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Keep Alive/ Stay Alive decoders

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Hi all

 

I notice that TCS have joined the growing band of decoder manufacturers offering keep alive/stay alive.

 

What is in the module, is it a capacitor or some rechargeable batteries?

 

The cost is about the same again as for the stand alone decoder so why is it so expensive?

 

Keith

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I noticed the prices too, but on further reading it looks like these modules are something similar to the Lenz USP modules (Power 1 & 3), rather than just plain caps.

That must account for the seemingly high price?

 

There are two Stay Alive modules available, both of which are available with or without a fitted plug for easy connection to matching TCS decoders. See here.

 

The KA1 (wires) and KA1-C (same but with a plug fitted) gives approx. 3 - 6 seconds power.

The KA2 (wires) and KA2-C (same but with a plug fitted) gives approx. 13 - 40 seconds power.

 

 

 

TCS have also introduced a whole range of new versions of existing decoder models, fitted with either wires or wires with plugs, designed to match these stay alive modules.

It looks like they've adopted this "big time"!

 

For example, the DP2X & DP2X-UK are both available with the option of wires (KA) or wires with a fitted plug (KAC), in addition to the original model.

DP2X-UK = (no fitment for stay alive)

DP2X-UK-KA = (wires for stay alive)

DP2X-UK-KAC = (wires with plug for stay alive)

 

The same for the 21-pin EU621, which is now available as...

EU621 = (no fitment for stay alive)

EU621-KA = (wires for stay alive)

EU621-KAC = (wires with plug for stay alive)

 

There are further examples right across their range of decoders (M, MC, T series etc.).

 

 

.

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I noticed the prices too, but on further reading it looks like these modules are something similar to the Lenz USP modules (Power 1 & 3), rather than just plain caps.

That must account for the seemingly high price?

 

 

.

Rather oddly when I looked at the TCS website they didn't show them although at the time DCC supplies had them in stock!

 

Keith

Edited by melmerby

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Rather oddly when I looked at the TCS website they didn't show them.......

 

They haven't yet updated all their website Keith. There's nothing showing under products, however everything is showing in the store part of the site - named "Order Page" in the menu on the left of the home page.

 

TCS - Home Page

Order Page

 

I picked up the news about this from the MRH magazine forum a couple of weeks ago, but haven't seen any other mention of it.

 

MRH Mag thread

Model Railroader

 

Ron

 

.

Edited by Ron Ron Ron

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A very interesting idea. Maybe the easiest solution to a problem I am having.

 

One of my Kernow/Dapol Beattie Well Tanks has started to balk a bit on Peco long insulfrog curved switches. I think one of the axel contacts is no longer working properly but it is in a semi sealed frame that I am loath to take apart. Yes, I have taken all the usual precautions of track cleaning, turnout tuning and loco wheel cleaning without curing the balk. My other BWT does not suffer a stuttering motion on the same turnouts.

 

I have already removed the six prong decoder plug and hardwired a TCS M1 decoder (but unfortunately bought prior to November 2011 with the KA plug) with more functions than the six pin. I could upgrade the decoder to one of the new TCS M1's and possibly get around the balkiness that way.

 

Very interesting. Off to the Hobby Store today. Will see about the availabiltiy of newer M1 decoders and the KA1C (no soldering if I don't have to.)

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If its just an occasional stutter, have you got room to add a simple capacitor to your existing decoder ? I found this makes a huge difference without the expense of a full stay alive module.

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I am running DC but this thread has got me thinking about a requirement i have knowing that a decoder fitted loco will run on DC. Specifically I have a need for a loco to run on for about 3 secs after it has lost the power feed due to the points closing. So does the "stay alive" feature work when the loco is running on DC power?

