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Ian Wigglesworth
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Discussion Starter · #1 ·
Hope some one can explain this.

I've been looking at buying the powercab and after playing about with one really liked it.

The problem I've noticed is if you get short for whatever reason the powercab LCD will switch off.
That I can understand, clear the short everything runs as normal, the cab will control the loco.

PROBLEM:- the LCD screen just shows the top line with loads of letters and characters scrolled across it.
The only way to reset this is by removing the transformer from the mains supply waiting a few seconds then plugging it back in.

Sent email to NCE who have said that this is normal???(first reply said it wasn't!)
They have now said connect a car bulb in circuit with the feed wires that goto the track, if there is a short for whatever reason it should stop the transformer shutting down and hence not loose the LCD screen.(car bulb 12VDC but AC to track, is this correct?)

Where abouts would this bulb be wired, and will it work?

I think it maybe the supplied transformer, just can't handle a short circuit.
The instructions do say that a regulated 10-15VDC less than 3amp power supply can be used, the one that is supplied is a US type (13.5Vdc 1.1amp) so I have to use a 2pin adapter plug.

Could be just get a better transformer?

Any thoughts

Ian
 

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It sounds like the microprocessor in the NCE power cab is either being reset or going off into "the long tall grass". Either way it appears you are having to perform a cold start on the system to recover from the short and suggests a less than perfect design.

>(car bulb 12VDC but AC to track, is this correct?)
As I understand it, light bulbs don't care which way the electrons are flowing, so long as they flow, the element will heat up and a small percentage of the energy will be given off as light; the rest is heat. I remember building an electronic controller (using a thyristor if I remember correctly) and it used a car light bulb as the overload protection. Unfortunately I cannot remember how you wire it into the circuit. I am sure someone else here will know.

David
 

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Ian Wigglesworth
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Discussion Starter · #3 ·
From what I've been told, It is the design the excuse is you can't expect everything for the price!!

Hey ho, I know that once all of the points have been motorised I shouldn't get any short circuits, but you always have the chance of a derailment to cause a short.

I haven't got that much cash to buy a controller and all the point motors and accesory decoders as well!! thought I could get it piece meal.

A friend is selling a ZTC control anybody used one what do they reckon?

They look quite good wouldn't buy one new at that price though.

Ian
 

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>From what I've been told, It is the design the excuse is you can't expect everything for the price!!
It's an interesting design choice - "We'll save money on having recoverable short circuit protection and have these extra buttons instead." Still the market will decide. If enough people think that having to pull the plug out of the wall for five seconds is not an acceptable solution, they will stop buying.

>I shouldn't get any short circuits
but it doesn't mean you won't. Gary's new blog illustrates what can happen if you just "switch over" from DC without considering how you might locate a short if you get one.

>I haven't got that much cash to buy a controller and all the point motors and accesory decoders as well!
I would say very few people do. I am starting with a control unit and one loco decoder and will work up from there.

>A friend is selling a ZTC control anybody used one what do they reckon?
Why is he selling: moving house, leaving the country, going 3 rail? If he hasn't got a convincing reason for the sale, you have the answer to your question.

David
 

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QUOTE (dwb @ 25 Sep 2006, 22:23) <{POST_SNAPBACK}>>(car bulb 12VDC but AC to track, is this correct?)
As I understand it, light bulbs don't care which way the electrons are flowing, so long as they flow, the element will heat up and a small percentage of the energy will be given off as light; the rest is heat. I remember building an electronic controller (using a thyristor if I remember correctly) and it used a car light bulb as the overload protection. Unfortunately I cannot remember how you wire it into the circuit. I am sure someone else here will know.

Wire it in series with one of the wires to the track (doesn't really matter which). Under normal conditions the current is too low to heat up the filament, the bulb doesn't glow and its resistance is quite low. When you get a short the current is enough to light the lamp, its resistance increases and limits the current.

Andrew
 

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If you have a prolonged short circuit with the PowerCab it will just cut out and power will be restored after the cause of the short circuit has been resolved. This is not unexpected as the PowerCab is just a starter system and doesn't have extensive inbuilt protection against short circuits, unlike the powerPro which does. It does highlight the usefulness of circuit breakers which can.

a. protect (relatively expensive) controllers against short circuits, and
b. allow unaffected parts of the layout to continue to operate.

The NCE EB3 circuit breaker, for example, provides short circuit protection for up to 3 power districts with the trip current of each power district being adjustable.

