Hi Folks,
My nephew bought the keypad access control "kit" from Screwfix - their
part number 27496-77 (page 169 of the most recent catalogue).
The locking "strike" seems standard, the keypad takes 12 to 15volts DC
and
looks "standard", the transformer is one of those with screwholes and
a DIN-mounting capability.

Since nephew had some "issues" with wiring the whole lot together, I
got
a phone call. Eventually I cut my losses and said "just bring it to me
and
I'll temporarily wire it up then you can take it home and install it
proper."

The transformer in the picture (the white cube on the left in the
catalogue) is
basically just that, with an AC output.
Being in the fortunate position to own an oscilloscope, I even
double-checked
what I saw and watched quite a nice sine wave appear.

When you read all the blurb about the keypad, it states that it needs
DC.

So I emailled Screwfix and asked their advice.

The reply I got was:
We have supplied many of these items in the past and have not
had any queries of this nature.

I would suggest that you contact our supplier, Tate Fire on 01934
744111,
and discuss it with them. They are in a much better position to
advise you
as to compatibility than we are.

I don't want to send 12 volts AC into a unit that takes 12v DC.

I'm thinking that some electrically-ignorant bod has seen that the
solenoid
lock mechanism can take AC or DC so they have presumed that the
electronics
can do so too.
I haven't looked in depth at the keypad electronics - I suppose I
could
look for a bridge rectifier on the power side, but I'm guessing there
won't
be one of these.

So, has anyone else here bought such a unit, and if so how did you get
on
with it?

I could lash together a rectifier, smoothing capacitor and voltage
regulator
to give sufficient DC, but having paid ninety quid for the pleasure I
think
my nephew ought to deserve better.

Feedback requested please; thanks in advance.

Mungo

In article ,
Mungo Henning wrote:
I don't want to send 12 volts AC into a unit that takes 12v DC.

If you do it'll be toast. ;-)

--
*Re-elect nobody

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Mungo Henning wrote:
The transformer in the picture (the white cube on the left in the
catalogue) is basically just that, with an AC output. Being in the
fortunate position to own an oscilloscope, I even double-checked what I
saw and watched quite a nice sine wave appear.

I'd expect it to be marked with the output.

When you read all the blurb about the keypad, it states that it needs DC.

Thinking on it, the solenoid will take the majority of the current, so
that might just be AC driven, while the keypad electronics have their own
internal rectifier, etc. This would allow a smaller sized enclosure for
the power supply - and indeed perhaps only transformers rather than power
supplies are available in this DIN fitting type.

--
*Prepositions are not words to end sentences with *

Dave Plowman London SW
To e-mail, change noise into sound.

In message , Mungo
Henning wrote
Hi Folks,
My nephew bought the keypad access control "kit" from Screwfix - their
part number 27496-77 (page 169 of the most recent catalogue).
The locking "strike" seems standard, the keypad takes 12 to 15volts DC
and
looks "standard", the transformer is one of those with screwholes and
a DIN-mounting capability.

Since nephew had some "issues" with wiring the whole lot together, I
got
a phone call. Eventually I cut my losses and said "just bring it to me
and
I'll temporarily wire it up then you can take it home and install it
proper."

The transformer in the picture (the white cube on the left in the
catalogue) is
basically just that, with an AC output.
Being in the fortunate position to own an oscilloscope, I even
double-checked
what I saw and watched quite a nice sine wave appear.

When you read all the blurb about the keypad, it states that it needs
DC.

http://www.tateuk.com/

The data sheets or the specs on the Tate site indicate that the keypads
are 10 to 15V dc or 12V ac. They may have a bridge rectifier as the
first active component after the input thus allowing both ac and dc.

The transformer shown in Screwfix appears to be the same as the ones
shown on the Tate Fire site.

--
Alan

Alan wrote in message ...


http://www.tateuk.com/

The data sheets or the specs on the Tate site indicate that the keypads
are 10 to 15V dc or 12V ac. They may have a bridge rectifier as the
first active component after the input thus allowing both ac and dc.

The transformer shown in Screwfix appears to be the same as the ones
shown on the Tate Fire site.


My sister phoned Tate earlier today and was told that the keypad could
tolerate an AC supply. They just haven't got round to updating the
instructions... !

Thanks to all who responded.

Mungo

.... if all else fails, read the instructions... :-)