UK source for this magnetic switch?

[Terry Pinnell]

Can anyone point me towards a UK source (phone or online) for an
inexpensive cylindrical, enclosed reed switch, N/C, for use in a
burglar alarm circuit please.

I'm still googling but so far without success and want to place an
order for delivery Monday.

--
Terry, East Grinstead, UK

 

[William Sommerwerck]

Aren't there any electronic-parts distributors in the UK that consumers can
purchase from?

 

[Adrian C]

William Sommerwerck wrote:

Aren't there any electronic-parts distributors in the UK that consumers can
purchase from?

"electronic-parts distributor" in the UK implies a trade only source
with limited interest in selling to retail customers. Those that do,
typically charge exorbitant delivery, minimun order and service charges
- leaving the only real alternative to be a toy shop called Maplin. Or eBay.

--
Adrian C

 

[IanM]

Terry wrote:
Can anyone point me towards a UK source (phone or online) for an
inexpensive cylindrical, enclosed reed switch, N/C, for use in a
burglar alarm circuit please.

William Sommerwerck wrote:

Aren't there any electronic-parts distributors in the UK that consumers can
purchase from?


Plenty, but he's looking for the wrong thing.

There is no such thing as a NC reed switch. The induced magnetism in the
reeds *always* attracts them together when you bring the magnet up, and
never repels them so all two terminal bare reed switches are NO.
It is possible to put an additional non-magnetic reed in the capsule, so
that one of the magnetic reeds is in contact with it until an external
magnetic field is applied, but as the reeds have to be brought out
through the pinch of the glass capsule to support them, this provides a
SPDT switch, not a NC one although it can be used as such.

If he googles 'SPDT reed switch' (without the quotes), both Rapid and
Maplin stock them. but for alarm use, I'm fairly sure he wants a
complete reed sensor and magnet pair for a NC loop, NOT a bare reed capsule.

If he's looking for a switch/magnet pair he can mount in the edge of a
door and its frame in drilled holes, googling 'recessed reed switch'
will find plenty, all NC in the presence of their magnet (i.e. with the
door closed). Again Maplin have some.

If he wants a true NC action, he's either going to have to stick a bare
SPDT reed in a cylindrical housing e.g a plastic tube from a biro with a
dab of hot glue or mess around with a biasing magnet to cancel out the
field of the actuating magnet as it approaches. Enclosed SPDT reed
switches, although nearly as rare as hens teeth, are available but
apparently not in a cylindrical recessed format.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL:

 

[PeterD]

On Sat, 07 Feb 2009 11:32:23 +0000, Terry Pinnell
<terrypinDELETE@THESEdial.pipex.com> wrote:

Can anyone point me towards a UK source (phone or online) for an
inexpensive cylindrical, enclosed reed switch, N/C, for use in a
burglar alarm circuit please.

I'm still googling but so far without success and want to place an
order for delivery Monday.

No Radio Shack there? Try an alarm company then... They were commonly
used in the big dish satellite systems on the positioning motor, but
since big dishes are uncommon now, that's not a good source, but some
satellite dish companies may have a few sitting on the shelf.

 

[christofire]

"Adrian C" <email@here.invalid> wrote in message
news:6v5gdpFh7meoU1@mid.individual.net...

William Sommerwerck wrote:
Aren't there any electronic-parts distributors in the UK that consumers
can
purchase from?

"electronic-parts distributor" in the UK implies a trade only source with
limited interest in selling to retail customers. Those that do, typically
charge exorbitant delivery, minimun order and service charges - leaving
the only real alternative to be a toy shop called Maplin. Or eBay.

--
Adrian C

Who could forget CPC/Farnell? Deal with them once and they'll keep your
letter box well fed for the rest of your life!

Excellent stock range though, miles bigger than Maplin.

Chris

 

[Phil Allison]

"Ian Massive Pedant "
Terry wrote:

Can anyone point me towards a UK source (phone or online) for an
inexpensive cylindrical, enclosed reed switch, N/C, for use in a
burglar alarm circuit please.


There is no such thing as a NC reed switch.

