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Why T4 is PNP, but T3 is NPN?
Opto-Coupler will not work as-is. You should tie collector to VCC, emitter to your PIC I/O + Pull-down. Or variant of it, emitter to GND, collector to your I/O with a pull-up. Internal ones, if available on these pins, could work. Assuming the signal are 12V (or something over 5v), a simple current limiting resistor, or voltage divider could also work.
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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Okay, made sense about the Transistors. I changed the NPN to PNP because they were seemed better for the job.
I also added 10k pull-down resistors to the emitter-PIC I/O wire.
Thanks for input
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Seems you have something workable now
You can safely remove R1.
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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okay, I figured why am I using 2 more resistors than I need to. I took your advice changed programming a little and used the internal pullups, check it out.
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Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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T3 - t4
I don't think those tr's will work like that, you need 12v on base to turn off and PIC pins only go to 5v. Need to have PIC drive PNP to drive base of NPN or make tr low side switches of PNP.
don
amgen
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true...
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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