Video of Stay alive demo

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How to overcome dirty track

I have just posted this on my Granby thread ……I thought it might be of interest to a wider audience……I do actually recognise that not everyone believes that modelling begins and ends with the GWR circa 1948.

Just ignore the pretty pictures and go to the semi-techy stuff halfway down :lol:
 



12 years ago, when I first started to learn about the mysteries of DCC,  the lower level branch line was the first section of track that I  laid.  I am afraid I didnt do a particularly good job. Its a bit uneven  in places and in those days if you wanted to isolate the electrofrog  points, rather than snip a little wire you, had to make the cuts  yourself with a Dremel. I have some horrible gaps….carefully filled  but of, course, without power.


The 57xx panniers that take the B Set to and from Granby manage to cope  very well with this uncertainty. The autotrain does not! I have  struggled for over three years with both a DJM 14xx or the 64xx  .

 



The 64xx is the better of the two but despite constant wheel cleaning  and finely adjusted pick ups it still requires far too many little  nudges from the sky.


When I get really frustrated I have even been known to substitute this  ancient Lima rail car, which I believe I bought in Beatties, Sheffield,  in 1998!




You may well ask why this 20 + year old model, notorious for its pizza cutter wheels, can out perform a modern Bachmann loco?

Well the wheels have been updated and additional pickups have been  fitted. However the principal difference is that a Stay Alive capacitor  is wired to the decoder.

A capacitor is a sort of battery that stores up power and supplies it to the decoder when the decoder detects a power outage.

I have three in use on Granby. They have some downsides……they are  bulky, expensive and used to come pre wired to a specific decoder. I  have found the best value for money to be the TCS Keep Alive range. The  problem is that I cant abide the TCS decoder with its erratic speed  curve.

I was about to hold my nose and fit one in the Autotrain and hard wire  it to the 64xx when I discovered that you can now buy the TCS capacitors  separately and they have been on a diet…..much slimmer:
 



The next problem was how to attach the KAT2 to the decoder…….the  64xx is designed to accept a 6 pin decoder that plugs directly into a  pre-wired socket…..ie no wires.

I have been meaning to try a Zimo decoder for some time. They have a  relatively inexpensive 6 pin decoder with two largish solder pads for  the blue (+ve) and black/white (-ve) wires.

I emailed John Gymer of Youchoos to ask his advice before ordering from  him. He was super helpful and made a number of very helpful  suggestions…….including an even smaller and far less expensive way  of storing power …..unfortunately the KAT2 was already  ordered……..but more on this later. 


Here is the rig to be fitted inside the 64xx




KAT2 Capacitor to be connected via a tiny protective device (Lifelink)  to the Zimo decoder….the two  "largish" solder pads are bottom left.

I had intended to put the capacitor either on the cab floor or in the  bunker but had forgotten that the decoder socket is right at the front  of the loco.




Fortunately I was able to fit both the Lifelink and KAT2 underneath the decoder



I have learned to take things like this very slowly and carefully but  even so I dont think this took more than an hour to complete.

And here is the result



[yt]0GSO-d0bzW8[/yt]




I dont expect to ever have to run the loco over 18" of un-powered track  but clearly there is now sufficient power in reserve to overcome any  gaps,dirt or insulfrogs.

Here we see 6407 complete with new fireman and a new headlamp moving smoothly over a turnout previously known as Stall point!





I now have a cunning plan to deal with the DJM 14xxs


Regards from Vancouver[yt]0GSO-d0bzW8[/yt]

John
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Hi John,

Not sure you need stay-alives with the Lima Diesel railcars. Properly wired with decent pickups all around and after-market wheels they can go over nearly 8" of dead track. 


One problem I have found with stay-alives and DCC is that they continue to run without any control. 


Nigel


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Wow! That is amazing! I think I need to look into that for a few of mine! They are so temperamental no matter how much I clean the track/locos :-(
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[user=1632]BCDR[/user] wrote:
Hi John,

Not sure you need stay-alives with the Lima Diesel railcars. Properly wired with decent pickups all around and after-market wheels they can go over nearly 8" of dead track. 


One problem I have found with stay-alives and DCC is that they continue to run without any control. 


Nigel

Hi Nigel

 You can control the output duration by adjusting a Cv value on the  Zimo decoder. I dont believe I will need to though.

Regards

John

John
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[user=2057]TeaselBay[/user] wrote:
Wow! That is amazing! I think I need to look into that for a few of mine! They are so temperamental no matter how much I clean the track/locos :-(
Thanks Chris

Hopefully you will be even more impressed if I am successful with the 14xx…..thats this weeks job

Regards

John

John
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That's quite something John.

They are indeed magical things and, IMHO, almost essential in the case of short coupled sound locos, although that won't worry you John …………..yet ……….!!. 

I would imagine the peace of mind for you automating with RR&Co must be worth it's weight in gold.

