Sorry Jerry, I'm 180 degrees out with you. In my mind I can't get past, "when Runtz units fail, why"? Surely the guys did their homework before coming up with the circuit to reproduce in quantities. I have one failed Runtz unit and the chip itself is bad (output very low voltage). All the other components tested good.
The other thing is there are general designs available and we ask everyone's opinion but shouldn't there be more investigation first?
What voltage do the downstream components need? How accurate is the fuel gauge with a 6 volt, 7 volt or 8 volt source...maybe the voltage has less impact than we mentally perceived? Maybe the actual need is stable current rather than stable voltage? Would a resistor, choke, zener diode or combinations give a better bang for the buck, or be just as accurate and possibly have a longer lifespan than a chip circuit? Is there a need to protect against inductive kickback from the fuel gauge coils? Are there conditions where the voltage system (6 volt or 12 volt) of the truck causes lethal voltage spike to the design?
