Need Help: Speedometer Signal Converter

[autofanatic31]

ok thanks again. I'll post some feedback as soon as I've had it built and tested.

 

[alec_t]

The risk of over-driving the ECU could be reduced by supplying the pulses from the divider (IC pin 9) to the ECU via a 10K resistor. I'd suggest trying that first.

 

[autofanatic31]

ok, I'll do that.

 

[autofanatic31]

Just got the parts for the circuit. I can't find 1N6377G and 1N7377G. What are these parts? Are there other parts that can replace them?

 

[alec_t]

What are these parts?

They're Transient Voltage Suppressors (my bad; they should both have had the same type number....1N6377). If you can't get hold of those, try googling for "Transient Voltage Suppressor" and pick an alternative with a breakdown voltage rating of ~ 15V.

 

[autofanatic31]

ok thanks.

 

[autofanatic31]

I've already searched all the electronic parts store here, but I can't find the 1N6377, and any other replacement. Can you change it to a different part that will still make the circuit function? Thanks.

 

[alec_t]

You could use 15V zener diodes instead (with anodes connected to ground). They won't offer as much protection against voltage spikes, however.

 

[autofanatic31]

ok thanks

 

[autofanatic31]

Just tested the circuit today. It worked. Thank you very much for your help and patience.
Without your help, I won't be able to finish my project.
I'm forever greatful.

 

[alec_t]

Glad it works. Nice to know theory and practice agree