24 Dec
2017
24 Dec
'17
1 p.m.
My guess is capacitors also.
Noting they are paralleling resistors, they're probably just noise/AC the order of 0.01 uF, and not overly consequential to
understanding the
basic
circuit.
Again, one can draw it out with the above presumption and then assess
whether it makes sense or for alternative functions.
> This "SMD Code Book" should be of some value:
>
> http://www.sphere.bc.ca/download/smd-codebook.pdf
>
I am indeed drawing it out. Whether I have drawn it logically or not I am
not sure. I will check it with reference to the main input stage of the PSU,
where this board has come from. Could the reference be associated with the
input voltage auto-sensing? Or is this overly elaborate for that purpose?
That unmarked flat part does appear to have some resistance, about 390ohms
as measured in circuit, so probably the precision trimmed resistor you
suggest.
Regards
Rob