angelcare baby monitor sensor pad

  • Thread starter bluemountains George
  • Start date
B

bluemountains George

Guest
Just wondering if anyone with a newborn who has those Angelcare baby
monitors with sensor pad.

Has anyone opened up motion sensor pad? My wife wont let me and I am
dying to know how it works. There are only 2 wires and I cant
imagine its too hitech but it seems to detect baby breathing movements
through a thick mattress???

http://www.angelcare-uk.co.uk/content/201.pdf
 
On 08-Mar-10 13:59, bluemountains George wrote:
Just wondering if anyone with a newborn who has those Angelcare baby
monitors with sensor pad.

Has anyone opened up motion sensor pad? My wife wont let me and I am
dying to know how it works. There are only 2 wires and I cant
imagine its too hitech but it seems to detect baby breathing movements
through a thick mattress???

http://www.angelcare-uk.co.uk/content/201.pdf
Click to expand...
Never seen one, is it firm to the touch or spongy?

If the former, my guess would be pressure/resistive, if the latter then
possibly an air bladder with passive pressure sensor? Which is cheaper?
Have to watch out for punctures if it's a bladder...

--
Chris.
 
Its springy. The slightest tap it measures about .4 to over 2v AC for
a sharp tap. Not sensitive to sound, just heavy vibration. I thought
piezo but in that case wouldnt need a moving spongy plate which what
this is.
Its designed to set off an alarm if baby doesnt move (breathe) in a 15
sec period.
 
On 2010-03-08, bluemountains George <socrates_01@hotmail.com> wrote:
Its springy. The slightest tap it measures about .4 to over 2v AC for
a sharp tap. Not sensitive to sound, just heavy vibration. I thought
piezo but in that case wouldnt need a moving spongy plate which what
this is.
Its designed to set off an alarm if baby doesnt move (breathe) in a 15
sec period.
Click to expand...
piezo's not too good at low freuency. could be a magnetic pickup? is
there any evidence of a permanent magnet - does ant part of it deflect
a compass needle.



--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
 
On 08-Mar-10 15:56, bluemountains George wrote:
Its springy. The slightest tap it measures about .4 to over 2v AC for
a sharp tap. Not sensitive to sound, just heavy vibration. I thought
piezo but in that case wouldnt need a moving spongy plate which what
this is.
Its designed to set off an alarm if baby doesnt move (breathe) in a 15
sec period.
Click to expand...
So it *produces* a voltage without external supply/excitation?
 
On Mar 9, 12:27 pm, cth <a...@b.c> wrote:
On 08-Mar-10 15:56, bluemountains George wrote:

Its springy. The slightest tap it measures about .4 to over 2v AC for
a sharp tap.  Not sensitive to sound, just heavy vibration. I thought
piezo but in that case wouldnt need  a moving spongy plate which what
this is.
Its designed to set off an alarm if baby doesnt move (breathe) in a 15
sec period.

So it *produces* a voltage without external supply/excitation?
Click to expand...

yes correct, without anypower it produces up to 2v acpeaks .
the pad is 2 splitplastic pads connected together on some sort of
flexible gymbal with a few mm of rocking movement.
I cant open the pad without damaging it.
 
On 09-Mar-10 14:04, bluemountains George wrote:
On Mar 9, 12:27 pm, cth<a...@b.c> wrote:
On 08-Mar-10 15:56, bluemountains George wrote:

Its springy. The slightest tap it measures about .4 to over 2v AC for
a sharp tap. Not sensitive to sound, just heavy vibration. I thought
piezo but in that case wouldnt need a moving spongy plate which what
this is.
Its designed to set off an alarm if baby doesnt move (breathe) in a 15
sec period.

So it *produces* a voltage without external supply/excitation?


yes correct, without anypower it produces up to 2v acpeaks .
the pad is 2 splitplastic pads connected together on some sort of
flexible gymbal with a few mm of rocking movement.
I cant open the pad without damaging it.
Click to expand...
I read this as 2 inflexible pads with, my guess, a flexible
piezoelectric film/ribbon (such as
http://www.meas-spec.com/piezo-film-sensors.aspx) between the two. As
long as the movement never entirely stops there'll be some output (which
is what's required!)

--
FWIW,
Chris.
 
cth Inscribed thus:

On 09-Mar-10 14:04, bluemountains George wrote:
On Mar 9, 12:27 pm, cth<a...@b.c> wrote:
On 08-Mar-10 15:56, bluemountains George wrote:

Its springy. The slightest tap it measures about .4 to over 2v AC
for
a sharp tap. Not sensitive to sound, just heavy vibration. I
thought
piezo but in that case wouldnt need a moving spongy plate which
what this is.
Its designed to set off an alarm if baby doesnt move (breathe) in a
15 sec period.

So it *produces* a voltage without external supply/excitation?


yes correct, without anypower it produces up to 2v acpeaks .
the pad is 2 splitplastic pads connected together on some sort of
flexible gymbal with a few mm of rocking movement.
I cant open the pad without damaging it.

I read this as 2 inflexible pads with, my guess, a flexible
piezoelectric film/ribbon (such as
http://www.meas-spec.com/piezo-film-sensors.aspx) between the two. As
long as the movement never entirely stops there'll be some output
(which is what's required!)

--
FWIW,
Chris.
Click to expand...
MIL has a similar device that warns us if she gets out of bed, though I
suspect that its some kind of pressure sensitive device. Its very
similar to an electric under blanket in appearance.

--
Best Regards:
Baron.
 
bluemountains George wrote:
Just wondering if anyone with a newborn who has those Angelcare baby
monitors with sensor pad.

Has anyone opened up motion sensor pad? My wife wont let me and I am
dying to know how it works. There are only 2 wires and I cant
imagine its too hitech but it seems to detect baby breathing movements
through a thick mattress???

http://www.angelcare-uk.co.uk/content/201.pdf
Click to expand...
How about a big dynamic mic, with the spongy pillow part being the
diaphragm. This would generate a voltage proportional to movement.
 
bluemountains George wrote:
On Mar 9, 12:27 pm, cth <a...@b.c> wrote:
On 08-Mar-10 15:56, bluemountains George wrote:

Its springy. The slightest tap it measures about .4 to over 2v AC for
a sharp tap. Not sensitive to sound, just heavy vibration. I thought
piezo but in that case wouldnt need a moving spongy plate which what
this is.
Its designed to set off an alarm if baby doesnt move (breathe) in a 15
sec period.
So it *produces* a voltage without external supply/excitation?


yes correct, without anypower it produces up to 2v acpeaks .
the pad is 2 splitplastic pads connected together on some sort of
flexible gymbal with a few mm of rocking movement.
I cant open the pad without damaging it.
Click to expand...
Someone is going to use one of these as a kick drum microphone one day.
 
"bluemountains George" <socrates_01@hotmail.com> wrote in message
news:9491aa95-79aa-40dc-95ab-7a5d03ece3d8@c34g2000pri.googlegroups.com...
Just wondering if anyone with a newborn who has those Angelcare baby
monitors with sensor pad.

Has anyone opened up motion sensor pad? My wife wont let me and I am
dying to know how it works. There are only 2 wires and I cant
imagine its too hitech but it seems to detect baby breathing movements
through a thick mattress???

http://www.angelcare-uk.co.uk/content/201.pdf
Click to expand...


maybe its among this stuff:

http://www.patentgenius.com/assignee/GracoChildrensProductsInc.html
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top