distributor output

R.DesJardin

Does anyone know what signal a 4 cyl. Toyota engine (non-EFI)·distributor puts out for the Tach.? I don't have a scope as I'm guessing it's a changing wave. I want to make a automatic transmission shift setup using a Stamp so I can shift the three solenoids manually and also let them shift at preset RPM's. Also display the appropriate gear as well as RPM.
RD

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"If I didn't live in the middle of nowhere."

Erik Friesen

I don't know about toyota but all coils are tripped on the falling edge of a 12 volt signal. I would use npn transistor with a 10K pullup and a 10K base resistor with a 100K pull down to hook onto the coil connection. You may have to play with the resistor values a little to get consistent results. I have interfaced a stamp to ford and honda coils with no problems.(not the high voltage side) Its a very simple matter to read the pulse width. However I suspect you will find the stamp not powerful enough to do the multitasking you desire. If you can run the stamp you may wish to upgrade to the propeller as it is not that extremely difficult to learn and would easily do what you want.