Distributor Pulse Reader

[mauricioscotton]

This is my first post.... =)

I'm trying to read pulses from Distributor...
What i need: The analogue pulse from coil must be converted for PIC16f877A can read this pulse.
the pulse should be ON and OFF, i'm reading state of pin RA0.

thanks anyway.

Mauricio Scotton

 

[EBM_dude]

You mean a car's distributor? What type of ignition is it using? Breaker contact or transistor?

 

[mauricioscotton]

EBM_dude, thanks for reply...

Yeah, it's from car distributor... i'm using the original Volkswagen igntion...

i'm using a NPN transistor to convert negative pulses to read...
but, my new idea is: read voltages... with a LM3914...

do you have any transistor pulse reader circuit?!

thanks anyway!

Mauricio

 

[wakibaki]

You want to read every pulse? Or just one cylinder?

You can see every pulse at the points. Connect a high resistance (1M), or resistive divider (pot?) across tha points. Measure between the chassis and the pot wiper using a high resistance (oscilloscope) to see what output you are getting.

w

 

[chris661]

Welcome to the forums.

 

[EBM_dude]

You could go for an easy one here: wire a small glow-discharge lamp and a resistor in parallel to the PRIMARY of the ignition coil. when the breaker point interrupts the current to the coil, it will create its many kV on the secondary but also like 200 VDC on the primary. This will ignite the glow-discharge lamp. Now a simple photo transistor can pick up this signal for your PIC.

 

[dangus]

Look at the schematics of tachometers and dwell meters to see how they do it. The LM2907/LM2917 data sheet and application notes are one place to start.