LT77 electric speedo drive

ChrisJC · Post by **ChrisJC** » Wed May 06, 2009 7:40 am

With the LT77 electronic speedo drive, how many pulses per rev does the transducer output?

Thanks,

Chris.

russell_ram · Post by **russell_ram** » Wed May 06, 2009 8:23 am

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

ChrisJC · Post by **ChrisJC** » Wed May 06, 2009 7:06 pm

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.