From: John Woodgate
Subject: Re: Howto: Low current PS without a transformer
Date: Thu, 14 Nov 2002 08:45:44 +0000
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Thu, 14 Nov 2002 11:09:23 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Ban wrote
(in ) about 'Howto: Low current PS
without a transformer', on Thu, 14 Nov 2002:
>The single phase mains tolerances in continental Europe(incl. Norway) are:
>Voltage 230 volts AC RMS +10% / - 6%
>Mains Frequency 50.00 Hz +/- 0.2 Hz
The +10/-6% applies to Great Britain, which was on 240 V. The north of
Ireland was on 230 V before harmonization and stays at +6/-6 % AFAIK.
For Continental countries, that were on 220 V, the range is +6/-10%.
>You are not allowed to connect any appliance galvanically coupled(=without
>transformer with separate isolated windings) to mains, which doesn't meet
>very rigid specs.
Well, 'not allowed' is a bit vague, but it's true that such devices are
subject to very stringent safety requirements.
>Only certified people(electrician, EE) are allowed to do these kind of
>things. Inform yourself about the rules in your country, if you have an
>accident the insurance might not pay (for your funeral).
That is certainly not true in UK, YET. It is proposed to make new
regulations that would have that effect in many cases, e.g. a PIR
security luminaire, which typically use such direct-on-line low-voltage
supplies, will only be allowed to be fitted by a technician, not even a
Chartered Electrical Engineer, unless he also has a technician's
It won't apply to light organs, with mains plug connection, which also
use DOL low-voltage power supplies
>As an hobbyist just stay away from mains, use a ready-made wall wart and do
>your low voltage circuits.
That is the best advice, indeed.
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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