RPM Reader w/ Tachometer.. Help Required!

[ericgibbs]

I am starting to concede defeat

hi,
As the guys have just pointed out the circuit looks wrong.

I'll look it over and get back to you. Can you confirm that you are using a ZD1901 interrupter or some other device.???

Whats with the defeat attitude, if you follow what we say, together we can most likely sort it out..

 

[Pommie]

Sorry, I thought you were using a pic chip. Replace "pic pin" with "tachometer input" in the above. And use 12V throughout if the tacho can tolerate it.

Mike.

 

[fireworks1]

hi,
As the guys have just pointed out the circuit looks wrong.

I'll look it over and get back to you. Can you confirm that you are using a ZD1901 interrupter or some other device.???

Whats with the defeat attitude, if you follow what we say, together we can most likely sort it out..

Thanks so much Eric, honestly.
The defeated attitude is because I have one week to get this
complete and I don't want to waste peoples on this forums time.

And I also believe that there is something wrong with
the circuit that is why I looked for outside help instead of
being told "that schematic should work".

I hope you are able to help...

 

[ericgibbs]

Thanks so much Eric, honestly.
The defeated attitude is because I have one week to get this
complete and I don't want to waste peoples on this forums time.

And I also believe that there is something wrong with
the circuit that is why I looked for outside help instead of
being told "that schematic should work".

I hope you are able to help...

OK,
If you listen and learn, you are not wasting our time, we are here because we want to help.

Look at this circuit, its yours with minor changes.

The image you see of the tacho signal is from the LTspice simulation of your circuit in action.

If in doubt, ask.

EDIT: I have used the BC547 and BC557 because of the simulation, the BC548 and BC558 are OK...

 

[fireworks1]

OK,
If you listen and learn, you are not wasting our time, we are here because we want to help.

Look at this circuit, its yours with minor changes.

The image you see of the tacho signal is from the LTspice simulation of your circuit in action.

If in doubt, ask.

EDIT: I have used the BC547 and BC557 because of the simulation, the BC548 and BC558 are OK...

The changes are so simple..
What was the output signal like with the current circuit?

Thanks soo much...

 

[ericgibbs]

The changes are so simple..
What was the output signal like with the current circuit?

Thanks soo much...

hi,
You didnt mark on the circuit where you had taken the tacho signal from.??? unless it was +12V.!!!

Look at this extract from the ZD1901 d/s.... this is the way I read it.

I hope you have not damaged the opto, check the wiring.!

 

[fireworks1]

hi,
You didnt mark on the circuit where you had taken the tacho signal from.??? unless it was +12V.!!!

Look at this extract from the ZD1901 d/s.... this is the way I read it.

I hope you have not damaged the opto, check the wiring.!

Yep, thats the way I perceived the drawing as well
and believe that I have correctly wired it.

Ill try draw up a circuit layout for the new schematic..

 

[MikeMl]

Hand draw it and use a scanner... or take a close-up pix with your digital camera.