How to use Capacitors to add EXTRA Power to a Tight Decoder Install

Some installs are too tight to fit a CurrentKeeper to maintain power over dirty track and switches. In these cases you can often fit a capacitor or two for a little power boost. In this video, George walks you through some simple tips to adding capacitors to your tight fit installs. He also shows you how to easily determine the polarity on our capacitors. Watch now to learn more!
Tsunami 220µF Replacement Capacitor: soundtraxx.com/accessories/in...
SoundTraxx CurrentKeeper: soundtraxx.com/accessories/in...
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[@larryriehle166]

Very timely. I recently painted the rail webs on a section of my layout and missed a tiny area where I didn't get the paint off of the top of the rail. My locomotives with the current keepers in them rolled over the spot without a problem but my 060 saddle tank with a capacitor in it didn't. Now I want to add as many capacitors as possible to this little guy. Thanks for doing what you're doing. I hope whoever you replace Josh with will be of the same caliber, he was very helpful to me with my first venture in adding tsunami 2's to my locomotives (so were you, love you guys). Keep up the good work.

[@SoundtraxxDCC]

This should definitely help you out! Yes great timing. We are working hard to find a suitable replacement for Josh, but he has big shoes to fill! Thank you for your feedback!

[@BNGreen970]

George, Not sure if you still look at comments on videos this far back. But I wanted to thank you for this one. I just did this very install on of the new Athearn SW1500s. Kudos also to Norman for his quick reply to my email and his help in where to connect the two capacitors to the Athearn 21 pin board. Merry Christmas to everyone at Soundtraxx.

[@SoundtraxxDCC]

Thank you for the feedback! We are glad this was helpful. Happy Holidays to you as well!

[@artyz2002]

Thanks George. Just what I need, and looks like many others too. With many of the Australian models, space is very restricted. Now this has given the advantage to make my own.

[@SoundtraxxDCC]

I'm glad this is helping you!

[@DamonGaskin]

OMG! Right on time George! I was just thinking about contacting you all on this! Awesome! Awesome! Awesome!

[@SoundtraxxDCC]

Perfect! Let us know if you have any other questions about this.

[@tct855]

GG 👀, Nice to see that home ec class is paying off. 😊 You speak the truth on caps! Having said that, this particular demo is exactly why "Good" all wheel pickup is still important. When I build a model (any engine or powered rolling stock) I always make sure FIRST that I have good clean reliable much needed power pickups, then as a back up - good cap-paks always help against those pesky dirty rails/switch points or insulated frogs. Even in modeling, a good foundation is key when building up the ultimate model. Love the pictorials my friend! Thanx Thom...

[@SoundtraxxDCC]

Thanks for the feedback!

[@1621billw]

This is a really good idea that never occurred to me. Thanks for sharing it as I'm finding that space is at a premium when working in n scale.

[@SoundtraxxDCC]

Glad it was helpful!

[@Bill-kx5yh]

Once before, having been in a hurry, I accidentally reversed the polarity of a custom capacitor install like this. It was like a small fire cracker inside the model. The end of the capacitor blew off. Be careful with polarity like George says. Model Railroading is fun. 💥

[@SoundtraxxDCC]

Yes, polarity is important here. I bet that was exciting!

[@hughfordmusic6736]

It appears that every one who watched your video understood where to solder the wire from the capacitor to the locomotive. I didn’t, where is the connection between the capacitor and the locomotive Thanks

[@SoundtraxxDCC]

It will vary based on the decoder format used. On most of our current decoders, there is a 2-pin plug that simply plugs in. You can get the 810158 harness from your local store or from our website. On some occasions, primarily older decoders, and the 21P, you will need to solder the wires to a specific location on the board. This will depend on which board you have. So, for guidance on this contact our support department for assistance at [e-mail] or [phone].

[@frankhellman6879]

Side bar? ⚡🔥♨ NOW you tell me! 😆

[@SoundtraxxDCC]

We overlooked this tidbit at first!

[@schmidtw900]

I'm about to start adding my own custom builds like this on my locos and am wondering what the 2 pin CK connection fittings are called so that I can make my own harnesses to connect to the two pins on your decoders and maybe repair some other 4 to 5 pin ones on some Atlas engines.. Thanks !!

[@SoundtraxxDCC]

John, you can buy the 2-pin harness off the website and use them for attaching a CurrentKeeper (or other stay alive module of your choice) tot he Tsunami2 and Econami product line.. You can see it here: soundtraxx.com/accessories/installation-accessories/wiring-aids/currentkeeper-2-pin-harness/ I hope this helps.. Contact us at [e-mail] if you need further assistance. Thank you! ~G

[@spacecalander]

George, if they are side by side, don't you solder negative to positive down the row so you have positive at one end and negative at the other? You showed negative to negative when using only two caps correct? or match polarity when using only two caps?

[@SoundtraxxDCC]

In this case, capacitors are added in parallel. So if you add more, wire in parallel to ‘extend’ the 2 plates storing the energy between. If you are in series, then you’ll be limited by the smallest cap. I hope this helps.

[@MikesProjectsandHobbiesMC]

So we don’t need a diode or resistor between the decoder and the caps? You can make an cap bank in parallel and connect it right to the tsunami keep a live port?