This does not mean PowerCab will be harmed by a short circuit, it's just that the PowerCab itself controls the power to the layout - without the throttle the system will have no power. So, when a short occurs the PowerCab just cuts out. If the short is on the programming track then SHORT DETECTED is displayed on the handset. Short circuits on any layout are to be avoided if possible, but especially on DCC layouts.

I have a power cab and it's a superb system and I have experienced no problems in the time I have had it, programming is such a doddle with this system, it really is dcc made easy, I have previously owned a ZTC 511 which was a very brief experience (absolute nightmare and bloody expensive!!) and I chopped it in for a Lenz Set 100, the Power Cab IMO is one of the best sets out there lots of upgrades coming for it soon and at £95 you can't go wrong.
 

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Ian Wigglesworth
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QUOTE (37197 @ 26 Sep 2006, 13:56) <{POST_SNAPBACK}>If you have a prolonged short circuit with the PowerCab it will just cut out and power will be restored after the cause of the short circuit has been resolved. This is not unexpected as the PowerCab is just a starter system and doesn't have extensive inbuilt protection against short circuits, unlike the powerPro which does.

Thanks for the information!

I understand that the powercab will just cut out, when there is a short, clear the short and it does restore power.

The only problem I found was the powercab wouldn't reboot correctly once the short had been removed.
You remove the short and you have full control but the LCD screen was all scrambled with random letters., across the top line.

To clear the screen and get it back you need to remove the power supply.

Ian
 

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DT
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Tony's Train Exchange produces a great circuit breaker for one, two or four power districts. Product info here.

- Automatic re-close of the breaker after 1 second (or manual re-close option)
- LED indication of direction and trip conditions (plus provisions for a remote LED)
- Exclusive over voltage feature protects decoders burn out from DCC booster melt down
- Over current trip time adjustments using jumpers
- All solid state design, including power switching elements, for fast, reliable operation
Note: Not for direct current (DC) applications. Not compatible with EasyDCC 3Amp Booster which has premature short circuit response.

This circuit will trip before your controller is shut down. I have the Auto reverse circuits they produce and they work flawlessly. Very good value for money and excellent quality.
 

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QUOTE (wiggy25 @ 26 Sep 2006, 19:23) <{POST_SNAPBACK}>The only problem I found was the powercab wouldn't reboot correctly once the short had been removed.
You remove the short and you have full control but the LCD screen was all scrambled with random letters., across the top line.

To clear the screen and get it back you need to remove the power supply.
Ian

The only thing I can suggest is there must be a problem with that particular cab, mine just goes blank and re-boots again within a few seconds once the short is sorted.
 

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Ian Wigglesworth
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Discussion Starter · #10 ·
I wish it was just that one cab!

This is my fathers controller, I sent an E-mail to NCE who said " no, thats a fault with the cab send it back for replacement or repair"
As the powercab was only about 1 month old my father went back to the shop he bought it from, the guy tried all 30 POWERCABS only 1 didn't scramble the LCD display!!!(So he gave this one to my father)

He then contacted NCE himself and went mad at them saying he had 30 cabs that didn't work and he had a an exhibition that weekend with nothing to sell, etc...

Next thing I know Customer support from NCE tell me they got it wrong and it will need the power removing to reset the LCD screen!!!!

But I've since spoken to a number of people who's LCD screens reboot correctly when a short is cleared!!

MMmmm something is not quite right somewhere!!!

I just want someone to be honest and if NCE have found a fix then great, but it would be nice for them to tell me!!

Ian
 

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I can think of two possibilities:-

1) A new model of LCD is being used in this recent batch of PowerCabs and they have a different power on / reset characteristic to the previous model.

2) The firmware** in this recent batch of PowerCabs has been modified and during this process the reset sequence for the LCD no longer brings the screen back to life.

It would be interesting to know if the PowerCab you got that did work is from a previous batch - eg older serial number or manufacturing date.

Do remember this is an educated guess based on my experience of developing these kinds of systems and the few facts relayed in the previous post. I might be wrong.

David

**firmware is the term for a software program stored in semiconductor memory in a device.
 

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Ian Wigglesworth
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Discussion Starter · #13 ·
Thanks.

I've been thinking along the same lines!

Seems very strange that the guy that had all these powercabs couldn't tell what batch they were from as there was no serial number on the boxes!

Without opening every box and checking every serial number it's hard to tell whats going on.

My belief is that NCE have indeed fitted the newer powercabs with updated firmware, maybe a different LCD to prevent this fault.

When the guy who sells them finds out there could be a problem and speaks to NCE, they say no they are fine thats how they work ( on the quiet they say we have now introduced a solution to prevent this!!) but the older models all did this so there is no problem.