Once again - stunning pictures of Granby.  :thumbs :thumbs

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John great presentation showing  how well adding the unit makes a massive difference.

One question are you able to adjust the length of time the Stay Alive is active for or is that a fixed length of time.

I ask as running for 18 inches longer with no power in some cases may cause a hiccup.

Brian

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[user=2137]Briperran[/user] wrote:
John great presentation showing  how well adding the unit makes a massive difference.

One question are you able to adjust the length of time the Stay Alive is active for or is that a fixed length of time.

I ask as running for 18 inches longer with no power in some cases may cause a hiccup.

Brian

Thanks Brian…..glad you like it

With the Zimo decoder you can adjust a Cv (153? ) in increments of 0.1 seconds.

Petermac asked a similar question on my Granby thread……I dont see it as an issue on my layout I just want it to overcome the stutter you can get…scrap of dirt ,insulfrog etc that can mess up automatic operation.

Best wishes

John

John
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Thanks John

Thats great you are able to adjust it obviously its dependent on the individual decoder having an adjustable CV.

I certainly know there are certain locos i will be looking at implementing this on

Brian

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Me also Brian. Thanks for the demo John.
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Thanks guys.
Dont rush out and buy a capacitor just yet though! This morning I am going to try and fit some much smaller and cheaper to a DJM Hattons 14xx……I will let you know how it works out

Cheers

John

John
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That will be very interesting John
I do have a DCC concepts Zen nano decoder with a stay alive fitted to it but i have not tried it yet.

So how a cheaper one performs will be interesting.

Brian

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Any ZIMO beats a ZEN hands down, whatever the price.

Just to explain a little further, if the decoder detects the loss of a DCC signal (therefore DCC power) it draws current from the Stay Alive capacitor. As soon as the decoder sees a DCC signal it stops using power from the capacitor and indeed begins to recharge it to full capacity.

In this sense, the maximum duration of Stay Alive power is almost irrelevant as long as the capacitance can cope with the power requirement in the gap between seeing DCC signal.

However, as a safety measure, the maximum duration of each single power distruption for which the ZIMO decoder will draw power can indeed be limited by CV153.

But the ZIMO is far cleverer than just that simple trick.

If the decoder receives a 'stop' request from the controller it will do so either by coasting to a halt following CV4 values or more quickly if the Manual Brake Function has been activated.

In either case, if the decoder continously monitors the condition of the DCC signal. In the final milliseconds before the motor stops completely, if the decoder has detected a poor DCC signal, say dirty track, it will continue to turn the motor (at barely perceptable speed) using power from the Stay Alive Capacitor until it detects a reliably good DCC signal. This is entirely automatic if a Stay Alive has been fitted and will prevent the model stopping in a place where there is no power available for a re-start.

The only proviso is that there is sufficient capacitance in the Stay Alive to power this during the transition of the dead spot. This is why a large capacitance Stay Alive is very useful, even if you don't want your models going 'off road'.

https://youtu.be/l7W_Q6b-lwc

The Stay Alive (my own DIY pack of 6 x 1Farad 2.7v supercapacitors wired in series, costs around £6) performs from about 2min 50 seconds in.

Worth noting that the ZIMO is the only one which has the ability to control Stay Alives when operating on DC (analogue). It's smart enough to know the difference between a DC voltage reduced to zero deliberately and a track power outage.

I've fitted ZIMO decoders with Stay Alives for people who have no intention of running DCC. ZIMO decoders fitted solely for Stay Alive control on analogue.

Some of the ZIMO decoder range do not need the Lifelink (or ZIMO's own SAC11) as they have all the necessary circuitry on board as standard.


Best regards,

Paul

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Hi Paul,

Most helpful post regarding SA Ops. The section with the Supercapacitors is very interesting. A friend built a similar set for me to go with a Zen Nano and it worked for a while but then died. He did some research and found that the low price Supercapacitors, presumably similar to yours, are rated to deliver in the 100-300 microamp range for very low current uses and that discharging at the 30mA or so needed for even a small OO loco would short them out in no time.  This made sense to me at the time, otherwise why would the likes of LSU, Zimo, DCCC etc sell very expensive capacitors if a cheaper version would do just as well?

Clearly you've shown otherwise. Is there a trick which he missed?
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Great video Paul and brilliant "after power" running !!!

My current (new) layout has quite a number of dead frog points and it occurred to me that it may be a cheaper option to fit these stay-alives than to change them all to live frogs ……………….. :roll: :roll:

Firstly, how big are they physically - I recall space was a bit tight on the Hornby J50 you chipped for me although it's a brilliant addition to the Class 08 you did.  Are they fairly easy to fit - as you know, I'm not good with electronics and small spaces…………………………….. :oops: :oops: :oops: :oops:

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It's not the frogs that are the problem. The dead section is very short. The issue is the power routing design, point blade to rail contact and the hinged joint.  One minute with the multimeter will identify whether you have iffy conductivity and dead spots. Dirty wheels and wipers are usually the issue. Two out of three poor contacts on one side of an x-6-x will make it stutter as it goes through at speed, or stop at slow speed as the only conductive wheel comes onto the frog. Again, some testing with the multimeter will show whether any wheels need a good clean or wiper adjustment. 

