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LT77 electric speedo drive
Posted: Wed May 06, 2009 7:40 am
by ChrisJC
With the LT77 electronic speedo drive, how many pulses per rev does the transducer output?
Thanks,
Chris.
Posted: Wed May 06, 2009 8:23 am
by russell_ram
I believe it's a once per rev sine wave output. BTW it needs a low voltage supply (carrier signal) to work and modulates the output voltage. I have a wiring diag somewhere but I've just moved house so it will take some finding.
Russ
Posted: Wed May 06, 2009 7:06 pm
by ChrisJC
Just hooked it up to my oscilloscope.
It appears to be a simple switch, which goes open-circuit 8 times per revolution.
To be fair it's the Range Rover type unit which is remote from the 'box, however it seems to work the SD1 speedo just fine...
Chris.