In this case, the temp thermistor bridge is outside the oven cavity itself. The cable only passes power and the already-processed bridge delta to the heater power amp. So, there's no particular benefit from having the cable stuck to the heater wrap. (at least, I think so; my basic failure was because the cable fried and shorted power to ground) Bill Ezell ---------- They said 'Windows or better' so I used Linux.
Bruce Griffiths wrote: wje wrote: Yes, but my comment is rather specific... my oscillator failed because the heater pass transistor shorted. This sent the oven heater into full-on. The overtemp sensor is far removed from the heater. There's a ribbon cable between the driver board and the temp bridge sensor board that runs directly over the heater, not outside the oven insulation. Net result, transistor shorts, cable fries before overtemp fuse opens. There's no reason the cable should be inside the oven insulation. My rebuild fix - (after removing all the carbonized foam insulation) refoam the oven, replacing the cable and transistor, and moving it outside the foam! While I respect in general the brilliance of HP engineers, my classmate was one, this isn't one of the more intelligent decisions. Bill Ezell Bill The usual reason for running temperature sensor leads over the oven inside the insulation is to thermally shunt them to the oven reducing heat transfer to the temperature sensor via the wiring. Your modification may reduce the oven temperature stability significantly. Bruce _______________________________________________ time-nuts mailing list -- [EMAIL PROTECTED] To unsubscribe, go to [2]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. mailto:time-nuts@febo.com 2. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.