I assembled the first prototype switchboard PCB,
powered it up and.... nothing. No output voltage... well, there is...
about 2.0 Volts.
And not only that, the IC chip, inductor, and even the regulator were
all getting HOT... very HOT!
I couldn't understand why...
At first I thought maybe I made a mistake when I redesigned the PCB and
moved parts around.
So I opened up my CAD software and checking my schematic and PCB
design...
Then I noticed the IC chip was facing south on my CAD layout! I build
the prototype with the IC facing north! (which is what I usually do... I
always design with the IC notch facing north.)
So I went back to my workbench and removed the IC chip and re-inserted
it in the proper way.
Power up again, and nothing.
Hmmmm.... maybe I fried the IC chip.
So I got a new one from my tube and insert it, making sure the IC notch
is facing south.
Power up and VOILA!... we have power! The DC-DC converter is working!
Adjusted the trimmer for a 48V output and so far, looking good. No
"frying bacon" noise, nothing getting hot or warm.... everything fine
and dandy.
Some pics.
It will do 48V output for as little as 7.5V input.
Feed it 5.0V DC, and it will do 35V output.
Not bad.
Next time is marrying the switchboard and the main preamp board.
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