Add to the above over-enthusiastic use of abrasive cleaners on the pressed point blade and an uncompensated chassis.

Throwing a capacitor into the mix rather than addressing the underlying problem(s) seems counter intuitive. Some locomotives have poor wiper designs or come out of the box with only a couple making contact with the wheel. 

Moral of this is that with everything working you do not need big capacitors, a small one to overcome micro-pauses in continuity is fine. Logical conclusion of course is to never clean track, get rid of the wipers, and fit LiPo batteries. And use radio control.

Nigel



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In the perfect world of perfect track laying, perfect wiring, perfect maintenance and perfect cleanliness Stay Alives would be virtually redundant.

No one suggests that Stay Alives absolve the operator from trying to achieve the perfect set up. Unfortunately, for a variety of reasons, not everyone can achieve this at all times.

If you fit a Stay Alive and there are no breaks in track power, nothing is lost. But if you fit a Stay Alive and you model encounters a power outage, it will be able to continue until it finds power. 'Win Win'.

Sorry if this seems counter intuitive, seems eminently reasonable to me. Belt and Bracers? ('suspenders' doesn't seem to work as well in this context).

What if you take your loco to someone else's layout over which you have no quality control? If the layout is below par in supplying reliable power, your model may run like a dog without a Stay Alive, but go like a train with a SA.

Switching to battery power and Radio Control may be a viable option for some, but comes with issues of it's own.

As always, horses for courses.

Best regards,

Paul
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Both the previous posts both are correct in what is being said.

If you have for example an 8ft plank with a minimal amount of track on it yes you can be fastidious in ensuring that all trackwork is exact so therefore no need for stay alives.

If you have a larger layout with a great deal of trackwork over a large area and perhaps at different levels you cant spend as much time laying if you want to finish before you die and over a period of time errors will probably occur, therefore considering Stay alives is a sensible option.

Paul you mention certain capacitors in your post is there a link for a supplier of those please. and i assume you need other bits like diodes and resistors?

Brian

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Yes, sorry Nigel but on this occasion, I agree with Paul…………………

Of course we'd all love to have perfect locos running on perfect layouts.  I'd also like those perfect 4 numbers in the Lotto - unfortunately, both evade me ……………….

I suspect that, if perfection was a pre-requisite of railway modelling, there wouldn't be any - railway modelling that is, not perfection.

I wasn't aware that, other than the plastic insulation at the frog, that the electrical contacts differ between live and dead frog points but I'm prepared to learn ………..  I solder a wire between the switch and running rails on all my electro points - can I also do this on dead frogs or would it create a short ?



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Hi Paul,

Interesting points (specially as this is your business). But let's have a look at this from another perspective.

So…Your layout is equipped with stay alives, even although you know you have a couple of dodgy sections of track that for any number of reasons have continuity issues (hard to get at it for example). And then your friend pops over with a brand new DCC equipped locomotive that sadly doesn't have a stay alive. Oh, the embarrassment, you have to fess up that on spite of being the ace modeler in the club you have defective track at home. And you are really not looking forward to the next club meeting.

I am an occasional member in a large modular layout. When at a show people turn up with a locomotive they would like to run. So the layout (often up to 50 x40 feet) can't have dead spots that only stay alive equipment can get over. In this case your home layout track is a club module, so it had better be fault-free. Or you get banned until it is.

I am not advocating against stay alives. Where there is space my locomotives get decoders and stay alives as I only run DCC sound and there constant power is a must.  What I am advocating is that track is functional and has electrical continuity. Whether frogs are dead or alive is immaterial as long as they are less than the wheelbase in length. A dead frog is not a rational for equipping everything with stay alives. Space is tight in a lot of small locomotives - decoder, speaker, stay alive capacitor. There is no reason why a capacitor cannot have the wiring extended and placed somewhere remote from the decoder If you want that. But do it for the right reasons.

Tantalum capacitors are known for having tantrums and exploding. Especially cheap ones wired in series to up the voltage. They recommendations are that they are only used at 50-60% of their stated voltage. They are nowhere near robust as electrolytic capacitors. Hopefully Zimo decoders know this. I suspect you would need voltage splitting ability (as in LiPo batteries).

Track is an intrinsic part of the hobby. Treat it as such. If done properly any gaps in tangent track are less than 1mm, bit more over  modern frogs. Long, dead frogs in  older points could be a problem with a short wheelbase 0-4-0, in which the cure is an electrofrog, not a stay alive. What if you friend turns up with an 0-4-0?

I'll stick with my comment, installing stay alives to address problematic track is counter intuitive. What should be done is to address the track problem, not use the stay alive as the solution.

Nigel








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