cdsumlin

Hi, and thanks in advance for any help. I am building a crank sensor to interface with my computer. The part I needed is obsolete, so I ordered the substitute part suggested. Unfortunately I missed something and the wireing from the "opto-reflective IC" is different. I need help putting this circuit together. I need a pulse output, neg or positive, as a reference. this is the original circuit and part.



the part I recieved, opd770tz is:

http://www.optekinc.com/pdf/OPB770T.pdf

what type of circuit do i need to make this work.
Thanks again, and Merry Christmas.

ericgibbs

hi,
I make it this change.

Does this help?

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

cdsumlin

I'l try it tonight, thanks Eric.

cdsumlin

using a 330 ohm r3 works, but the rise/fall times may be slow, have to experiment now, thanks for your help.

ericgibbs

hi,
Working from +5V, with the Emitter having a forward voltage drop of 1.8V, leaves only 3.2V across the 330R, so the emitter current is only 10mA.
Use a 150R emitter diode resistor, to give 21mA, this will increase the response/sensitivity.[ the emitter is rated upto 40mA]

Lets know how it goes..

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/