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Subject: RE: [FlyRotary] Re: Fire Detector Unit
Date: Mon, 27 Feb 2006 08:46:30 -0600
Message-ID: <87DBA06C9A5CB84B80439BA09D86E69E03D05830@MAIL01.austin.utexas.edu>
Thread-Topic: [FlyRotary] Re: Fire Detector Unit
Thread-Index: AcY6A9RbKjtPaB8LS0iIpLAM16gkvQBoV5Lg
From: "Mark R Steitle" <mark.steitle@austin.utexas.edu>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>

If Acroname.com has the inventory on hand (no reason to think
otherwise), it looks to be a good source for the UVTRON fire detectors
and circuit boards.  The question is can it run a good sized LED without
needing a relay board.  Output is 50v, so that would have to be dealt
with (following Ed's recommendations).  So, it appears that a relay
board won't be necessary unless you're planning on using a landing light
as a warning indicator.  The C3704 is rated for 10 - 30 volts input, so
that eliminates the need for the voltage converter board.  They have two
other models if you need a different input voltage.  The board would
need to be mounted in a project box (readily available at Frye's) with a
window cut for the UVTRON to look through.  I used nylon screws from the
Home Depot avionics department to mount the board.=20

From the picture on the Acroname web site, it doesn't appear that the
board is protective coated.  IMHO, this should be done to improve
longevity and reliability.  The coating should be available from a
number of electronics suppliers, or use something like epoxy resin or
E6000. =20

One other caution, the UVtron operates at 350v, so be careful handling
it while it is powered up.

All in all, it appears the single-board solution would be a more elegant
solution, but would require some experimenting to get it to do what we
want.  We know that the 3-board solution works as is.  So, its up to
each to determine which option suits your needs.

Since Bob Darrah had indicated he was interested in this item, he's
agreed to order one of the boards and we will test it out to see if it
will power an LED, and what additional components it needs to make that
happen.  I will report back to the group with the good, the bad and the
ugly. =20

Mark
   =20

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Chad Robinson
Sent: Saturday, February 25, 2006 6:05 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Fire Detector Unit

Tracy Hallock wrote:
>=20
> After seeing Mark's demonstration, I was pretty impressed, so I did a=20
> search on the internet for similar products.  The link below looked=20
> promising:
> =20
> http://www.georgejenson.com/rv7.php
> =20
> They include a board and the detector for $72.  Unfortunately, I am
too=20
> far off from needing this yet, but someone else might like to
experiment.

Tracy, did you mean to include this link as opposed to the one above?
http://www.acroname.com/robotics/parts/R67-UVTRON.html

This is a good way to go if you're serious about using this detector. It
runs=20
on 10-30VDC, and you can get a project box from Radio Shack for a few
bucks=20
that will fit it.

Note that if you want to use this, you will need some way to indicate
its=20
output. A good way would be a 12V relay, light, and buzzer, also from
Radio=20
Shack. You'd hook the relay to "output pin 3 - Open Collector Output",
and use=20
it to drive the indicator light (or LED) and the buzzer. Make sure the
coil=20
rating of the relay you get doesn't exceed 100mA at 12V (coil resistance
120=20
ohms max).

Finally, the output of this thing is a very short pulse. The spec sheet
for=20
the driver circuit says you can add a capacitor at a spot on the circuit

board. Again, Radio Shack sells capacitors. A 1uF value across the Cx=20
terminals will make the output pulse for 1 second at a time. Don't
forget to=20
jumper the "background cancel level" terminals, too. Looks like you'd
want to=20
use position 3 - they label this "general use". You can experiment with
a=20
different slot if it's falsely triggering.

Sounds like a lot of hookup work, but you could probably do it (minus
wiring=20
and installing it) in 20 minutes. I'm just trying to be detailed. =3D)


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