Wednesday 23 April 2008


I have been browsing the workshop manual for a 93 Hilux / Tacoma and checked the vehicle and it has an electronic speedo. This is brilliant because I wont have to retrofit one.

The speedo just requires a 4 pulse per revolution input from the shaft.

There is a pulse output from the Danfoss VFD that is programmable. I will also be able to adjust the VFD output to compensate for the change in differential ratio.

This setup will require that I use closed loop control to have an accurate speedo.


Thalass said...

Interesting. What are your plans for the rest of the instrumentation?

I'm thinking of converting the tacho into an ammeter, with a positive section for regen. Not sure how to do it yet, though.

Mal said...

I will try and hook up the rev counter. The fuel, temp and oil gauge wil not be connected. The volts gauge will be connected to teh 12 volt system.

Anonymous said...

Very cool Mal!

Will you be using an opto-coupler to isolate the VFD and Speedo? Or does the Danfoss have isolated outputs already?


Mal said...

I hadn't thought about isolation but it would certainly be smart in case there are any unexpected voltage transients.

I need to see what voltages are required for the speedo to operate.