Great article on Stayin' Alive!

That Bee Gees tune is going though my head as I type this...what a great, thorough summary of recent trends in capacitors and super-capacitors. I recently tried out a few TCS KA2 Keep Alive modules with a few favorite steam locos that were notorious for dropping out (including the 2-6-0 featured in my signature graphic below). They function perfectly with my TSU-750 decoders, and it is like having a completely different locomotive. I also tried a KAM-4 with onboard Keep Alive in a small 4-wheeled industrial loco, and it runs smooth and silent. Amazing stuff. Now I know the full story behind what I have been dabbling in!

Thanks, Bruce, I always learn new things reading your columns!

Thanks, Verne

Love to hear your option

I'm pretty well known . . .

What value of resistor

Bruce,

Thanks for the great information.  I always look forward to your articles and this one is especially helpful and the timing is perfect.  BTW I have a Bachmann Percy with a newly installed KAT22 inside the cab and it is a MUCH better performer.

A question concerning the Hybrid circuit you mentioned.  I have a wireless camera which operates at 9v powered by a battery eliminator circuit using an LM317 voltage regulator because 9v batteries only last about 45 minutes.  But it now has intermittent signal issues.  I am planning to add a 9v NiMH battery rated at 170mAh in parallel.  I did look at Stan Ames' website but am uncertain of the correct value for the resistor.  What value resistor would you recommend?

Thanks again,

Dave

Glad to hear of your success

Keep alive article question

I haven't read the issue yet but would like to know if your article addresses ESU Loksound keep alive possibilities?  Most of my roster is so equipped; only two OEM Bachmann Soundtraxx locos.

Regards,

Scott Groff

Awesome!

The article discusses how to

ESU V4.0

It depends on which decoder you have.  If you have any decoders before version 4.0 (V3.0, or V3.5), they are not designed for keep alive modules, but the V4.0s are all designed for it.  I would personally like to know if a Loksound V4.0 can use a TCS power module instead of an ESU unit.

Thanks, Jurgen, for some first-hand input.

What speed?

I'm a little confused about one aspect of the keep-alive capacitors.  As I understand it, they are functionally the same as providing full voltage DC on the rails (as far as the decoder knows), which would mean that the decoder would take off at full speed if it loses the DCC signal.  Is that correct?  Or is there something else going on, and the decoder knows to keep running at the same speed it was?

What speed?

The decoder will continue to operate at the same speed it was going when the signal was lost.  When it runs out of cap charge, it will come to a stop.

Ken

The decoder still controls the locomotive - it only responds to DCC signals, so if the DCC signal is lost, it just keeps doing whatever it was last told to do and won't get some new instruction to take off.

DCC Staying alive

Thanks for the heads up Bruce re: stay alive decoder crud jumper.

cheers

Ros

Thanks for the insights

Another excellent column. I will be buying a Keepalive and then will try adding a capacitor to other soundtraxx Tsunami decoders with only a single cap...Keep up the great work you are doing to  advance the Dcc aspect of the Hobby...Joe

RC circuits

Thanks Bruce for another great article, continuing on in your endevour to educate the masses.

I kept looking for the paragraph to explain RC circuits and the equivalent values of resistors and 

capacitors in series or parallel.

Keep up the excellent work, Cheers, Vern

The competition is heating up . .

since I wrote this.

Mark Gurries has posted a comparison chart with many different units on it. Check out:  https://sites.google.com/site/markgurries/home/decoders/keep-alive-compatibility

Bruce...Railpro decoders

I have sold off all my DCC decoders and installing Railpro decoders. No problem with the installation and one problem is adding the keep alive capacitor to the Railpro sealed decoder. Suggestions on where to tie in the capacitor leads or KA 1/2 for a Railpro decoder?

Carter

Keep alives and RailPro

Carter,

Visit the Railpro Users Group at https://rpug.pdc.ca/ and specifically the post https://rpug.pdc.ca/index.php/topic,383.0.html

I've done this. It works.

Keep alives and RailPro

There are also instructions (PDF) at the bottom of my RailPro Accessories page for installing TCS Keep Alives with LM-2 and LM-3 series RailPro modules.

http://pdc.ca/rr/catalog/product/wiring-harnesses-keep-alives-and-other-accessories/63

I do this in all of my locomotives as well. they are great!

Cheers!

Keep Alive to Avoid Wiring all the Frogs

I'll have to read this article and see if I can 'absorb' it (electronically challenged).

i had hopes that good 'keep alive' would allow me to use my many 'insulfrog'  Pecos without modifying them all.