> The use of ULN2803A was based on a comercial "barebone" PLC (Only
> double side PCB no casing).
> Would a double side PCB improve the situation?
> Any tips on good PCB design practice?
> Actually I am reluctant to change my current driving technique to
> triac with zero crossing switching as the commercial PLC (Unknown
> microcontroller) could do it why I can't do it with a PIC?

        I read through your email but I see no mention of bypass caps. I recently
finished a project that had the absolute worst power supply issues I have
ever experienced. I took several drastic measures but the most effective
were: isolate the PIC power supply from the rest of the circuit (I powered
it from a different higher voltage available from the power supply and put
that through a linear regulator, while not the best power wise it resulted
in very clean power to the PIC alone), and put bypass caps RIGHT ON the PIC
pins, I soldered the bypass caps directly onto the PIC's socket pins, one
for each pair. I've done alot of PIC designs without having any power issues
but this one caught me by surprise. I had a bypass cap for the PIC but
supposedly it wasn't electrically close enough. In my case the PIC didn't
reset or hang, the CCP was just capturing at the wrong times. TTYL

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