Pick a temp figure you like everything to come to a halt at. Then head for a
appliance part store and ask for a dryer safety cutout sensor at that temp
figure. They are available in either one then cut off, or off then on. The
guy behind the counter won't understand the app, but he will know about the
switch.
73, Gary...wa6fgi
----- Original Message -----
From: Jeff Blaine
To: amps@contesting.com
Sent: Sunday, November 07, 2010 8:27 PM
Subject: [Amps] time to death in the event of a blower failure
The traditional monitor for a failed blower is a air pressure sensor. But
this is harder to implement with a variable speed fan arrangement.
I was working on a fail-safe for this case and thought a solution. Wanted to
run that idea by the board to see what the comments are...
Here’s the idea...
1. The cut-out mechanism would be one of these TO220 sized bimetal switches.
They are available in a variety of trip points.
2. The switch has no electronics inside and should be RF immune.
3. The switch can be set in the chimney near the silicon wall and would not
significantly impede airflow.
4. The switch has a very low thermal mass and will switch quickly.
5. Even with a failed blower, the tube would be dissipating tons of heat and
convection would ensure heat-up of the switch.
73, Jeff ACØC
www.ac0c.com
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|