Easy DIY DCC keep alive (19) 

Would still be greatly helpful to provide that schematic and a Bill of Material within this presentation since this is where we are viewing. Very useful video - thanks for posting!

@@2011Maynard I agree, i do not have this issue seems easy to post schematic, but what do i know

I got all my parts exactly where you said they would be. I was just wondering, because the diode is 1A fast recovery, fast recovery just means it’s a better diode ,right?

Brilliant, I love it when folks break the mold so to speak and come up with solutions like this!

Glad to hear it worked for you. Now I just wish I could find those really small capacitors that TCS uses in their new Keep Alives.

I suggest you watch video 31 and read the description to it where I provide a list of the components and where to get them.

These really aren’t capable,of being downsized as the super capacitors are not available in a smaller size to my knowledge. The only success I’ve had with installing keep alives in an N-scale loco was in the tender of steam loco. In that case it was a long haul tender so plenty of room for a TCS KA1 if I remember correctly.

@@TheDCCGuy okay, thank you. I am modeling the the Camas Prairie RR in the mid 70's so steam is not really an option.

You really need a stay alive device to do the job since the Sound Car is essentially a decoder without the mobile functions. If the Current Keeper is too big for you then one of the small TCS Keep Alive devices will work too. Take a look at my video on making the connection for stay alives to get the wires right.

Duncan, welcome to the channel, do you model UK prototypes and if so what time frame? Take a look at video 31 for more info on these circuits and the component list is in the description for that video. I also am planning an updated video on these as soon as I get caught up.

I model era 3 or 4. About 1940s to 1960s steam.

Ok, I also model the GWR about 1934-39. Look for more on that this fall.

Which website? I shut down my old website several years and that url is available but I do have a free Wordpress site that I still use for posting occasional things and it is not available.

@@TheDCCGuy it is just that your pinned post refers to your non-existent website and I was interested in viewing the article you mention in it. Would you consider updating your pinned post to reference the mentioned article if it still exists?

That post is almost 6 years old and I don’t have time to go back and update all my videos from the last 6 years. I suggest you either find a copy of the article in MR or look at my follow up videos on this subject of which there are 2-3. You can also do a Google search for keep alive schematic and you will find a number of these.

Ok, I have loaded a copy of the scenatic to my Wordpress website at larrypuckett.wordpress.com

@@TheDCCGuy thank you. Sorry but I hadn't realised you did an update 3 years ago. The problem is RU-vid just randomly throws up stuff related to whatever the viewer last looked at and I didn't think to review your channel for updates. When I found you website was gone it made me wonder if you'd moved it some place else.

No problems in most steam loco tenders and in many HO diesels. However for smaller installations I recommend using TCS KA1 or KA2 Keep Alives. These are the smallest I know of and still give you enough power to get over dirty spots and dead frogs without losing sound or creating jerky operation.

Not that I know of.

If you had access to an oscilloscope and a function generator (set to a square wave) you could possibly look at the charge and discharge IV curve of it to see if it's working correctly I would think. Although that may be beyond most people's wheel house as far as equipment they own.

I am not familiar with those and haven’t looked into SMD components for this purpose. The technology is changing so fast I just don’t have time to keep up with it anymore, especially now I am doing this RU-vid channel! Even thiugh you are using 2 caps rated at 10V each they shouldn’t charge up to more than the input voltage which for most systems would be about 14V. I know that YouChoos in the UK is using various designs of stay alive boards with SMD tantalum caps and super caps but none of his are rated at more than 120mF and 16V. Here is a link to his website www.youchoos.co.uk/Index-Shop.php?L1=StayAlive . I encourage you to experiment and if you do, test your design on a cheap old mobile decoder instead of a new LokSound or other expensive one. I can send you an old one of mine gathering dust if you don’t have any laying around. Also there is another video on RU-vid showing how to build a similar stay alive to this one using SMD components but with standard SuperCaps so you might want to look it up for added inspiration. I don’t have a link but just search for keep alive. Let me know what you come up with-Larry PS-Also take a look at this YouChoos webpage on his caps and circuits for keep alives. Lots of good info there.

Larry, thanks for your answer!! I got some 3300uf 16V (16 x 16 mm) smd supercaps and installed one directly inside the locomotive with the diodes and the resistor. I think one capacitor provides more energy. I tried it with a NCE 14SR and Soundtraxx Tsunami. Obviously, the non sound decoder keeps on for more time.

I do not recommend it as they use a 3 wire keep alive.

@@TheDCCGuy ok , quindi solo per laisdcc? Grazie.

Chinquapinmayor Well yes you could but there are other issues which I discuss in the DCC Corner column. That will be in the next issue of Model Railroader so read it and see if it answers your questions. You really would need to use the proper Zener diode to protect the capacitors.

No, not enough voltage to run the decoder, it will cut out. 4 capacitors minimum. 5 gives a little more voltage margin, but most commercial KA's use only four. I have built them from 2F caps that were the same physical size as 1F's, 8 x 12 mm, but have since begin to use the smaller 1F caps that are the same used by TCS and others.

If you watch the other two videos on stay alives I explain how they work. The resistor prevents inrush current issues and the diode forces current to flow through the resistor when charging.

It acts as a voltage regulator and shunts power around the caps when the input voltage exceeds the total of the capacitors. If you are sure your input voltage will ALWAYS be less than the total of the caps then it is not necessary.

Model Railroading With The DCC Guy Ah, yes interesting circuit. I find it difficult to obtain “super-caps” but will check out your recommended sellers. Thanks.

Probalby best to step down. The Zener protects the caps from overcharging. They will try to charge up to the voltage of the track power. So if your track is 14 and your caps total 15 you won’t even need a Zener. But if they are 13 then they could overcharge. But, a 13V Zener would protect them.

@@TheDCCGuy They come after the rectifier on the board if using dcc that is regulated dc not track power in DCC THAT IS A FORM OF A/C that can be measured with a DVOM on A/C mode. The caps are like a battery that charge up in a reserve so when you lose power from the rail it is released to discharge.

I guess we have to buy the magazine, cool marketing trick.

Go to DCC Guy's website: www.dccguy.com/?s=stay+alive His May 23rd 2018 post shows the circuit, and his June 22nd post gives the Part Numbers. It would have been much easier to show both in the video though!

@@ROwen-Cymru i0.wp.com/www.dccguy.com/wp-content/uploads/2018/05/0E4B199A-402D-43C2-A21E-E300F25BA03B-e1526929605104.jpeg

@@ROwen-Cymru the website is no longer there, its been moved/ deleted?

They are 1 farad.

That can be straight forward or complicated. For more recent decoders check the instructions for info on where to make the connection. I talk about this a bit in my current October 2019 DCC Corner column. On older decoders you have to do a little detective work. There is comprehensive info on this website www.members.optusnet.com.au/mainnorth/alive.htm about where to make the connection on older decoders plus it gives tips for finding the spots on others.