"NT" wrote in message
...
On Sep 21, 5:57 pm, "Tim Walters" wrote:
"NT" wrote in message
...
On Sep 21, 2:12 am, "Tim Walters" wrote:
"NT" wrote in message
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On Sep 20, 5:24 pm, "Tim Walters" wrote:
"NT" wrote in message
...
On Sep 20, 11:22 am, "Tim Walters"
wrote:
"NT" wrote in message
...
On Sep 19, 2:11 pm, "Tim Walters"
wrote:
"NT" wrote in message
...
On Sep 15, 7:59 pm, "Tim Walters"
wrote:
Hello. My parents have got an ancient Smiths timer which
controls
some
outside lights. At the moment, no matter how the timer is
programmed,
the
lights are on all the time, unless the timer is actually
switched
off.
Dad
used to fiddle with it and, miraculously, it did what he wanted.
Now,
for
some reason, it won´t.
The timer has an override button on the left. Then there's a row
on
three
buttons (hours, minutes, and set). Then there´s a vertical
slider
with
S
at
the top and N at the bottom. There's a window above the buttons
where
the
time appears.
Thanks for any suggestions.
crikey, dont give us anything to work on. Get a multimeter, open
the
timer and see whats going on.
Ok. There are three screw-type contacts (like the ones inside a
standard
3-pin plug). One is labelled COM, the other teo are labelled L1
and
L2.
(There´s actually a mirror-image arrangement on the other side of
the
timer
but these are all dead.) There are only two wires - black and red.
The
red
goes into the COM and the black into L1. After taking the back
off,
I
could
see three small cylinders connected to the contacts. A black burn
mark
showed that something had burnt out. I took the thing down to a
local
electrical supplies wholesale shop and showed it to a very
competent
guy
there. Getting a new timer wasn't an option because the ones that
work
with
just 2 wires are limited to four hours. Getting a new programmable
timer
would mean re-wiring the system.
The guy suggested I try putting the black wire into L2, and maybe
I
would
have to reverse program the thing (on = off and vice versa). I
tried
this
but it didn't work. The lights stay on when the timer itself is
switched
on.
The difficulty is I'm not completely sure how to program the thing
in
the
first place. For instance, what do N and S mean on the slider?
What
exactly
is the purpose of the Override button?
Can anyone suggest anything?
that the use of L2 hasnt worked indicates something more serious
than
a fried switch contact (the most common cause). However, I'll say
this
once again: we cant possibly fault find it without knowing the
details
of how it works, blind, remotely, and without being able to test it.
Either fault find it yourself, or as you cant, at the very least
post
a bunch of pics so we've a clue what type of timer it is.
Here are 3 pictures. I hope they're good enough.
http://www.eurotrad-traductores.net/...www.eurotrad-t...
Thanks
Great. So
1. its a digital timer
2. the power ratings indicate its almost certainly triac switching,
not relay
3. the black patch on the pcb should have a fried component on the
other side - it would be usful to get a pic of the whole of that
board, component side.
4. Since this is a triac switcher, the using the L2 trick wont work.
Here are three shots of the underside.
http://www.eurotrad-traductores.net/...www.eurotrad-t...
"Not Found
The requested object does not exist on this server. The link you
followed is either outdated, inaccurate, or the server has been
instructed not to let you have it."
That's odd. I uploaded thse in exactly the same way as the first lot.
The
links work fine for me. I see they got bunched together. Could that be
it?
yes 
I didnt look.
Separating them...
http://www.eurotrad-traductores.net/P1010116.JPG
http://www.eurotrad-traductores.net/P1010117.JPG
http://www.eurotrad-traductores.net/P1010118.JPG
Looks like those resistors form part of a rectifier and reservoir cap
supply, and excess current has flown causing them to fry open circuit.
So you need to fix the problem and replace the Rs, preferably with
slightly higher power rated ones. Or maybe there's no other circuit
problem, only inadequately specced Rs. Going to be fun working out
what value they should be.
I've never soldered anything before but I'll give it a try. I'll let you
know how I get on.
Thanks a lot for all your help. Much appreciated.
Tim
First you'll need to practice for an afternoon first, soldering is a
skill. Secondly those will most likely be soldered in using HMP
solder, for which HMP solder and an HMP iron is needed. If you don't
want to go the hmp route, follow the tracks on the PCB and solder to
another pad further along with ordinary lead solder (electronics, not
plumbers) and connect to your Rs using some other type of connection.
But you need to work out what value resistors you need first.
Very strange. I took the timer to an electronics store and the guy behind
the counter tested all the components and says they're ok. (He knows zilch
about timers but a lot about circuit boards.)
So, we've got a timer apparently in working order, and outside lights that
work, but when you try to programme the thing, the lights stay on all the
time.
What now?