Fwd: Re: REFLECTOR:Looking for suggestions about fire detection

[Jim Agnew]

Will have to post the picture on the Galery later, it is
too big.

Jim
--- Jim Agnew <jim_agnew_2@yahoo.com> wrote:
> Date: Mon, 19 May 2003 05:03:08 -0700 (PDT)
> From: Jim Agnew <jim_agnew_2@yahoo.com>
> Subject: Fwd: Re: REFLECTOR:Looking for suggestions about
> fire detection
> To: Velocity Reflector <reflector@awpi.com>
> 
> Added a low res copy of the picture.
> 
> Jim
> 
> 
> Wayne, 
> 
> This is exactly the circuit I used several years ago and
> it
> works well.  You need to keep the sensors in the 140
> degree
> C (284 F) range or a little lower since that is very hot
> for fiberglass.  I used 4 sensors on each cowl half 2
> front
> about 18" apart under the area behind the engine in case
> gas or oil ran back burning and two in the rear of the
> cowl
> just forward of the reinforcing ridge about 12" apart to
> get fire exiting the cowl.  The upper cowl has the
> sensors
> in the same place.  Obviously this should be looked upon
> as
> a “possible fire warning” circuit since a sensor or wire
> might fail.  I used #22 tefzel wire and covered all of
> the
> wire on the cowls with one fine bid leaving the sensor
> body
> exposed. 
> 
> Now for the real trick, I originally used locking plugs
> on
> each cowl to connect the wires.  I quickly found that
> this
> was a real pain and decided to make an automatic
> connector
> so I could just install the cowl haves without worrying
> about the connections.  I settled on alarm system
> window/sliding door Foil Take-off Contact switches 
> (example picture attached) that you should be able to get
> inexpensively from alarm system installers.  They have
> high
> pressure wiping nickel contacts with one or more
> “fingers”,
> depending on the make, and are very dependable.  Install
> the fixed portion on the engine bulkhead and the moving
> contact on the cowl.  It will take some trial and error
> in
> placement and mounting.  Mine are mounted on the side
> curve
> of the cowl. 
> 
> Hope this helps those planning to use this type of
> system. 
> 
> Jim 
> 
> 
> --- Wayne Owens <wamowens@bellsouth.net> wrote: Woops.
> What
> Digi-Key calls them now is Thermal Cutoffs. They list a
> bunch from Panasonic  for various temperatures in degrees
> Centigrade. Part numbers are similar to P10925-ND. 
> 
> 
> Flashing LEDs show up in a couple of places L20691-ND has
> a
> built in resistor for 13 volts 671499-ND requires a 
> 1000 to 2000 ohm 1/4 watt resistor in series according to
> how bright you want it on the panel. Don't go much below 
> 1200 ohms. 
> 
> If the attachment is too large I will post it to the
> Jamaican goose thingy. Wayne 
> 
> ----- Original Message ----- From: Ronnie Brown To:
> reflector@tvbf.org Sent: Sunday, May 18, 2003 8:53 AM
> Subject: Re: REFLECTOR:Looking for suggestions about fire
> detection 
> 
> 
> Wayne. 
> 
> How about a part number?  I did a search on Thermal at
> Digikey and got no response. 
> 
> THANKS! Ronnie 
> 
> ----- Original Message ----- From: Wayne Owens To:
> reflector@tvbf.org Sent: Saturday, May 17, 2003 6:12 PM
> Subject: Re: REFLECTOR:Looking for suggestions about fire
> detection 
> 
> 
> I used Thermal fuses (from Digi-Key) in a string 
> (series) around likely hot spots. One end is grounded and
> the other end is tied to the anode of a flashing red LED 
> (also Digi-Key)on my annunciator panel. The LED anode is
> fed from a resistor tied to positive voltage (cathode is
> grounded) but the fuse string keeps the anode low until
> one
> of them blows (overheats). That allows current to flow
> through the flashing LED to ground. You should insert a
> normally closed "press to test" switch in the string
> also.
> Wayne ----- Original Message ----- From: PVTPIL8@aol.com
> To: reflector@tvbf.org Sent: Saturday, May 17, 2003 4:18
> PM
> Subject: REFLECTOR:Looking for suggestions about fire
> detection 
> 
> 
> I've got the fire suppression worked out now were looking
> for the early detection. Anyone have some suggestions. 
> Wayne or Scott?? 
> 
> 
> 
> 
> 
> =====
> James F. Agnew Jim_Agnew_2@Yahoo.Com Tampa, FL Velocity
> 173
> Elite Aircraft Completed
> 
> 
> 
> =====
> James F. Agnew
> Jim_Agnew_2@Yahoo.Com
> Tampa, FL
> Velocity 173 Elite Aircraft Completed

> ATTACHMENT part 2 image/jpeg name=Takeoff Contact.jpg



=====
James F. Agnew
Jim_Agnew_2@Yahoo.Com
Tampa, FL
Velocity 173 Elite Aircraft Completed