W
Watson A.Name - \"Watt Su
Guest
I replaced my smoke detector, since the old one was dated April, 1984.
The new one says that it should be replace in ten years, and has the
date of manuffacture. The old one said no such thing. There has been
discussions here in the past about smoke detectors, and I had thought
that the half life of the Americium was leess, so that after a dozen
years it would become weak, but that's not true, it has a half life of
over 400 years.
So I got on and googled for americium smoke detectors and found out a
lot about them, mainly that the americium was located in the ionization
chamber. The old one looks much like the one at this URL.
http://www.theodoregray.com/PeriodicTable/Elements/095/index.s7.html
I took the lid off the ionization chamber, but put it back on when I
found that it was still spewing alpha particles and gamma rays.
I was thinking about removing the ionization chamber, but from what I've
read, the ionization keeps it turned off, so removing the inoization
source would cause it to go to constant alarm state. The circuit board
has only a single chip, with just a bunch of resistors, a couple caps
and a rectifier. THe chip as a house number on it, so it's probably a
special chip. Pin 3 has been flipped up to contact the chamber, and
some insulating goop has been put around it. A lot of the resistors are
multi megohms. I'm not sure what would be needed to simulate the
ionization chamber.
I was thinking that I might be able to use the piezoelectric tweeter to
make a very loud alarm, for intrusion detection. The old smoke detector
was made by First Alert, not much help. I googled for smoke detector
schematics and came up with only one on Discover Circuits and it was the
photon detector using a PIN diode. Maybe I could put a 10meg resistor
across the chamber contacts to simulate it. Has anyone done this?
I wasnted to read the story about the kid who built his own reactor, but
when I clicked on the link, the URL gave an error, so I googled for
"Nuke Kid On The Block" and the story came up.
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
The new one says that it should be replace in ten years, and has the
date of manuffacture. The old one said no such thing. There has been
discussions here in the past about smoke detectors, and I had thought
that the half life of the Americium was leess, so that after a dozen
years it would become weak, but that's not true, it has a half life of
over 400 years.
So I got on and googled for americium smoke detectors and found out a
lot about them, mainly that the americium was located in the ionization
chamber. The old one looks much like the one at this URL.
http://www.theodoregray.com/PeriodicTable/Elements/095/index.s7.html
I took the lid off the ionization chamber, but put it back on when I
found that it was still spewing alpha particles and gamma rays.
I was thinking about removing the ionization chamber, but from what I've
read, the ionization keeps it turned off, so removing the inoization
source would cause it to go to constant alarm state. The circuit board
has only a single chip, with just a bunch of resistors, a couple caps
and a rectifier. THe chip as a house number on it, so it's probably a
special chip. Pin 3 has been flipped up to contact the chamber, and
some insulating goop has been put around it. A lot of the resistors are
multi megohms. I'm not sure what would be needed to simulate the
ionization chamber.
I was thinking that I might be able to use the piezoelectric tweeter to
make a very loud alarm, for intrusion detection. The old smoke detector
was made by First Alert, not much help. I googled for smoke detector
schematics and came up with only one on Discover Circuits and it was the
photon detector using a PIN diode. Maybe I could put a 10meg resistor
across the chamber contacts to simulate it. Has anyone done this?
I wasnted to read the story about the kid who built his own reactor, but
when I clicked on the link, the URL gave an error, so I googled for
"Nuke Kid On The Block" and the story came up.
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