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I get fed up with posters looking for a magic fix to running problems .. My advice is get your track into good order and fit as many pickups as you can, or is this a case again of some not able to do and think there is an easy out of the box solution. Fitting multiple pickups will ALWAYS be the best answer. If you stop your loco on a bad section where connection is lost, how long will 'stay alive' survive, certainly not indefinitely. Don't know myself as never bought one and don't need one. I have locos on my VSU which holds 24 complete consists/locos, some that have been parked for weeks, and get virtually zero problems when I decide to operate, thanks to multiple pickups. I would concede that 0-6-0 s can present problems more than tender locos, again proving that its wheels in contact that succeed. Beeman.

Edit Just after I posted this comment I browsed MRF to find a poster had fried his decoder after 'fitting' a stay alive, Know which I prefer, Soldering dexterity required,not that I have not fried a number myself due to bad fitting..

Edited by beeman

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Of course more and better pick-ups are the ultimate solution - but not everyone has the skills to be adding them without making things worse. And what about the smaller scales, where a whole locomotive can weigh slightly less than one-ninth of not a lot? Wheel-rail contact itself is at a premium there. It should also be remembered that not everyone's layout is in a nice cosy environment, so condensation, dust, moisture etc are a daily hazard which needs offsetting.

 

I'm not sure that misfortunes with soldering keep-alives or decoders reflect anything other than just that - misfortune.

 

Affordable keep-alives do add value for some of us - and their burgeoning in the market-place reflects that.

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I have 5 stay alives and 4 of these are in 4 wheel locos. The only way to add more pickups is to run the loco with a 'shunters wagon' permanently coupled.

 

One of these has been run on DC and it does seem to have it stall on fewer times than other locos.

 

It is all for you to buy one and try it yourself.

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Have problems with one loco (a 0-6-0T) which has a distinct dislike to the station crossover (blundered there using dead frogs) so its likely to have a stayalive fitted, but intrigued by the DIY comments that arise. Does anyone have a circuit / where to connect it to on a decoder.

Edited by Butler Henderson

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I lik

This chap pioneered keep-alive capacitors on certain sound chips, and you may learn more on his page.

 

http://members.optus...north/alive.htm

I like the way he says it will run onto 12" of tape and whilst all wheels are on the tape can reverse direction!

 

Keith

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A cap, diode and resistor then and TCS admit to having a extra blue wire on their KA decoders so the black/white TCS wire is the green one on the web page examples at the bottom. As the decoder in the 0-6-0T is a M1 and nothing much bigger will fit it looks like getting a M1-KA and adding the bits to it (they should fit in the cab) as I don't fancy trying to solder to the M1!

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The TCS website now has a little more information, although the product category lists have not been updated yet.

 

They've also announced a version of the T series, called KAT series, with the Keep Alive built onto the decoder.

KAT1- series has the KA1 built-in and KAT2- series has the KA2 built-in.

Both are available in 2, 4 & 6 function versions, i.e. 6 different models.

 

KAT Series

 

 

There's a brief video on the TCS website too.

The YouTube version is here....

 

There's no reverse running shown, so my first guess was wrong and it doesn't look like there's any clever Lenz's USP type stuff included.

 

 

.

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Having read AMJ's post 4 wheel locos are definitely the most difficult, whether one is DC or DCC. The old Hornby 0-6-0's were in fact 4 wheel with their smaller dia. center drivers having no track contact. Having recently 'converted ' part of my DCC layout to switch between DCC and DC to operate an automatic shunting section, this problem arose trying a J39 and Jinty. Overcome by using the old method of 'compensation' as it was called, just on the rear axle. I drilled/tapped the chassis to fit a screw bearing on the axle center so allowing it to see-saw a little in an attempt to employ the 3 point landing approach. also filing the axle holes slightly to oval vertically. This was a marked improvement. The Hornby J94 having the current chassis with the sprung center axle was fine. One other 'dodge' tried, beneficial on Mainline J72s has been to fit spring wires pressing slightly on the top of each of the wheels. These were soldered to brass pins fitted in the split chassis plates, to apply some downward pressure on the wheels and acting as a pickup themselves. Beeman.

