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Hi all,

I bought a Zephyr recently. Because I imported it from the US to the UK, I bought it without the US-spec power supply. So I needed to find out how to connect my own power supply. For the benefit of anyone else who does this, here's what I learnt:

Power input socket:
  • the input requires 15V (rms) AC 50/60Hz (must not exceed 16V rms)
  • alternatively, 18V DC may be used (must not exceed 22V DC)
  • the supply requires up to 2.5A to meet the full capability of the Zephyr.
  • the connector is 5.5mm dia. (outer), 2.0mm dia. (inner)
  • for a DC supply, the centre pin is positive, the outer conductor is negative.
Rick
 

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QUOTE the supply requires up to 2.5A to meet the full capability of the Zephyr
As a hobby builder (see my power supply) and non- electrician, I often wonder about current and volts.

Does it matter if the transformer supplies more amps than the device needs?

The device is rated for a certain power requirement - it only takes what it needs - right?

Do excess amps do any damage?
 

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QUOTE (Doug @ 21 Dec 2006, 23:25) <{POST_SNAPBACK}>As a hobby builder (see my power supply) and non- electrician, I often wonder about current and volts.

Does it matter if the transformer supplies more amps than the device needs?

The device is rated for a certain power requirement - it only takes what it needs - right?

Do excess amps do any damage?

A unit will only draw what current it needs so excess capacity isn't an issue in normal running conditions.

HOWEVER if a fault occured and the fail safe didn't blow (i.e. the fuse or cutout trip) then the unit could draw far more power then is required doing some damage or burning out the unit completley.

Darren
 

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Doug - that's a very well made looking power supply & you seem to have taken good care of protection indeed.

As an electrical engineer (who does a fair amount of Portable Appliance Testing) I just wish more people would take the sort of care that you have. Sometimes, when I am at exhibitions I have to have "selective vision" & just remind myself on why I am there. Many of the mains electrics I see would fail on the basic visual.

As an aside I have been asked by a number of clubs/societies to test their mains equipment, but I am not too keen because of the possible reactions of some people. As an example, last week I tested 2 model railways being used in a cinema projection room & failed both of them for exposed mains transformers & terminals under the baseboards & the owner/builder was a friend of mine !

In my opinion, it's only a matter of time before venue owners/operators insist of P A Testing. Many venues already insist on everyone using a "circuit breaker".
 

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QUOTE (darobi @ 22 Dec 2006, 18:26) <{POST_SNAPBACK}>A unit will only draw what current it needs so excess capacity isn't an issue in normal running conditions.

HOWEVER if a fault occured and the fail safe didn't blow (i.e. the fuse or cutout trip) then the unit could draw far more power then is required doing some damage or burning out the unit completley.

Darren

My digitrax manual recommended that any power supply for the Zephyr be limited by a fuse or circuit breaker to 3 amps.
Apologies for resurrecting an old post :^)
 

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QUOTE In my opinion, it's only a matter of time before venue owners/operators insist of P A Testing. Many venues already insist on everyone using a "circuit breaker".
I had a circuit breaker installed in my garage where I'm building my new layout for safety reasons.
 
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