My grandmother's door bell stopped working (one that's mains powered,
via a "hard of hearing" box which also makes a series of lights flash in
her house), so I bought a new "mains powered" 8V bell from B&Q. It
doesn't work properly though; it rings once when you press the button
in, and once again when you release it. I'm guessing the bell wants AC
but is getting DC. It doesn't say on the packaging or the instructions
whether it wants AC - only "8V 1 amp". Are most mains powered bells AC?

The old one was designed to be battery powered by two 1.5V "D" batteries
and the electrician who fitted the "hard of hearing" box and flashy
lights just replaced the batteries with a cable from there, so I guess
it could have been more than 3V and it burned out after a few years.
Sadly I can't find my multimeter to see what it's actually outputting.

alex.

--
Alex Meaden
Technical Support Officer
Computing Service
remove "+nospam" from address to email

In article ,
says...
It
doesn't work properly though; it rings once when you press the button
in, and once again when you release it.

Errr... that's what a doorbell often does... "Ding Dong!" ??

Why do you think that's wrong :-(

Alex wrote:

My grandmother's door bell stopped working (one that's mains powered,
via a "hard of hearing" box which also makes a series of lights flash in
her house), so I bought a new "mains powered" 8V bell from B&Q. It
doesn't work properly though; it rings once when you press the button
in, and once again when you release it. I'm guessing the bell wants AC
but is getting DC. It doesn't say on the packaging or the instructions
whether it wants AC - only "8V 1 amp". Are most mains powered bells AC?
snip

You want a bell that rinnnnnnnnnnnnnngs continously when the supply is
connected. Take that ding-dong bell back....

BTW Your sig is a bit weak and might work against you in newsgroup
posts. I'm not sure I'd have a TSO in my office who couldn't work out
situations like the above. I don't mean to patronise... but....

:-)

--
Adrian C

Adrian C wrote:
You want a bell that rinnnnnnnnnnnnnngs continously when the supply is
connected. Take that ding-dong bell back....

No, it IS that kind of bell that I bought, but it doesn't work that way
when connected to (I think) DC. It's far too quiet to be a "chime" kind.

BTW Your sig is a bit weak and might work against you in newsgroup
posts. I'm not sure I'd have a TSO in my office who couldn't work out
situations like the above. I don't mean to patronise... but....

The question was really whether they tend to be AC powered or not. It's
the right kind of bell otherwise.


--
Alex Meaden
Technical Support Officer
Computing Service

"Alex" wrote in message
...
My grandmother's door bell stopped working (one that's mains powered, via
a "hard of hearing" box which also makes a series of lights flash in her
house), so I bought a new "mains powered" 8V bell from B&Q. It doesn't
work properly though; it rings once when you press the button in, and once
again when you release it. I'm guessing the bell wants AC but is getting
DC. It doesn't say on the packaging or the instructions whether it wants
AC - only "8V 1 amp". Are most mains powered bells AC?

Most mechanical bells, that are designed for connection to a transformer,
rather than batteries that I have seen, are AC - Isn't there an AC symbol on
the bell
~ is AC
a line with a dashed line is DC - like a =, but one of the lines being
dashed)


Sparks...

Alex wrote:
Adrian C wrote:

You want a bell that rinnnnnnnnnnnnnngs continously when the supply is
connected. Take that ding-dong bell back....


No, it IS that kind of bell that I bought, but it doesn't work that way
when connected to (I think) DC. It's far too quiet to be a "chime" kind.

This is the bell I bought:
http://www.diytools.co.uk/diy/Main/p...ProductID=3782


--
Alex Meaden
Technical Support Officer
Computing Service
remove "+nospam" from address to email

Alex wrote:

This is the bell I bought:
http://www.diytools.co.uk/diy/Main/p...ProductID=3782

Yes, that's an AC bell (clue: "...can only be operated using a
transformer.")


--
Grunff

Alex has brought this to us :
My grandmother's door bell stopped working (one that's mains powered, via a
"hard of hearing" box which also makes a series of lights flash in her
house), so I bought a new "mains powered" 8V bell from B&Q. It doesn't work
properly though; it rings once when you press the button in, and once again
when you release it. I'm guessing the bell wants AC but is getting DC. It
doesn't say on the packaging or the instructions whether it wants AC - only
"8V 1 amp". Are most mains powered bells AC?

The old one was designed to be battery powered by two 1.5V "D" batteries and
the electrician who fitted the "hard of hearing" box and flashy lights just
replaced the batteries with a cable from there, so I guess it could have been
more than 3V and it burned out after a few years. Sadly I can't find my
multimeter to see what it's actually outputting.

alex.

