Power supply

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David B
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Power supply

Postby David B » Sat Jul 16, 2011 9:08 am

Can someone please help by pointing me to a suitable power supply unit to go with a Pictroller? I will be using a hand held unit and at this stage it is mostly for a test track and short runs, not a layout.

I know it needs to be 18v AC (+/-) and deliver at least 1.5 amps. I have looked on Google and so on and, being illiterate with electrics, I am lost. Ideally, I would like a unit the equivalent of USB - Plug 'n' Play.

Thanks, chaps.

David

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Jol Wilkinson
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Re: Power supply

Postby Jol Wilkinson » Sat Jul 16, 2011 10:05 am

David,

take a look at the Gaugemaster site, they do a selection of cased PSUs, albeit expensive.

Jol

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grovenor-2685
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Re: Power supply

Postby grovenor-2685 » Sat Jul 16, 2011 2:39 pm

I would suspect that the Pictroller will be perfectly happy with a Dc supply, and these days regulated DC supplies are cheaper, lighter and more efficient than an AC transformer.
But best to confirm with the Pictroller supplier (Malcolm Smith) what voltage will be best for a DC supply. Adjustable ones are readily available as well as fixed outputs.
appropriate suppliers are Rapid electronics or Maplins.

From the former
adjustable with plenty of power: http://www.rapidonline.com/Electrical-Power/Power-Supplies/Plug-In-PSUs/36W-Voltage-adjustable-multi-output-plugtop-PSU/76992
fixed voltage, less power but cheaper http://www.rapidonline.com/Electrical-Power/Power-Supplies/Plug-In-PSUs/18W-Interchangeable-plugtop-desktop-switch-mode-power-supply/81328

from the latter: http://www.maplin.co.uk/worldwide-ac-dc-multi-voltage-3600ma-power-supply-48908 looks a good buy while on offer.

But do check with the Pictroller people that it will work on DC, the instructions only mention AC but I suspect that is just because its conventional for a model railway supply.
Regards
Keith
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Keith
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David Thorpe

Re: Power supply

Postby David Thorpe » Sat Jul 16, 2011 4:09 pm

The Pictroller instructions suggest a 14-18v AC requirement. Gaugemaster do a number of relatively inexpensive open construction transformers and if you really need as much as 1.5 amps, their T2 Model will give you 1 x 18v AC output at up to 2.5 amps for less than £20. Gaugemaster do suggest that this is really only necessary for 0 gauge, and recommend their T1 model (2 x 16v AC, but only 1.25 amps each) for 4mm scale at a similar price. Being open construction you will have to fit your own mains cable and plug, and a case might well be a desirable extra - I made my own.

DT

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David B
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Re: Power supply

Postby David B » Sun Jul 17, 2011 8:22 am

Thank you, chaps. I will contact Malcolm, Keith, and see what he says.

DT - the 1.5amps came from the Pictroller instructions.

I really must try to understand electricity but it is a complete foreign language to me. I suspect it is to a number of other modellers as well.

David

David Thorpe

Re: Power supply

Postby David Thorpe » Sun Jul 17, 2011 8:47 am

I didn't see any mention of amps on the instructions for the handheld unit, only for the more complex panel mounted unit. It may therefore also be worthwhile checking with Malcolm about the ampage requirement for the handheld just in case that's different. He might also be able to recommend a suitable power supply at the same time.

DT

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grovenor-2685
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Re: Power supply

Postby grovenor-2685 » Sun Jul 17, 2011 9:34 am

Most of the amps are to pass through to the train, but it is also necessary to have a power supply which can give enough amps to activate the controller overload cutout on a short circuit and not turn itself off first. Very few trains in the smaller scales use more than one amp these days so it is the cutout capability that is likely to be the main issue. A low rated supply may well be OK running the train, especially with coreless motors but fail on overload causing problems for the system. I would always recommend being generous with the power supply for the small extra cost involved.
Keith
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Keith
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David Thorpe

Re: Power supply

Postby David Thorpe » Sun Jul 17, 2011 10:52 am

I don't know if it's relevant, but from the Pictroller (handheld) instructions:
"If a high current (>750mA) is detected, the output is turned off and the overload LED lights."

DT

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David B
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Re: Power supply

Postby David B » Mon Jul 18, 2011 2:30 pm

I have spoken with Malcolm and a DC unit would be fine for the hand held unit. The unit is rated at 0.75 amps so really it needs a minimum of 1amp in the power supply.

