Gunner Asch wrote:


Im not sure it will be of any use..but Ive a number of Honeywell UDC2000
and UDC 2500 controllers that may be of assitance.

They are temperature/IO controllers for ovens and other heating
applications. Uses a remote termocouple and have a number of outputs
programmable


The problem with using a thermocouple is getting the thremocouple to
react faster than the plastic. A thick freezer bag is only ,004"
thick and it is really easy to over shoot the temp. if you try to use
a thermocouple.

The budget way is to use just time and trial and error. This works if
your timer is consistant and the residual heat is allowed to blead
off. Otherwise it is like making toast, the first slice tends to be a
little lighter than the ones that follow as the toaster is already
hot.

On the other hand, your controller might work if you can use a coil to
measure the amp draw of the heating element, and use that instead of a
voltage of a thermocouple. You might need an additional circuit to
translate the signal so the controler can understand it. When I get
to the control phase of the project I might run this by a electronics
whiz friend of mine.

My suspicion is that you can probably get a good seal using a timed
pulse and trial and error.

Roger Shoaf