a bunch of capacitors blew. Fortunately, the plastic shield held; I just aged a few months. These 'safety-covers' had just been recently installed as several employees had been injured by exploding caps.

Art


First mainframe computer I worked on had several 48V 5000 uF electrolytic capacitors in it (6" long, 3" diameter). One of the first test steps was to get on a ladder to physically look at them to verify they were installed correctly (little molded in "+" sign on the "right" bus bar).  

Measuring them with a VOM was iffy at best.  Sometimes you just could not tell which pole was the positive, especially because there were so many in parallel on the power bus bars

One day. Day shift claimed to have verified a new computer chassis and yet one "blew" when they applied power.  The guy was in big trouble for allegedly "not checking".

When I came in for Night shift I was admonished THREE times (my Shift Foreman, the Department Supervisor and THE Corporate Director of Safety) to be sure I checked them.  I DID, under the supervision of the foreman, even!  BUT... Mine sounded like a cherry bomb in a trashcan when it went!  Blew brown/black sticky foil and paper all over the place!  I pulled a dozen caps from stock and found the manufacturer had assembled about 1/2 of them with the end plate 180-deg out, which could not have been easy since the connections inside were not symmetrical.


As to the question here.  A cap could hold power for a sound card or a low current lamp for very minor power interruptions, but not a power hog like a motor.  This would require a high current capacity battery and if you are going that far, get rid of the track power and just run from the battery.  Or go Live Steam and forget electricity all together!