1X99 wrote:I'll be shopping tomorrow for a VDO tach that operates from the AC output from the alternator.
Just FYI,
I've been having a hell of a time trying to get a good enough signal from one of my alternator outputs to use on my MGL E1 (the old version with no adjustment possibilities). Tried resistors in series, ballast resistors, capacitors, ... nothing works.
It gives my good readings for the first 20-30 seconds, then it's like the signal is becoming unstable and dropping away. RPM readings go lower and lower to almost nothing...
I've tried to get a signal from my magneto P-lead as well, although more stable it seems to under indicate throughout the range, probably not a good clean signal either.
Next thing I'm going to try is using an optocoupler to generate a clean pulse off BOTH AC outputs from the alternator when crossing 0, this is a much more tidy solution and should give me nice clean signal. It is a common solution to this kind of problem, here's how to do it:
If that's doesn't work I blame the instrument and I'll get something else