Thanks for the pointers to a DC unit, Keith.

David

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David B
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Re: Power supply

Postby David B » Sun Dec 18, 2011 8:28 am

I see that Malcolm has updated his website pages for the Pictroller which now says, "The PICtroller requires a 14-18V AC or 20-24V DC power supply."

See: Malcolm's Miniatures.

David
Last edited by David B on Sun Dec 18, 2011 8:31 am, edited 1 time in total.

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David B
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Re: Power supply

Postby David B » Sun Dec 18, 2011 8:31 am

On a slightly different tack, I have an 18v AC output into which I have put a switch. I would like a visual indication that the juice is flowing and have looked for a light but cannot find anything suitable - the only items being either 12v DC or 240v AC.

Does anyone have a suggestion and how it might be fitted?

Davdi

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John Bateson
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Re: Power supply

Postby John Bateson » Sun Dec 18, 2011 9:50 am

David,
Traditional lights do not know whether they are lit up by AC or DC so calling a light 12v DC is not really the problem, it will light up with 12v AC and produce the same amount of light.

Have you considered an LED and a small resistor in series, far less likely to blow in the longer term and much cheaper. Ready wired ones are available from many places, many of them come with panel mount fittings.

John
Slaving away still on GCR stuff ...

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David B
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Re: Power supply

Postby David B » Sun Dec 18, 2011 10:36 am

Thanks, John. I have tried in Maplins (!!) and the phrase 'chocolate fireguard' came readily to mind.

I am a novice novice with electronics but had got as far as considering LEDs, though the resistor bit eludes me. I had dismissed LEDs as they all seem to run on about 4v and even I had come to the conclusion that they might explode with 18v! However, I like the idea of these things being already wired but don't know where I would get any. In actual fact, I have 4 outputs from 2 transformers and, as the wiring is a simple connecting up job, I can manage that, but the light has eluded me.

I am sticking my head over the parapet here as I know there are many others out there like me who are not only clueless, but also somewhat intimidated by the electronics aspect of the hobby. Perhaps someone else will also ask a simple question that will help beginners like me.

David

andrewnummelin
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Re: Power supply

Postby andrewnummelin » Sun Dec 18, 2011 11:18 am

Do you need to know whether power is available or whether current is actually flowing?
The first is relatively easy with a light but the second would be more difficult. The sophisticated solution would be a couple of proper meters...
You could try giving RS Components a call - its many years since last dealt with them but I always found them very helpful and their range is enormous.
Tel: 08457 201201 web site http://uk.rs-online.com/web/
Regards,

Andrew Nummelin

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David B
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Re: Power supply

Postby David B » Sun Dec 18, 2011 12:48 pm

Andrew Nummelin wrote:
Do you need to know whether power is available or whether current is actually flowing?


This is tricky. Aren't they the same? Obviously not, but you may now realize my level of expertise!

I just want the light to show whether there is power, not how much. If something goes wrong, I can check easily to see what is working.

David

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John Bateson
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Re: Power supply

Postby John Bateson » Sun Dec 18, 2011 3:51 pm

http://www.rapidonline.com/Electronic-C ... stor-29282
Or browse through the whole secion on LED indicators.

David,
Its a while since I bought such devices, but the 24v one should be alright - they are so cheap these days its worth experimenting.
Note that 18v is the average voltage (I will not complicate things further) and the peaks will be of the order 25v which should light the 24v version. Think of this in the same terms as mains voltage, nominally about 24vac but it has peaks of around 400v
John
Slaving away still on GCR stuff ...

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David B
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Re: Power supply

Postby David B » Sun Dec 18, 2011 4:17 pm

Thank you, John. This looks just the business.

David

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Ian Everett
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Re: Power supply

Postby Ian Everett » Mon Dec 19, 2011 10:25 am

"Being open construction you will have to fit your own mains cable and plug, and a case might well be a desirable extra - I made my own."

I cannot help but feel that someone who professes to being a novice at electrics who wanted a "plug and play" power supply should avoid using an open-construction transformer like the plague.

There are enough of us in the S4 Society who are approaching our three score plus ten deadline without depleting our numbers all for the want of a safe power supply!

Ian

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David B
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Re: Power supply

Postby David B » Mon Dec 19, 2011 1:46 pm

I suppose what we are coming down to is the difference between 'electrics' and 'electronics'.