** It's a better than even money bet Terry wants the switch to be closed
with a magnet nearby.

Which IS the NORMAL situation in an alarm installation.



...... Phil

 

[Adrian C]

christofire wrote:

Who could forget CPC/Farnell? Deal with them once and they'll keep your
letter box well fed for the rest of your life!

Yeah, but they are trade.

You can deal as an individual but on small quantities you pay postage,
don't get free technical support etc.. Basically 2nd class treatment and
they make you feel that. Attempts at getting trade registration for my
credit worthy limited company failed at Farnell without an explanation
why :-(

It takes a bit longer, but I find eBay works for me. If it's urgent,
then Maplin, Cricklewood Electronics or me turning up at an RS trade
counter with my VAT registration certificate (yes really).

BTW Radio Shack pulled out years ago. Now that was a toy shop...

--
Adrian C

 

[IanM]

Phil Allison wrote:

"Ian Massive Pedant "
Terry wrote:
Can anyone point me towards a UK source (phone or online) for an
inexpensive cylindrical, enclosed reed switch, N/C, for use in a
burglar alarm circuit please.

There is no such thing as a NC reed switch.


** It's a better than even money bet Terry wants the switch to be closed
with a magnet nearby.

Which IS the NORMAL situation in an alarm installation.



..... Phil

You snipped the bit where I gave a usable search term and suggestion for
a retail supplier for exactly that! Here, I've put it back:

for alarm use, I'm fairly sure he wants a complete reed sensor and
magnet pair for a NC loop, NOT a bare reed capsule.

If he's looking for a switch/magnet pair he can mount in the edge
of a door and its frame in drilled holes, googling 'recessed reed
switch' will find plenty, all NC in the presence of their magnet
(i.e. with the door closed). Again Maplin have some.

Thanks for not swearing ;-)

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL:

 

[Dave Plowman (News)]

In article <gmju8t$2qn$1@news.motzarella.org>,
William Sommerwerck <grizzledgeezer@comcast.net> wrote:

Aren't there any electronic-parts distributors in the UK that consumers
can purchase from?

You don't even need an electronics distributor - electrical wholesalers
keep this sort of thing.

http://www.tlc-direct.co.uk/Main_Index/Alarm_Index/Alarm_Accessories/index.html

and will sell any value item with no surcharge in their branches. I've
never used them for mail order.

Most electronics distributors will have a minimum order - or high P&P for
a small value item.

Maplin (UK sort of RS) *may* have this sort of thing in some shops.

Or of course Ebay.

--
*Taxation WITH representation ain't much fun, either.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[christofire]

"Adrian C" <email@here.invalid> wrote in message
news:6v5jhmFicegvU1@mid.individual.net...

christofire wrote:

Who could forget CPC/Farnell? Deal with them once and they'll keep your
letter box well fed for the rest of your life!

Yeah, but they are trade.

You can deal as an individual but on small quantities you pay postage,
don't get free technical support etc.. Basically 2nd class treatment and
they make you feel that. Attempts at getting trade registration for my
credit worthy limited company failed at Farnell without an explanation why
:-(

I've never had a problem with CPC that wasn't resolved with an e-mail or
two. According to http://cpc.farnell.com/terms-and-conditions it's 'Small
Order Handling Charges', not postage, that they levy on orders smaller than
Ł45 ex VAT. I guess this amounts to the same, but I don't think I've ever
needed to trouble them with less than 45 quids' worth.

Chris

 

[Jasen Betts]

On 2009-02-07, Adrian C <email@here.invalid> wrote:

William Sommerwerck wrote:
Aren't there any electronic-parts distributors in the UK that consumers can
purchase from?

"electronic-parts distributor" in the UK implies a trade only source
with limited interest in selling to retail customers. Those that do,
typically charge exorbitant delivery, minimun order and service charges
- leaving the only real alternative to be a toy shop called Maplin. Or eBay.

Find one where you can walk in off the street during business hours
if you demonstrate posession of atleast half a clue when you walk in
and pay cash they'll treat you ok.

