Is there a device I can use or mutate such that if my front door is left
open for more than a minute an alarm will sound -
(people leave it looking shut but with a gap so loads of warm air is lost.)
((My front door is very heavy so I'm not sure a door closer would work
in wind))
[g]

george [dicegeorge] wrote:

Is there a device I can use or mutate such that if my front door is left
open for more than a minute an alarm will sound -
(people leave it looking shut but with a gap so loads of warm air is
lost.) ((My front door is very heavy so I'm not sure a door closer would
work in wind))
[g]

A reed switch and a magnet would form the basis of the detection mechanism -
especially as you can get made-for-purpose magnets and reeds.

Buzzers and 9V batteries are easy.

So that just leaves the problem of a time delay. I would use a 555 timer
chip on a bit of veroboard, but if that scares you - I'm not sure what to
suggest - maybe someone else can think of something?

--
Tim Watts

On Sat, 12 Nov 2011 12:36:55 +0000, "george [dicegeorge]"
wrote:

Is there a device I can use or mutate such that if my front door is left
open for more than a minute an alarm will sound -
(people leave it looking shut but with a gap so loads of warm air is lost.)
((My front door is very heavy so I'm not sure a door closer would work
in wind))
[g]

You want a fridge alarm - or similar. Try
http://fridge-freezer-alarm.co.uk/

But I've never used them.

On 12/11/2011 15:06, Simon Cee wrote:
On Sat, 12 Nov 2011 12:36:55 +0000, "george [dicegeorge]"
wrote:

Is there a device I can use or mutate such that if my front door is left
open for more than a minute an alarm will sound -
(people leave it looking shut but with a gap so loads of warm air is lost.)
((My front door is very heavy so I'm not sure a door closer would work
in wind))
[g]

You want a fridge alarm - or similar. Try
http://fridge-freezer-alarm.co.uk/

But I've never used them.

This came up a few weeks ago. I have the one with the variable delay and
it would do the job perfectly, but it's a bit bulky and wouldn't look
very nice on a front door

--
Reentrant

On 12/11/2011 13:41, Tim Watts wrote:
george [dicegeorge] wrote:

Is there a device I can use or mutate such that if my front door is left
open for more than a minute an alarm will sound -
(people leave it looking shut but with a gap so loads of warm air is
lost.) ((My front door is very heavy so I'm not sure a door closer would
work in wind))
[g]

A reed switch and a magnet would form the basis of the detection mechanism -
especially as you can get made-for-purpose magnets and reeds.

Buzzers and 9V batteries are easy.

So that just leaves the problem of a time delay. I would use a 555 timer
chip on a bit of veroboard, but if that scares you - I'm not sure what to
suggest - maybe someone else can think of something?

A wall-wart power supply, and a "time-delay on" relay would do the trick
to complete your circuit if the OP doesn't want to get down to component
level.

SteveW

On 12 Nov,
"george [dicegeorge]" wrote:

Is there a device I can use or mutate such that if my front door is left
open for more than a minute an alarm will sound -
(people leave it looking shut but with a gap so loads of warm air is lost.)
((My front door is very heavy so I'm not sure a door closer would work
in wind))
[g]

Thermostat feeding electric bell (and wires to croc clips to apply to
miscreants.....)


--
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