Electrics is not my thing, but I find it easier than electronics where I can't even speak the language! On the practical electrics side of my power supply, I have a case and have bolted the transformers in. For the power lead I am using a kettle type lead & socket. Connecting 'A' to 'B' with a wire is straight forward & I have someone on hand to point me in the right direction & check my work. I can wire a plug, change a light bulb & even change a light switch.

Introduce things like 'resistor', 'capacitor', 'power', 'amps' and so on, then I am lost and I need someone on my shoulder as well as an interpreter. One can follow instructions - I made a servo driver board at the last Missenden weekend - but actually understanding what one is doing and why is another thing. This is where electronics becomes difficult and, as I said before, intimidating. You cannot make progress and work things out if you cannot speak the language or understand what is going on.

I know there are many more people in the same position. It is one of the reasons that in 2012, Missenden will not be running a separate electronics weekend but incorporating it in to their Autumn Weekend where modellers will be exposed to and have the opportunity to discuss and ask questions about electronics. (The details of the Missenden Autumn Weekend are still being finalized which is why the website is not up to date yet. I hope to get it done before the end of the year.)

David

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LesGros
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Re: Power supply

Postby LesGros » Mon Dec 19, 2011 3:12 pm

Hello David,
I would recommend that look at the information pages of the Maplin Catalogue; it contains simple explanations about electronic components, products, and what you need to make connections. Unfortunately, products only are indexed, but there are information panels close by the relevent components. For example, you should be able to find explanation of resistors required for use with LEDs.
It is not a substitute for an electronics training manual, but it could help you formulate the right questions, and point you in a sensible direction if you wish to pursue your curiosity.

regards
LesG

The man who never made a mistake
never made anything useful

Terry Bendall
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Re: Power supply

Postby Terry Bendall » Tue Dec 20, 2011 7:19 am

davidb wrote:Introduce things like 'resistor', 'capacitor', 'power', 'amps' and so on, then I am lost and I need someone on my shoulder as well as an interpreter. One can follow instructions - I made a servo driver board at the last Missenden weekend - but actually understanding what one is doing and why is another thing. This is where electronics becomes difficult and, as I said before, intimidating. You cannot make progress and work things out if you cannot speak the language or understand what is going on.


David is quite right, although the language can be learnt, just as we might learn a spoken language. A very long time ago, about 35 years at least, I taught a boy who was a complete duffer at craft, but who was a expert at electronics, because he was interested in the topic and had taken the trouble to learn about it. I needed to know something about the topic and since I knew that I was better at craft work than he was, I thought that if he can learn electronics then so can I. So I did.

What we need is someone with a bit more knowledge than me, and who's electronic knowledge is a bit more up to date than mine, to write a series on basic electronics for Scalefour News. Now who would be prepared to do that?

Folllowing a diagram is fine, and if what you are building works, then so much the better. It is when the thing does not work that the real learning begins.

Terry Bendall

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Andy W
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Re: Power supply

Postby Andy W » Wed Dec 21, 2011 5:04 pm

That's a great idea Terry - if someone is willing to do it. I've tried to read up on electrics, and all I've managed to glean is several migraines. I can't be alone with this "blind spot" (not the migraine!).
Make Worcestershire great again.
Build a wall along the Herefordshire border and make them pay for it.

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David B
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Re: Power supply

Postby David B » Wed Dec 21, 2011 5:24 pm

Terry wrote:
What we need is someone with a bit more knowledge than me, and who's electronic knowledge is a bit more up to date than mine, to write a series on basic electronics for Scalefour News. Now who would be prepared to do that?


Great idea, Terry. If anyone is prepared to do this, I am willing to work with them. We really do need some sort of 'Starter Pages' for electronics.

David

doktorstamp
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Re: Power supply

Postby doktorstamp » Thu Dec 22, 2011 5:59 pm

http://www.brian-lambert.co.uk/


The above is a website that may be known to some members. I believe he is a member of EMGS, though not certain.

A number of his pages show not merely the circuit diagrams, but also the practical application, which can often differ widely from the aforementioned circuit diagram. If I recall correctly he has recently written a book on the subject of model railway electronics.

kind regards and seasonal greetings

Nigel

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dcockling
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Re: Power supply

Postby dcockling » Thu Dec 22, 2011 6:22 pm

We have a Brian Lambert in the Scalefour Society, not a member of the forum, but I don't know if it's the same Brian Lambert.

All the Best
Danny


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