speedybee hon30critter Could you post a diagram with the resistors Imgur won't seem to let me upload a picture from my phone without downloading the app... I can do it from a computer tomorrow. Realistically though, I'm probably making a mountain out of a mole hill here. The circuit as drawn likely usually works fine for typical model railroading, since locomotives are only used for a short session once in a while... Not all day every day. Anyways, if it does fail, it's probably not going to be catastrophic. Supercapacitors don't catch fire like li-ion cells. But rather than resistors, a better easy solution is to connect a 2.5v zener replacement IC, such as TL431, across each capacitor, so that each individual capacitor can never exceed 2.5v. And then you could ditch the 13v zener; you wouldn't need to limit the voltage of all the caps, since each cap is individually limited
hon30critter Could you post a diagram with the resistors
Could you post a diagram with the resistors
Imgur won't seem to let me upload a picture from my phone without downloading the app... I can do it from a computer tomorrow.
Realistically though, I'm probably making a mountain out of a mole hill here. The circuit as drawn likely usually works fine for typical model railroading, since locomotives are only used for a short session once in a while... Not all day every day. Anyways, if it does fail, it's probably not going to be catastrophic. Supercapacitors don't catch fire like li-ion cells.
But rather than resistors, a better easy solution is to connect a 2.5v zener replacement IC, such as TL431, across each capacitor, so that each individual capacitor can never exceed 2.5v. And then you could ditch the 13v zener; you wouldn't need to limit the voltage of all the caps, since each cap is individually limited
As per the diagram that was posted, that's exactly how the commercially available versions are constructed. Adding more components also increases the physical size of the package which is always a concern when space is at a premium.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Hello All,
Thank you for your reply on the type of decoder currently installed (excuse the pun).
Soundtraxx offers two (2) Current Keeper™ Energy Storage Devices (ESDs) that are compatible with their decoders.
The Current Keeper™ seems to be a plug-and-play unit, while the smaller Current Keeper™ II seems to be a hardwired option.
Seeing how space is a limiting factor a DYI unit might be too big for your application.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
Puckett has a video on DIY keep alives
Henry
COB Potomac & Northern
Shenandoah Valley
speedybeeA basic method of balancing series capacitors is equal high-ish value resistors, say 10k, across each capacitor. A bit crude but better than nothing.
Hi speedybee,
Could you post a diagram with the resistors that you suggested should be added to the circuit? I think I understand what you are suggesting, but I am absolutely not confident in my electronic skills enough that I could get it right.
Also, there has been mentioned in the past that a keep alive circuit can interfere with reprogramming a decoder. Can you address that potential issue?
Thanks,
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
hornblower
Hopefully Larry Pucket knows more about electronics than I do (entirely possible), because to me, this circuit looks incomplete. It should have a way of balancing the series capacitors so that over time they don't get out of whack and some of them start going over voltage.
Maybe if your five capacitors all rolled off the same assembly line at the same time they'd be well enough matched that you'd get away with this, for a while at least. But personally, I wouldn't risk capacitor meltdown.
A basic method of balancing series capacitors is equal high-ish value resistors, say 10k, across each capacitor. A bit crude but better than nothing.
In answer to a question, the RS3 has a Tsunami decoder so a separate current keeper will be necessary. The RS1 which runs without the problem has a TCS decorder with built in current keeper. A couple more road switchers are in the pipeline and I plan on using TCS equipment in them.
MH
I've always had (good) intentions of making my own, but never got around to it. A quick look on ebay shows a lot of 50 1F / 2.7 volts capacitors can be had for only $13.36 with free shipping ! I'm sure the other components are but pennies apiece as well. A little effort building your own can sure save a lot of money.
I would suggest building your own keep-alive circuits. Check out Larry Pucket's YouTube channel for his episode on DIY keep-alive circuits. I have built and installed a number of these circuits in my own locos and, WOW, what a difference. The big surprise was how much slower the locos can be run as they always have a source of power to draw from. I can run trains at around 10 smph, shut off the entire layout, and the trains will continue to run for about two feet! The LED headlights will stay on for between 20 and 30 minutes.
The parts list for the circuits I built are as follows:
Nichicon Supercapacitors 2.7 volts 1 Farad
Mouser Part #: 647-JUWT1105MCD
TE Conectivity Carbon Film Resistors - Through Hole 100 Ohm 1/2W
Mouser Part #: 279-CFR50J100R
Taiwan Semiconductor Rectifiers - 1A 1000V Rectifier
Mouser Part #: 821-1N4007G-KROG
Onsemi - Zener Diodes 13V 5W
Mouser Part #: 863-1N5350BRLG
I purchased enough parts to make 5 keep-alive circuits for under $30. As I purchased 10 of the resitors and diodes, I need to buy 25 more capacitors ($10.43) to make five more circuits. See the schematic below.
Hornblower
The RS1 and RS3 are almost identical body shapes. What keep alive did you use in your RS1 ? Fitting it into the RS3 would be pretty much the same.
Calapooya Seems to be track conditions at the club where it runs. I have another Bachmann RS3 with the same but lesser problem and an Atlas RS1 with current keeper which does not.
Seems to be track conditions at the club where it runs. I have another Bachmann RS3 with the same but lesser problem and an Atlas RS1 with current keeper which does not.
I have the same problem. The track at our club quickly gets very dirty. Lately, some members have been putting all sorts of oily junk on the rails that only made it worse.
These have been my solutions to the dirty track situation:
1) When I arrive at the club, I clean the track I intend to use.
2) We realized that part of the problem was high humidity during the summer. The quality of the track improved when we installed a dehumidifier.
3) Six axle diesels and steamers with all-wheel pickup in the tenders are less prone to stops due to dirty track.
4) I considered changing my decoders, but I cannot afford it (I have many locos). So I learned how to harmonize the speed of my locos and I mostly double-head them at the club. This has been very effective.
In your case, if your loco has the "factory installed" sound, I would not touch it. Unless you don't care for the sound, replacing the decoder with a keep-alive and sound might be difficult. That loco does not have a lot of spare room inside. Besides, you seem to say that other locos have the same problems. But I would be curious to know from others how they addressed the poor power-pickup issues on their RS-3s without changing the decoder.
Simon
CalapooyaSeems to be track conditions at the club where it runs. I have another Bachmann RS3 with the same but lesser problem and an Atlas RS1 with current keeper which does not.
I have one of those Athearn RS3s. While the shell is very nice, they did not come with very good pickup. Athearn also glued the incandescent bulbs to the headlight lenses so that replacing them with LEDs is a real pain.
I would try to improve the pickup issue before installing a keep-alive...
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
CalapooyaI have an Athearn RS3, DCC ready with sound installed.
The term "DCC Ready" means there is no DCC decoder installed.
Sound functions can be triggered by an analog DC system but does require a DCC decoder installed.
Many Energy Storage Devices (ESUs) A.K.A. "Keep Alive®" are proprietary to the decoder manufacturer.
Letting the great folks on these forums know the brand and type of decoder installed will help them answer your query.
May I ask why it needs a current keeper? Sounds odd to me for a loco that long a wheelbase to need something like that.
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
I have an Athearn RS3, DCC ready with sound installed. It desparately needs a currnet keeper. Space is limited. Suggestions for what unit to buy and where to put it.
Mark