What you have there is what is known as a 'chime', if it makes a ding
-dong noise. That is the way it is designed to work, a ding when
pressed, a dong when released.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org

Alex wrote:
No, it IS that kind of bell that I bought, but it doesn't work that way
when connected to (I think) DC. It's far too quiet to be a "chime" kind.

It's a 50Hz synchronous (AC) bell mechanism then. OK, hands up. I
misunderstood from the post. Your system is, as you rightly guessed, is
feeding out DC - so the armature goes ding on one bell and rebounds ding
on the other (or same bell) when disconnected. Which is also a
description of the intermittant ding-dong chime type. Grrrrr....

Sorry, come back and work as a TSO in my office. I'll get me coat/P45...

:-)
--
Adrian C

Alex explained on 03/08/2005 :
Alex wrote:
Adrian C wrote:

You want a bell that rinnnnnnnnnnnnnngs continously when the supply is
connected. Take that ding-dong bell back....


No, it IS that kind of bell that I bought, but it doesn't work that way
when connected to (I think) DC. It's far too quiet to be a "chime" kind.

This is the bell I bought:
http://www.diytools.co.uk/diy/Main/p...ProductID=3782

That is certainly a bell. You might find that it simply needs to be
adjusted. The dome will be ecentric on the centre screw - if you loosen
the screw a little and turn the dome cover, you should be able to find
a position which works. Then tighten the screw.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org

Grunff explained on 03/08/2005 :
Alex wrote:

This is the bell I bought:
http://www.diytools.co.uk/diy/Main/p...ProductID=3782

Yes, that's an AC bell (clue: "...can only be operated using a transformer.")

It will work perfectly on AC or DC, the problem is that it would need a
rather large battery and expensive battery.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org

On Wed, 03 Aug 2005 18:24:44 +0100,it is alleged that "Harry
Bloomfield" spake thusly in
uk.d-i-y:

Grunff explained on 03/08/2005 :
Alex wrote:

This is the bell I bought:
http://www.diytools.co.uk/diy/Main/p...ProductID=3782

Yes, that's an AC bell (clue: "...can only be operated using a transformer.")

It will work perfectly on AC or DC, the problem is that it would need a
rather large battery and expensive battery.

I have seen 2 different designs of these, one is the standard 'break
the contacts as soon as the armature moves, rinse and repeat' trembler
bell action which IS ac or dc compatible, and one uses a magnetised
core (generally much smaller in size than the trembler one) to operate
in sync with the 50Hz AC mains. If this is one of the latter, or one
of the former in a badly adjusted state, it would give the symptoms
described.


--
There are three things which I consider excellent advice. First, don't
smoke to excess. Second, don't drink to excess.
Third, don't marry to excess.
- Mark Twain

Harry Bloomfield wrote:

It will work perfectly on AC or DC, the problem is that it would need a
rather large battery and expensive battery.


I've seen some beels (this isn't a chime, it's a ringing bell) which
don't have contacts, and rely on the AC to grab/release the striker -
from the OP's description, I'm assuming that this is such a bell.


--
Grunff

Grunff wrote:
Alex wrote:

This is the bell I bought:
http://www.diytools.co.uk/diy/Main/p...ProductID=3782


Yes, that's an AC bell (clue: "...can only be operated using a
transformer.")



Nope, these type typically have a solenoid, the plunger of which strikes
the bell housing, but on its travel it actuates a normally-closed
contact, thus releasing the supply to the solendoid. Having "dung" the
bell, the spring contact of the nc-contact (or an ancillary spring)
returns the plunger to the neutral (energised position) ready for the
cycle to be repeated.

Basically - runs off AC or DC, doesn't really matter.

To the OP - these tend to have a meaty solenoid so just make sure the
supply is sufficiently rated.

In article ,
Alex wrote:
It doesn't work properly though; it rings once when you press the button
in, and once again when you release it.


Can you not stick a sign up asking people to press it repeatedly? Around
50 times a second would probably be best

HTH,

Darren

Alex wrote:
My grandmother's door bell stopped working (one that's mains powered,
via a "hard of hearing" box which also makes a series of lights flash in
her house), so I bought a new "mains powered" 8V bell from B&Q. It
doesn't work properly though; it rings once when you press the button
in, and once again when you release it. I'm guessing the bell wants AC
but is getting DC. It doesn't say on the packaging or the instructions
whether it wants AC - only "8V 1 amp". Are most mains powered bells AC?

The "8V 1 amp" is the giveaway - batteries with such voltage don't
exist as far as your concerned. Hence, it's after AC.

As others have mentioned some AC bells will work from DC but given
you're having problems I wouldn't make that assumption for yours.