Edited by beeman

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Do not get why a 1N4007 diode is specified at http://members.optus...north/alive.htm as that is a 1 amp 1kv (700v rms) diode, a 1N4001 should be sufficient (1 amp, 50v, 35v RMS), seems a bit of overkill after his comments re ensuring the capacitor is right for the dcc voltage.

As they are quite often the same price why not?

I usually buy 1N4007 or 1N5407 diodes when I require a 1A or 3A diode regardless of voltage.

The cap must be the right voltage as if it is too low it will pop and I have been told that running polarised caps much below their rated voltage isn't clever either.

 

Keith

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Have asked and yes any 1A diode will do. I take the price the same issue but it would be best to specify the lower voltage one and then leave it up to the constructor to decide whether they are going to use a 4001/2/3/4/5/6/7 depending on what they have/ what they can obtain.

Edited by Butler Henderson

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Have asked and yes any 1A diode will do. I take the price the same issue but it would be best to specify the lower voltage one and then leave it up to the constructor to decide whether they are going to use a 4001/2/3/4/5/6/7 depending on what they have/ what they can obtain.

Without sufficient knowledge/experience it could be possible that someone might try to obtain a 1N4001 and find it not available and assume a 1N4002-7 is not suitable. Some suppliers don't stock the full range.

It's not unusual to see circuit diagrams with the legend "1N4000 series" suggesting any one can be used.

 

Keith

Edited by melmerby

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Diode voltages should be chosen to reflect the type of circuit. While the supply may be say 12v , a diode may have to sustain the Back EMF that occurs when an item is switched off, perhaps a relay, or worse, solenoid, both being inductive coil operated. Diodes and series resistors are often used to suppress this back emf from reaching other components. Decoders are designed and in fact use the motor back emf to monitor O/P levels. I prefer a higher value of working volts where available, considering cost/size is not a issue., . Beeman.

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I lik I like the way he says it will run onto 12" of tape and whilst all wheels are on the tape can reverse direction! Keith

 

I don't consider myself a numptie when it comes to DCC but can someone explain how the decoder gets the change direction command while all the wheels are on the tape!!! edit . Ahh, just read the description under the video, that explains it.

 

I've been playing with a DCC concepts 'Stay Alive' in a Sentinel, as far as running on strip of tape is concerned, forget it. It stops as soon as the last set of wheels hits the tape. I think the 'Stay Alive' in these decoders only refers to the decoder circuitry, not the motor, relying on the momentum of the loco to 'bridge the gap'.

Edited by tender
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I don't consider myself a numptie when it comes to DCC but can someone explain how the decoder gets the change direction command while all the wheels are on the tape!!! edit . Ahh, just read the description under the video, that explains it.

 

I've been playing with a DCC concepts 'Stay Alive' in a Sentinel, as far as running on strip of tape is concerned, forget it. It stops as soon as the last set of wheels hits the tape. I think the 'Stay Alive' in these decoders only refers to the decoder circuitry, not the motor, relying on the momentum of the loco to 'bridge the gap'.

 

The stay alive in DCCconcepts decoders won't do the party tricks that the Lenz gold and usp will IE, run over 12" of tape or paper or change directions while on the paper and drive off in direction it came from.

 

Yes, the lenz Gold + usp module does this. Don't ask me how it works it just does.

 

The stay alive on DCCconcepts decoders is only good for aprox 2 seconds but that is uaually enough to get loco over a small dirty spot. It also helps slow running.

 

Cheers

 

Ian

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The Lenz unit does it with two tricks. Firstly, huge capacitance using gold-caps. These can store more energy in a small space than the more common electrolytic capacitors. Secondly, the ability to sense the DCC signal via the capacitance and inductance in the rails, this allows it to get changes in instruction whilst driving over paper (or dirt).

 

Simpler electrolytic systems may keep the motor going for fractions of a second or even seconds, depending how much energy can be stored in the capacitors. With some decoders, the motor function will be shut down if the voltage drops below a certain level, this keeps the decoder electronics going longer on the remaining energy. With others, they will use all the energy until the voltage gets below that which will run the DCC chip, and then everything stops together.

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