We have a clock that has a synchronous motor that is intended to run on 50Hz
mains. It skips 5 or 10 minutes fast sometimes. I looked up this problem and was
advised that noise on the power supply could cause the clock to be wrong (but
only by a tiny amount). Before I taking the clock apart, I decided to plug my
power measuring device in to the power point, and got a reading of 158 volts and
32 Hz. It is supposed to be 237 v and 50 Hz!
Since the clock had been plugged into the power point for over 30 years I pushed
the plug in and out a few times and got the correct readings. I think there was
corrosion in the contacts.
However the clock still keeps skipping ahead. The minute hand keeps in step with
the hour hand so I don't think the hands are slipping.
The clock has earlier had an accident where it fell off the wall 3 metres onto
to a concrete floor. The adjustment spindle at the bottom broke off, so I made a
new part on the huge lathe out of a 1/4'" bolt turned down to 1/16" on the
lathe. I am amazed that it didn't break!
I now suspect that a cog in the clockwork is skipping teeth. So that is next
weekend''s job, unless anyone has brilliant suggestions. I think I need a lathe
100 times smaller now that I seem to be fixing so many clocks.
I have uploaded pictures of all this but they seem to have vanished. I cannot
see where to put my user name and password. So this probably won't work!
Usually such clocks keep very good time long term although they can be
very slightly slow in the evening and fast in the early morning as mains
50Hz is guaranteed as a long term average but is load dependant.
I suggest you throw away your power tester then.
Anything outside of 50+/-1Hz and 230+/-15 would be very unusual.
Skipping ahead is unusual. Can you tell if it happens when the minute
(and/or hour) hand is on its way down the face? ie gravity assisted.
The bump might well have taken something out of alignment or chipped a
tooth. Whenever I have had trouble with synchronous motor clocks it has
been running slow or stopping because of worn teeth on the gears.
One thing I would also check is the actual wire fixings in the point its
plugged into. I've had funny things going on on clock points in the past
with daft measurements, and the wires under the screws on one half or the
other had worked loose and since there was not much current, the arcing did
not weld it together or set fire to the house!
This newsgroup posting comes to you directly from...
I quite like the synchronous electric clocks, usually in Bakelite and
really not expensive for a "collectible" but useful item.
They can be a pain to get restarted though, not sure if this is down to
sticky oil or grease on the gears ?
I usually earth them when rewiring.
All I remember of them was they usually got noisy with age. And not a
Do have a couple of mains clocks here - but they're LED. One in the
bedroom - large digits so easy to read even at my ripe old age.
*I can see your point, but I still think you're full of shit.
Dave Plowman firstname.lastname@example.org London SW
Or throw the whole thing away and replace it with a radio controlled
one? I picked up one in a CPC sale several years ago and IIRC it's only
needed a couple of battery replacements since. Saves faffing around at
clock change time.
My advice is to ditch Home owner club and use a real usenet client and use
Dropbox for your pictures and paste the public link in with the trailing 0
set to a 1.
I won't see it, but most will, and many people here won't reply to Home
owners club Usenet exported messages due to their portal software being
I would say about your clock yes well clocks do wear out and missing or worn
teeth are a fact of life. Another common one is they suddenly start going
backwards, due to the motor stalling due to damaged gears and then starting
up the wrong way. The little ratchet kicker that normally stops this does
have a habit of not working if its been in a greasy kitchen for a few years.
Why not treat yourself to a nice radio controlled clock?
This newsgroup posting comes to you directly from...
replying to Brian Gaff (Sofa 2), MattyF wrote:
I think the clock has suffered from its fall. The second hand appears to be
loose and may sometimes be touching the other hands (but never when I am
watching it). If I can't fix it easily someone can buy a new clock. But it is a
I have recently fixed the clock outside by the tram stop. It needs to be wound
every 7 days. It was stopping because of rust on the two mainsprings. That was
probably why the other two clocks stopped working.
I found Tim's message on HomeOwnersHub, and this seems easier than Usenet that
died on me 5 years ago.
On Friday, November 8, 2019 at 6:14:06 PM UTC+13, MattyF wrote:
Hi Matty, great to see you back here. We new more real DIY and less politic
Regarding HOH, it really is an abomination. It only exists to generate inco
me for the site owner, not to provide a useful service. There are so many t
hings wrong with it I'm not sure where to start.
If you don't want to use a dedicated usenet client, google groups is better
than HOH, but a proper newsreader is the best option. I believe Thunderbir
d is supposed to be okay. Plenty of free news servers like Eternal Septembe
r if you don't want to pay. Anyway, here's the link to this thread in googl
Many thanks for the tour earlier this week! I love places like MOTAT and it
's always interesting to put a face to a name on the internet. Currently in
On Wednesday, 6 November 2019 09:44:05 UTC, MattyF wrote:
A bad contact would explain the low v reading, but 32hz means your tester is basically junk, at least as far as measuring f goes.
I've had a simlar experience with a 1970s quartz clock, very puzzling. No idea what's causing your problem.
Most regulars here have the website you're using blocked. Google groups is vastly better, much as it gets criticised. And re pic uploads, please use anything other than dripbox, it's so awful I frequently just don't bother to look.
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