A "Keep Alive" for non-DCC locos

[passenger1955]

A friend of mine has a conventional layout. Lots of track - more than he is capable of keeping clean. Occasionally he gets intermittant loss of power to his locos. There are 2 questions: is there any sort of "Keep Alive" capacitor circuitry that can be placed across the motor leads to help during hesitations?  Second question related question: a third friend of ours is trying to use a train control circuit board to run one of his locos. This board is a non-DCC (BlueRail) which he is operating on a DCC layout. The board does not have a built-in "Keep Alive" connection, and just needs power. If "Keep Alive" type circuitry does exist that could be positioned where the board gets it power, can it be setup so this does not interfere with the DCC on his layout (running other trains). I'm mostly curious about the electronics.

[RR_Mel]

I would say NO.  That would take non polarized super capacitors.  They would be very large as well as expensive.  He would be better off size wise going with a DCC decoder.  I do not have any experience with keep alive, I’ve never had a need to use it.  I keep my track reasonably clean and keep alive isn’t necessary.

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[richg1998]

The "first" DC keep alives where flywheels. Don't know if anyone has come up with an electrical way of doing this.

Someone a couple years ago suggested bi polar caps but those are not storage devices. Electrolytic caps are storage devices but not suitable for DC use.

A Google search will explain how those caps work.

Rich

[rrinker]

 It CAN be done - it's just not as simple as hooking up a capacitor though. If any sort of pulse power is used - chokes (coils) must be used to keep the pulses out of the capacitors - otherwise they will instantly charge up to the pule peak. An arrangement with multiple capacitors and diodes will handle the polarity issue.

 That's the not so good news - as there may not be space for all that. In a loco big enough for all that circuitry, you would be better served by adding additional pickups, ie a steamer that picks up with drivers on both sides PLUS all wheels of the tender. If such a thing stalls out, you have REALLY bad track.

 Now for the bad news. Since DC varies that voltage to control speed, the capacitors will have the least energy exactly when you need it most - when running slow. The energy stored in a capacitor is a product of capacitance and voltage. With the throttle at say 5 volts, the capacitors will only charge to 5 volts. Running near full speed, at 10 volts, the capacitors will charge to 10 volts, and store twice the energy.

Best option may be to make sure there are no sections of track that rely on rail joiners for power - if it's a sectional track layout, solder most of the joints, leaving one plain joiner here and there for expansion and contraction - but make sure there are power feeds on either side of the unsoldered joint. Then, clean the track the RIGHT way - no abrasives (and that includes Brite Boy erasers), no liquids that leave a film behind, and certianly no oil. Clean the wheels too - on the cars as well as locos.  Take a couple of lesser detailed box cars and make masonite slider pads for them. And no smoking in the train room. Unless the layout sits for weeks or months at a time, I think you'll find there will be reliable operation from then on. No more work, really, than fitting all the locos with a DC keep alive circuit, and more effective.

                                  --Randy

 

[rogerhensley]

Might I suggest a track cleaning car of your own choice. I have a similar problem that I solved by running the car ahead of a locomotive around the track. Works fine. That way, the car doesn't have to be a part of a consist.

[gregc]

passenger1955

Second question related question: a third friend of ours is trying to use a train control circuit board to run one of his locos. This board is a non-DCC (BlueRail) which he is operating on a DCC layout.

won't a Bluerail decoder be similar to DCC decoder in that it must rectifiy the voltage on the track to provide a constant voltage to both the decoder and for power to the motor?

wouldn't adding a keep alive to a Bluerail decoder be similar to retrofitting one on a DCC decoder?

[rrinker]

 Since Bluerail canwork on DC, AC, or DCC, I woould have to assume they are built similar to DCC decoders with a bridge rectifier and the same method of applying a keep-alive should work just fine.

                      --Randy

 

[Bayfield Transfer Railway]

It's probably less work to install track wipers.

They used to be quite popular but have gone out of fashion.  I'm not sure why.  I've installed them on engines as small as an Athearn switcher.  They work great.. that engine does NOT stall.  Period.