Hello everyone,
I couldn't decide either to put this here or into repair section, but this question is not so much about the repair, but to enlighten me with it's operation. I really don't know that much about analogue tech, so this makes me a beginner
I recently took this board out of an old textile warping machine after the customer was experiencing some problems on the machine. The main suspect was this particular board.
This is a brake computer for controlling the main brake of the warping machine. It calculates the correct brake force, so the yarns stay at correct tension when the stop is applied. The main input data to the "computer" are two incremental encoders, one on main beam and one the free rolling roller driven by the yarns. The main output is 0-10V to the PWM power controller, which drives the electromagnetic brakes.
While inspecting the board something raised my eyebrows, and i would be really happy if someone could explain it to me. Op amps are all TL071, DACs are AD667JN.
I made a sketch of the analog part that drives the main output for the brake. Please excuse my CAD, it makes schematics look like they would be hand drawn
And my main question is: Why THREE DACs controlled from ONE single processor to drive ONE output via the summing OP amps?