 

[Dave Plowman (News)]

In article <gmm8ih$m9$1@reversiblemaps.ath.cx>,
Jasen Betts <jasen@xnet.co.nz> wrote:

"electronic-parts distributor" in the UK implies a trade only source
with limited interest in selling to retail customers. Those that do,
typically charge exorbitant delivery, minimun order and service
charges - leaving the only real alternative to be a toy shop called
Maplin. Or eBay.

Find one where you can walk in off the street during business hours
if you demonstrate posession of atleast half a clue when you walk in
and pay cash they'll treat you ok.

The only one in the UK which has trade counters in several cities is RS
Components - and they won't serve someone walking in off the street. And
rightly so - a genuine client shouldn't have to wait while an amateur asks
for advice, etc.

Maplin is the place for that sort of thing.

--
*I can see your point, but I still think you're full of shit.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Baron]

Dave Plowman (News) wrote:

In article <gmm8ih$m9$1@reversiblemaps.ath.cx>,
Jasen Betts <jasen@xnet.co.nz> wrote:
"electronic-parts distributor" in the UK implies a trade only
source with limited interest in selling to retail customers. Those
that do, typically charge exorbitant delivery, minimun order and
service charges - leaving the only real alternative to be a toy
shop called Maplin. Or eBay.

Find one where you can walk in off the street during business hours
if you demonstrate posession of atleast half a clue when you walk in
and pay cash they'll treat you ok.

The only one in the UK which has trade counters in several cities is
RS Components - and they won't serve someone walking in off the
street. And rightly so - a genuine client shouldn't have to wait while
an amateur asks for advice, etc.

Maplin is the place for that sort of thing.

Actally B&Q, Focus, Wikkes, Aldi, Morrisons, Even Asda have or have had
similar devices on their shelves !

--
Best Regards:
Baron.

 

[Baron]

Dave Plowman (News) wrote:

In article <gmmemm$a84$1@news.motzarella.org>,
Baron <baron.nospam@linuxmaniac.nospam.net> wrote:
Dave Plowman (News) wrote:

In article <gmm8ih$m9$1@reversiblemaps.ath.cx>,
Jasen Betts <jasen@xnet.co.nz> wrote:
"electronic-parts distributor" in the UK implies a trade only
source with limited interest in selling to retail customers.
Those that do, typically charge exorbitant delivery, minimun
order and service charges - leaving the only real alternative to
be a toy shop called Maplin. Or eBay.

Find one where you can walk in off the street during business
hours if you demonstrate posession of atleast half a clue when you
walk in and pay cash they'll treat you ok.

The only one in the UK which has trade counters in several cities
is RS Components - and they won't serve someone walking in off the
street. And rightly so - a genuine client shouldn't have to wait
while an amateur asks for advice, etc.

Maplin is the place for that sort of thing.


Actally B&Q, Focus, Wikkes, Aldi, Morrisons, Even Asda have or have
had similar devices on their shelves !

But not a N/C one. You'll need to obtain the correct reed switch
elsewhere and fit it to the housing. Or just use a transistor to
invert the output as I suggested earlier.

All the ones I referred to were standard reeds with an actuating magnet
in a separate housing. Ak for burglar alarm systems.
I've never seen a normally closed one used for those, although I have
seen change over, SPCO, reeds used in electronic equipment.

--
Best Regards:
Baron.

 

[Dave Plowman (News)]

In article <gmmemm$a84$1@news.motzarella.org>,
Baron <baron.nospam@linuxmaniac.nospam.net> wrote:

Dave Plowman (News) wrote:

In article <gmm8ih$m9$1@reversiblemaps.ath.cx>,
Jasen Betts <jasen@xnet.co.nz> wrote:
"electronic-parts distributor" in the UK implies a trade only
source with limited interest in selling to retail customers. Those
that do, typically charge exorbitant delivery, minimun order and
service charges - leaving the only real alternative to be a toy
shop called Maplin. Or eBay.

Find one where you can walk in off the street during business hours
if you demonstrate posession of atleast half a clue when you walk in
and pay cash they'll treat you ok.

The only one in the UK which has trade counters in several cities is
RS Components - and they won't serve someone walking in off the
street. And rightly so - a genuine client shouldn't have to wait while
an amateur asks for advice, etc.