Honesty would be really good here, I would buy the Powercab as it is a fantastic bit of kit for the money, BUT I will wait for the local supplier to get the latest stock and hopefully this would not have the fault.

For NCE to send me two different E-mails contradicting each other was some what daft.

I'm now thinking shall I go for a different manufacturer, so I don't have to keep power cycling the unit to reset the LCD.

Madness

Ian
 

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>I'm now thinking shall I go for a different manufacturer
The old adage "Never buy version 1.0" applies. I am sure that NCE will solve the problem. It all depends on what they will do to support the existing units in the field.

Mind you I am not going to follow the adage. I am determined to get an ECoS just as soon as they land (or as soon as my bank balance will permit). ESU have set up a german language support forum, so hopefully the locals will find all the problems before the export models get shippped. Still all is not lost, the ECoS is designed to be "user upgradable" via the network port.

David
 

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The quote above by 37197 (which isn't acknowledged but is actually taken verbatim from a post I made on another forum) states the solution - you shouldn't rely solely on any controller to detect and resolve short circuits, especially entry level systems. Circuit breakers are there to do exactly the job you require - detect the shorts and stop these affecting the controller. They have already provided the solution with their EB3 circuit breaker. Why should NCE spend vast amounts of time and resouce developing a solution to a problem when the solution already exists?

No doubt this will provoke a number of responses!

Regards

John R
 

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QUOTE (BromsMods @ 29 Sep 2006, 21:13) <{POST_SNAPBACK}>- you shouldn't rely solely on any controller to detect and resolve short circuits, especially entry level systems.
Why not --- other entry level systems (such as my now aging Compact) do a perfectly good job of detecting shorts. Circuit breakers are more appropriate for dividing up a larger layout so that a short in one area doesn't stop running elsewhere.
 

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>No doubt this will provoke a number of responses!
Indeed. An entry level system should be a one box solution. There is a enough trepidation about "going digital" without adding extra boxes and connections into the equation.

David
 

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Ian Wigglesworth
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Discussion Starter · #18 ·
Well I've bought it all!!

Got the NCE Powercab and the Lenz LS150 6 way point decoder.

All working great.

Have connected the 12v 5watt bulb in series to the track works perfectly. If there is a short the bulb just lights up, the LCD screen on the cab doesn't go off at all.
Just have to clear the short and away we go.

The only problem I do have is on the points, I'm using a 1amp power supply to power the LS150 this is fine switching only 1 point. When setting up a macro to switch 2 or more points there is just not enough power.

Two options here buy another power supply (maximum of 45VA 15v AC-3amps found one for £30) or try and use a CDU.

I have looked around the web but can't find a circuit diagram of how to connect the CDU to the points using a decoder. Well I have but it's using a decoder that has a DC output.
The output of the LS150 to the point motors is AC, the output of the CDU's I've seen is DC.

Any suggestions would really help.

Ian
 

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A few thoughts:-

1) Can you program the LS150 so that the points fire sequentially? This will allow the power supply time to recover.

2) Can you find a CDU design where you use the output from the LS150 to "trigger it" to drive the point rather than directing the CDU output through the LS150 which as I write it, sounds like a bad idea? I am thinking of the idea where you use a small signal to switch a large current via a relay or drive transistor.

3) I did a lot reading about Lenz modules when I thought I was going down the Lenz road. I seem to remember that the "flavour" of current which appears at the outputs is dependent on what you feed in through a particular set of terminals. I may not be correct or I may be confusing the LS150 with the module that has feedback sensors.

David
 

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Ian Wigglesworth
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Discussion Starter · #20 ·
It just says the output is AC.
Maximum input is 16vAC 3amps.

The output is about 1volt less than input.

They do fire sequentially anyway, you can set the pulse duration, but no way of setting a delay between each output. I've tried putting one point motor onto output 1 and one onto output 6.
This should give the maximum time, I think; but as there are no other points in between then it may not make any difference


Thats all there is. I was thinking about using some sort of relay which is switched by the decoder this in turn will close the circuit so the CDU can operate the point motor.

Not too difficult, or is it? but by the time I've bought relays and all the other bits, I may as well buy the 3amp power supply!
I would need 2 CDU's for each LS150 (I have 2) then relays with a 16volt ac coil low power. The two CDU's would be about £20 for high power ones. Will have a look for relays now me thinks.

Don't want to buy another power supply and then find when I get to switching 5-6 points it's still not strong enough!

Ian
 
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