I have a 4 rack digital that I have a 900 watt element comming in the mail, but in the meantime put together a unit to allow the Bradley controller to handle the 900 watts. It works by taking the 120 vac used to power the element & appling to the primary of a small power transformer with the secondary of 9 vac, then rectifing with a full wave bridge to get 9 vdc. This is then applied to the solid state relay (observing polarity). On test run with 500 watt element, it worked fine. A wall wart would also work for this.
When testing I took readings on the digital controller & also a single probe Manerick placed with probe about 1 inch from Bradley sensor. Started to record temps at 168 on Maverick & Bradley read 153 (15 degrees different) at 245 0n Maverick, Bradley shut off at programmed 220 ( 25 degrees different ).
Then a surprise, while the Bradley temp fell from 220 to 210 & turned back on the Maverick fell from 245 to 190 ( 55 degrees ) with probes only about 1 inch apart. Thinking about this it seems like the stainless back heats up much slower & cools off much slower & the Bradley sensor is reading the metal temp & not the air temp. If that is the case, the oven air temp is much warmer than the Bradley sensor indicates even very close to the sensor.
alanfromwis