Quote:
Originally Posted by Deetman
Thanks for the taking the time to review the schematic. Second sets of eyes never hurt.
I'll take a look again at the diode current. I didn't consider the coupling ratio since I haven't really used opto-isolators before.
I noticed that too about the surface mount version of the PS2501-4 which surprised me. Other than automated manufacturing the benefits of going with the surface mount version are pretty small.
Also a great concept on the self test circuitry... I didn't really think of doing that since theoretically this has already been "proven" to work. I'll probably take the board into work once I get it and run a pulse generator on it to test the board.
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The hand soldered prototype that was slammed together made me nervous.
When I put this stuff up for people to look at, you'll see why.
However, what really made me nervous was that it is is *really* hard to get a basic piece of test equipment into the circuit, it's got wires going in multiple directions and some of the junctions are too small. Never mind the fact that on our CIMiple gear box implementations the connectors are *very* hard to get to. I wanted people to be comfortable that from end to end, the wires and the logic work as planned. This way even those that don't fully understand have the hope of testing it. After all, because of the wires...something could break even if the circuit works.
Besides I sort of hoped that people would sit down with those they are mentoring and show them what it actually does on an oscilloscope. So it's both a learning tool...and a working piece of gear.
The optocoupler probably wasn't made smaller because they'd have to change the dimension between the LED and the phototransistor. Otherwise the specifications would change.