[@SoundtraxxDCC]

The diode was there to slow the charging rate, but with only 1-2 small 220 uF caps, the charge is not enough to cause problems. The issue is the high-capacity stay-alive modules like the CurentKeeper draw lots of current to charge to full capacity, so some DCC systems can see the inrush of current as a direct short, and trip the breaker. So the diode and resistor slow the charge rate so the DCC system is none the wiser. Thank you!

[@adamserafini6945]

Can 1 current keeper be used for a steam engine with a sound only decoder and a separate dcc decoder for motor control ?

[@SoundtraxxDCC]

2) I would recommend that each decoder has it’s own CK if possible. I cannot say that it would so why take a chance? The motor decoder needs a little less for the processor, so you could use a smaller bank of capacitors for the non-sound and a CurrentKeeper for the sound. BUT.. If you use a Tsunami2, these are one in the same, motor control and sound in one unit, so you do not have to worry about it. Plus, the sounds are played based on how the model is being used, so you’ll get a more realistic operation using a single decoder and a single CurrentKeeper. Save space too!

[@geraldjones2278]

I just saw this on FaceBook and I think it would be helpful to go into more detail on exactly how and where you would wire this into the decoder. I know your 2200 series decoders have plugs to receive current extenders, keep-alives, or whatever you call them but exactly where you would solder any you make yourself and what lead goes where is not clear.

[@SoundtraxxDCC]

Thanks for the feedback. You would wire in the capacitor just like you would a CurrentKeeper based on the wires positive/negative terminals. We even sell extra CurrentKeeper harnesses so you could wire the capacitor to that and plug it in just like a CurrentKeeper. For more assistance with this you can contact our Support Team directly: [phone] or [e-mail]

[@klaticus]

Can use a 25v capacitor with more microfarads? 330 or even 1200uf??

[@SoundtraxxDCC]

Yes, just be cautious that without any charging regulation, having many of these on the layout at one time nay trip the DCC system short-circuit protection. Otherwise, it will not harm the decoder. It’s just a power storage device. But having a 1200 uF ca on one loco should not cause this issue.

[@csxrensville5105]

I use your Tsunami 2 pnp decoders. They have a connection for a currentkeeper. I know you can purchase just the leads for the currentkeeper. If I use a small Capacitor can it be plugged in to the decoder using the plug on the board, and which colour on the lead is positive? Thanks

[@SoundtraxxDCC]

Yes, if you get the harness (810158) and plug in, the blue wire is positive and black is negative. Wire yo the cap or caps as you need. Thank you! CurrentKeeper Harness: soundtraxx.com/accessories/installation-accessories/wiring-aids/currentkeeper-2-pin-harness/

[@csxrensville5105]

@@SoundtraxxDCC Thanks for the info, much appreciated.

[@SoundtraxxDCC]

@@csxrensville5105 Of course! Let us know if you have any other questions.

[@louisfourie8404]

Hi could i use a 16v 2200 uf capisitor instead ?

[@SoundtraxxDCC]

Yes, but you could run into issues with the inrush current.

[@cdills3454]

I have a capacitor attached to a TSU 1100 boards green yellow stipe and blue wires but the loco doesn't seem to have any improvements in comparison to no capacitor at all, any advice?

[@SoundtraxxDCC]

The small 220uF cap only gives about ½ second longer, may not be immediately noticeable by the user. But when the loco is running, it does help. If you want longer, you can add more caps, or use a bigger cap. You can go up to a 1000 uF cap without any issues. Just make sure the cap is rated above his DCC track voltage. If you need to go higher, then you may be better off using a CurentKeeper.

[@cdills3454]

@@SoundtraxxDCC Ill give that a try, thanks

[@phillipg1588]

Don't Stay Alive caps also require a diode and resistor?

[@SoundtraxxDCC]

No, as it is piggybacking off the decoder’s own power circuit, the power has already been made suitable by the decoder

[@mafarnz]

Polarity is important! Things go pop if not.

[@MikesProjectsandHobbiesMC]

And the smell is awful.

[@SoundtraxxDCC]

Yes very true on both accounts!

[@Hofsan]

I have a real stupid question. Instead of using several 220uF capacitors, why not use a larger capacity like say a 330uF. Should be about the same size and longer run time. Just thinkin....

[@SoundtraxxDCC]

Capacitance is a factor of size. So the 330 uF 25v rated are a tad bigger, and probably could fit, but I used 220 since they were immediately accessible.

[@user-lp6ny2ry4z]

You do not want to use 100% of a component's rating - for example, I would never tell anyone to use a 16V cap in a 16V system, as this will lead to premature failures. 25V should be the minimum rating used in a DCC system. For reliability, components are derated to use only 60-70% of their spec ratings (leaving 30-40% margin), to lessen component stress and ensure long life. Furthermore, common aluminum electrolytic caps such as these age and degrade faster than most other types (e.g., ceramic), which only compounds the issue if you haven't properly derated them to begin with.

[@SoundtraxxDCC]

NO argument. You never really want to use anything at the max. good advice, and this is why we supply 25v caps.