Page 1 of 1

Question on Famicom Schematic

Posted: Thu May 05, 2016 3:30 pm
by Super-Hampster
question.jpg
Am I correct in assuming the two configurations in red squares is interchangeable? Either one will work? I imagine it might say something about it on the schematic but I don't read Japanese.

Re: Question on Famicom Schematic

Posted: Thu May 05, 2016 3:42 pm
by lidnariq
Just talking about the two from an EE point of view:

Two capacitors in parallel sum their capacitances. Two capacitors in series are the reciprocal of the sum of their reciprocals, i.e. their "daraf"s sum.

Either way, the portion of the schematic there has the same function: to adjust the exact load capacitance on the primary crystal to allow adjusting it to correct color on-screen. It's just that C22||TC1 can produce a total capacitance between 18 and 38pF, and C5-TC1 can produce a total capacitance between 0 and 4.3pF.

Either way, the specific crystal you're using will have a rated capacitance, and either topology should work, if you're using the correct size of capacitors.