Maplin is the place for that sort of thing.


Actally B&Q, Focus, Wikkes, Aldi, Morrisons, Even Asda have or have had
similar devices on their shelves !

But not a N/C one. You'll need to obtain the correct reed switch elsewhere
and fit it to the housing. Or just use a transistor to invert the output
as I suggested earlier.

--
*When cheese gets it's picture taken, what does it say?

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Terminal Crazy]

In article <502a5552c0dave@davenoise.co.uk>, Dave Plowman (News)
<dave@davenoise.co.uk> wrote:

The only one in the UK which has trade counters in several cities is RS
Components - and they won't serve someone walking in off the street. And
rightly so - a genuine client shouldn't have to wait while an amateur
asks for advice, etc.

CPC have counters and served me, but i have registered an account on their
web site . It was No problem and the parts were waiting for pick up.

--
Terminal_Crazy

Mitch - 1995 Z28 LT1 M6 terminal_crazy@sand-hill.freeserve.co.uk
Lancashire England http://www.sand-hill.freeserve.co.uk/terminal_crazy/

 

[Ron]

Terminal Crazy wrote:

In article <502a5552c0dave@davenoise.co.uk>, Dave Plowman (News)
dave@davenoise.co.uk> wrote:
The only one in the UK which has trade counters in several cities is RS
Components - and they won't serve someone walking in off the street. And
rightly so - a genuine client shouldn't have to wait while an amateur
asks for advice, etc.

CPC have counters and served me, but i have registered an account on their
web site . It was No problem and the parts were waiting for pick up.

I buy from CPC weekly, my orders generally are for more than the minumum

carriage free amount, Ł45 IIRC, but I think it`s only a few pounds for
standard delivery.

As far as CPC being trade only. that`s a laugh, it was a big bone of
contention a few years ago when they started putting their weekly
special offer leaflets in punter magazines and opened a 'trade counter'
that is open to all. I`ve dealt with CPC since the early 80`s, they are
a good company, I`ve had very few problems, and complains are dealt with
asap.

Farnell also will hapily sell to the public via their website - The
Farnell organisation own CPC btw, I`ve also had good dealings with Rapid
Online.


Ron

 

[Adrian C]

Ron wrote:

Farnell also will hapily sell to the public via their website - The
Farnell organisation own CPC btw, I`ve also had good dealings with Rapid
Online.

Happily, that's a laugh.. :-(

The word is grudgingly. Both CPC and Farnell technical support is free
for account holders, and there is no minimum order for trade customers.
Other companies even have free post for trade customers on any order
size. Because on things like internet sales they have to agree to
"distance selling regulations" and similar, they end up losing money
dealing with consumers. Maplin is the only UK national choice for
hobbyists and small time repairers like me.

Never mind, if it works for you. Good

eBay and purchasing outside the UK works for me and yes; I know what a
scam fest eBay can sometimes be, but not in this case.

For example I recently had to replace a shot schottky SMD diode in a HP
printer SMPS. Per part, 20p each from Farnell. Minimun order charge Ł20.
Post and packing Ł4.25.

From an eBay seller in the states, Ł8 including postage for 500 diodes.
They were delivered within the week.

If it's urgent I jump in the car and find something in a shop closer. Or
risk a dodgy substitute for the part, which I really shouldn't do if
it's critical ....

--
Adrian C

 

[Dave Plowman (News)]

In article <502a658ca9Terminal_Crazy@sand-hill.freeserve.co.uk>,
Terminal Crazy <Terminal_Crazy@sand-hill.freeserve.co.uk> wrote:

In article <502a5552c0dave@davenoise.co.uk>, Dave Plowman (News)
dave@davenoise.co.uk> wrote:
The only one in the UK which has trade counters in several cities is
RS Components - and they won't serve someone walking in off the
street. And rightly so - a genuine client shouldn't have to wait while
an amateur asks for advice, etc.

CPC have counters and served me, but i have registered an account on
their web site . It was No problem and the parts were waiting for pick
up.

I understood CPC have only the one trade counter - unlike RS Components
who have some 15 in various parts of the country.

--
*Atheism is a non-prophet organization.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.