Return-Path: X-Spam-DCC: paranoid 1102; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_MESSAGE autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tATA62Zx030437 for ; Sun, 29 Nov 2015 11:06:02 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a2yp1-00076h-8S for rs_out_1@blacksheep.org; Sun, 29 Nov 2015 10:03:07 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a2yp0-00076Y-SO for rsgb_lf_group@blacksheep.org; Sun, 29 Nov 2015 10:03:06 +0000 Received: from mail-wm0-f45.google.com ([74.125.82.45]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1a2yo4-0002xA-0G for rsgb_lf_group@blacksheep.org; Sun, 29 Nov 2015 10:03:05 +0000 Received: by wmuu63 with SMTP id u63so96527617wmu.0 for ; Sun, 29 Nov 2015 02:01:50 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:content-type:message-id:mime-version:subject:date:references :to:in-reply-to; bh=IHrPq5OgRVuNwZpZhQdWmsPqnZ3gprfgRZJYdheKJB8=; b=NfxfZuIw2+aaCAsCb/BMV8dQiN0Ip4NESMF2iGsl1PVG2Dg8ZP2tBDkAAFtbAtAaBG SrnA1FRyNuuOn2PdyN6dbxDlBFkwC+m8BoWIts7TteTV39JrqmWEGM65O648IMT9YRVv 1sYRV+TdeCJDnR7cYRqDEOs873G2kgBtf8zCdsHakKe2FQrRs67Mrl9bwIQhgZVqJy5J of4kLJHIrlgH86ECDfB4nkvmSiUPzRjOjBXbegHYK2NdzPf+XGppMtTmvq/bESWpB6Ui LuNhLpUi5fzeoUQm3IVxYu+ONBZHbwIVhG0ESCFR03OYqK0aPa/ZOyuCF7zmWWGOnNgS NCyA== X-Received: by 10.28.182.134 with SMTP id g128mr21945087wmf.95.1448791310584; Sun, 29 Nov 2015 02:01:50 -0800 (PST) Received: from [192.168.1.101] ([82.98.23.94]) by smtp.gmail.com with ESMTPSA id d66sm16042933wma.21.2015.11.29.02.01.49 for (version=TLSv1/SSLv3 cipher=OTHER); Sun, 29 Nov 2015 02:01:49 -0800 (PST) From: John Rabson Message-Id: Mime-Version: 1.0 (Mac OS X Mail 9.1 \(3096.5\)) Date: Sun, 29 Nov 2015 11:01:47 +0100 References: <56587F40.5070709@posteo.de> <87FFCE57-D2D7-4616-B5E8-B84CD819C685@talktalk.net> <5658E894.6090208@posteo.de> <82B8809C-36E5-4731-8A4B-002BD4465B12@talktalk.net> <5658EE97.2020107@posteo.de> To: rsgb_lf_group@blacksheep.org In-Reply-To: X-Mailer: Apple Mail (2.3096.5) X-Scan-Signature: 85c54099682e8e65d9e25bf804a68673 Content-Type: multipart/alternative; boundary="Apple-Mail=_503F164E-9A55-422E-BD26-EC82ABB2D76F" Subject: Re: 3 phase (was LF: G3KEV) X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 5421 --Apple-Mail=_503F164E-9A55-422E-BD26-EC82ABB2D76F Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 This sounds like the sort of thing that the electricity company got up = to in the Suffolk village where I lived for years. There were three = feeds to the village: one from the north which fed half the main street one from the south which fed the other half one from the east which fed a side road. This was derived from what was = known as a =E2=80=9Cfarmer=E2=80=99s line=E2=80=9D, being a single phase = transformer connected to 2 phases of the local three phase higher = voltage system, with a 480 V centre tapped secondary In the middle of the village was a distribution pole with a prominent = notice =E2=80=9CWarning! These LV systems will NOT parallel=E2=80=9D. I = asked one of my colleagues what this meant and was told that the phasing = of the farmer=E2=80=99s line was such that it was not possible to get a = 0=C2=B0 phase difference between it and the other supplies. Before the higher voltage line plant was upgraded, it was common in the = middle of a cold winter night for one third of the village to be off = supply (but not predictably which third). I notice DK7FC says that domestic three-phase supplies are common in = Germany. In both England and France the authorities do not like such = arrangements and do their best to phase them out. The supply to our = property was probably three-phase at some stage because the official = fuse unit has had a notice stuck on it emphasising that this = installation is now single phase. John F5VLF > On 29 Nov 2015, at 10:42, Andy Talbot wrote: >=20 > If you use two transformers on a 3-phase supply, with the primary = windings in a SQRT(3) ratio, one connected in delta, and one in star = across the supply; equal value secondaries when rectified will give you = 12X ripple instead of the 6X normal achieved though full wave 3-Ph = rectification. >=20 > Unfortunately SQRT(3) is not rational (becuz Euclid sez so!) so any = turns ratios will be approximate, hence ripple will be degraded = marginally >=20 > 'jnt >=20 john.rabson07@gmail.com Researching history of RABSON, BLACKSHAW, GAUNTLETT, VERLANDER and = ROBSONNE --Apple-Mail=_503F164E-9A55-422E-BD26-EC82ABB2D76F Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 This sounds like the = sort of thing that the electricity company got up to in the Suffolk = village where I lived for years. There were three feeds to the = village:

  • one from the north which fed half = the main street
  • one from the south which fed the = other half
  • one from the east which fed a side road. = This was derived from what was known as a =E2=80=9Cfarmer=E2=80=99s = line=E2=80=9D, being a single phase transformer connected to 2 phases of = the local three phase higher voltage system, with a 480 V centre tapped = secondary

In= the middle of the village was a distribution pole with a prominent = notice =E2=80=9CWarning! These LV systems will NOT parallel=E2=80=9D. I = asked one of my colleagues what this meant and was told that the phasing = of the farmer=E2=80=99s line was such that it was not possible to get a = 0=C2=B0 phase difference between it and the other supplies.

Before the higher = voltage line plant was upgraded, it was common in the middle of a cold = winter night for one third of the village to be off supply (but not = predictably which third).

I notice DK7FC says that domestic three-phase supplies are = common in Germany. In both England and France the authorities do not = like such arrangements and do their best to phase them out. The supply = to our property was probably three-phase at some stage because the = official fuse unit has had a notice stuck on it emphasising that this = installation is now single phase.

John F5VLF

On 29 Nov 2015, at = 10:42, Andy Talbot <andy.g4jnt@gmail.com> wrote:

If you use two transformers on a 3-phase supply, with the = primary windings in a SQRT(3) ratio, one connected in delta, and one in = star across the supply; equal value secondaries when rectified will give = you 12X ripple instead of the 6X normal achieved though full wave = 3-Ph rectification.

Unfortunately SQRT(3) = is not rational (becuz Euclid sez so!) so any turns ratios will be = approximate, hence ripple will be degraded marginally

'jnt


john.rabson07@gmail.com

Researching history of RABSON, BLACKSHAW, GAUNTLETT, = VERLANDER and ROBSONNE




= --Apple-Mail=_503F164E-9A55-422E-BD26-EC82ABB2D76F--