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flightlead404 flightlead404 is offline
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Join Date: May 2015
Posts: 808
Originally Posted by Reanimotion View Post
non-zero voltage will be the issue as the Opto chip turns on at 1.1 volt
basically it would turn on and stay on and therefore never pulse

the floating single wire VR- option should trigger at 2.5v
ok. I did clean up all the grounds, but since the CDI doesn't ground at the block there could be some potential difference. I can easily jumper a ground strap between the two for testing. I'm pretty sure I did that, but I'll do it again.

Regarding the voltage, I was reading about the opto input, which made me think that might be the issue. Instead of building a Schmitt Trigger, which is the proper solution, I may just try a quick and dirty solution. I'll put two 1N4001 or some other si-diodes in series between the TD and the OPTOIN+. That will give me a constant current drop of about 1.4v. Add to the 1.1v voltage needed to excite the LED side of the built-in optoisolator, should give me a turn on voltage of 2.5v. That is nicely above all the noise visible on the trace I attached above.

Last edited by flightlead404; 12-29-2016 at 07:11 AM..
Old 12-29-2016, 06:19 AM
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