Loksound 5 Stay-Alive with 2200uF Capacitor

[KrisTeel]

Has anyone had anysuccess hooking up a 2200uF capacitor (as opposed to the ESU Powerpak) as the stay-alive solution shown in the Loksound 5 manual?

In section 6.12 Connecting Capacitors, they describe two keep alive solutions. I tried adding the simple 2200uF Capacitor solution (Figure 39) and despite following all of the instructions it doesn't seem to provide any power if no power is picked up off the rails.

I tried changing the CVs but suspect they only apply to the ESU Powerpack option. I've tried two sets of cap/diode/resistor lash ups with brand new components, exactly as shown in the manual and even after 10 minutes there's no stay-alive.

Its the standard Locksound 5 decorder as supplied by Rapido (they've confirmed that OEM and retail decoders are identical.

Any suggestions and ideas would be appreciated.

Thanks and cheers,

Chris T

[peahrens]

I'm looking at the April 2021 Lok5 manual and it shows this on Fig 41, pg. 49.  I don't yet have any Lok5s but lots of Loksound Selects, and those show the same configuration: 2200 uF capacitor in series with parallel resistor and diode. 

I used this setup in an Athearn Genesis GP9.  I had replaced the Tsunami with the Select but found some occasional sound hiccups due to just slightly dirty track, wheels or rail contact (at a triple crossing).  So I decided to try the capacitor setup.  I used simple Radio Shack capacitors (not the smaller supercapacitors in typical commercial keep alives).   The 2200 uF would not fit in the short hood space available so I tried a 1000.  I recall it helped to reduce sound hiccups, where very short interruptions can be heard.

I just tried a simple experiment by turning on the headlight and tilting the loco to interrupt power.  The light takes a few seconds to get dimmer and shut off.  With another GP loco not having the capacitor, the light goes off immediately.  So, the conventional capacitor can work, a bit.  The 1000 uF gives it some help but it does not go running down a dead track much at all.  If I were doing today, I would use a TCS Keep Alive or Soundtraxx Current Keeper (of an optimal size for the space) that would provide much more capacitance in a small space.   

You might try the headlight experiment as a way of seeing whether the capacitor is doing anything.  Check the diode direction is correct.

Curiosity...what type capacitor are you using?  What type / scale loco and where does it fit?  The (unused) 2200 uF typical capacitor I have measures about 32mm L x 17mm D, pretty large.

BTW, I recall that installing a simple capacitor (not the ESU Powerpack) creates an issue about using the LokProgrammer; e.g., for sound file replacement, unless the simple capacitor is disconnected (a small on/off switch would be ideal).  I see that note is still in the manuals.  

[tstage]

peahrens

Curiosity...what type capacitor are you using? What type / scale loco and where does it fit? The (unused) 2200 uF typical capacitor I have measures about 32mm L x 17mm D, pretty large.

Yea, I installed a 2200uF cap as part of a keep-alive circuit in a Bowser VO-660 switcher and it just fit in the cab area.  It was hooked up to a Loksound Select and worked "okay".  Like Paul, I found that it helped with the sound hiccups on less than ideal track but I don't remember the headlight staying on any longer when the power was shut off.

Tom

[peahrens]

For those interested, the (latest) TCS KA2 has a form factor of about 9 x 9 x 16mm.  The prior version (older chart attached) had, for $27 (current street price) about 90 times the capacitance of the larger conventional 2200 uF capacitor.

As I noted, I found the conventional capacitor an interesting newbie experiment but would not repeat it.  I have installed keep alive type capacitors (TCS or Soundtraxx) in perhaps 10% of my locos , as warranted.  I think my track cleanliness is better than average.

KA/Stay-Alive Devices - Mark Gurries (google.com)

Keep-Alive® | Train Control Systems (tcsdcc.com)

 

[KrisTeel]

Hi Paul,

Thanks for your reply. First some info:

2200uF 25v cap
25mm x 10mm D
Fits perfectly at the back of a Rapido FP7 if you slide the speaker forward just a bit.

As I'm accustomed to the TCS Wow kits with keep alives I expected to get a few seconds of power, but it just might be that it provides just a few milliseconds of power to keep the sound going.

I went back to do the headlight test and so long as the motor's not drawing power, I can see the lights dim off a little bit slower than with the cap.

And yes, you do have to disconnect the cap when programming. I use JMRI talking to a PR4.

Thanks for your help and Mark Gurries link!

Chris T

[5150WS6]

I also have switched to using the TCS capacitors and am happier with the price compared to the Loksound powerpacks. 

And I've had good luck programming with the capacitor still wired. But after each save or write to the board I remove the loco from the track for about 1 minute making sure all power is drained and there's nothing left. That has pretty much taken care of having to desolder the pack each time. I'm using the Loksound programmer. 

 

Mike