That's cool! It is as well much more performant than lm331, less than half time to get stable result.
Is getting more tricky of course! the whole think i would need twice due to returning fuel line. Modern engines do have the fuel return line to keep the pressure constant. But the return line will have a lower frequency range i guess and i do not know yet how much will return during normal operation. The Teensy 3.2 will subtract the value of the return line from the supply fuel line before it will be dropped on the CAN bus (NMAE200 network).Hi
"That's cool! It is as well much more performant than lm331, less than half time to get stable result."
Might be a little premature for parts though. I have the circuit on a breadboard....still working out the filters. The 37hz requirement makes it tough. Probably change the buffer to a 2nd stage filter. Also, the output varies with the supply variations, so it probably will need a 9v regulator. More to come...
eT
Thank You!Hello again
So...here's where I think would be a good place to start. I'll leave you with this design to experiment with only because the parts might get expensive. The LM358 might be OK but depends on your requirements. The low frequency performance requirement make this tough. The low pass filter opamps need to have high CMRR (~90>), with low input offset (<1mv). The ripple voltage needs to be kept down below a millivolt. I've show an LM2917 with the zener, but since there needs to be a regulator, an LM2907 can be used instead. If you use the LM2907, you'll need to remove R5 and recalc R1. If you breadboard this, keep all leads and connections short as practical to prevent noise. BTW-The output seems to settle much quicker on the bench then in the simulation.
Good luck.
eT
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I deleted the post I wrote here before since I got the answer...It’s a 10K pot
@eetech00It’s a 10K pot And the circuit is set for 1000 Hz.
If you want full scale to be 3.3 V at 611 hz then you’ll have to recalculate
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