Quote from: GandalfG on July 05, 2013, 09:45:30 AM

Quote from: BenTuras on July 05, 2013, 07:58:22 AM

Quote from: BkkCoins on July 05, 2013, 07:04:10 AM

... If I added a 1of4 analog switch and used the 2 available lines then I could sequentially sense each of the 4 thermistors, allowing separate readings for each quad. I could then relay them as status values for the driver to decide what to do. IS this something that is worth added cost of a switch chip?

I would say 1 sensor for 16 chips in the center on the heatsink. The heatsink will spread the warmth more or less and a sensor in the middle will probably pick up close to the highest temp of all 16 chips.

This is better way than measure in different spot and calculate average.

1 sensor in the middle will actually always read the lowest temp of all the chips MINUS the delta T between junction and Heat sink (could be many degrees C). The BEST thermal monitoring uses one sensor per chip, and always makes critical decisions (like over temp shut-down) based upon the highest reading - not the average. Just because the average temperature is 'safe' doesn't mean that one hot chip isn't about to explode due to an over-temp condition.

Enigma