Mailing List flyrotary@lancaironline.net Message #30456
From: Wendell Voto <jwvoto@itlnet.net>
Subject: Re: [FlyRotary] Re: Fire Detector Unit
Date: Mon, 27 Feb 2006 18:55:36 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
 
----- Original Message -----
Sent: Monday, February 27, 2006 8:46 AM
Subject: [FlyRotary] Re: Fire Detector Unit

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.

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. 

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. 

Mark
   
I agree that a relay board would not be needed (I didn't even see it on the web site), however, it appears to me that it only puts out a single pulse which can be stretched by adding a capacitor.  If you wanted more on time a latching circuit would be needed depending on your alarm circuitry. An led could be driven off the open collector out put but on time would be limited by the length of the pulse, hence the need for a latching circuit.  That's the way I see it.
Wendell
 
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