- Jun 21, 2016
- Santa Cruz, CA
I was just following the technical documents to make LM317 output negative voltage (for u67 heater). This involved Grounding the output and the adjust pin now becomes the new output at a negative voltage... still using the same resistors to tune the output.Your schematic makes no sense to me.
This follows what RuudNL changed about my schematic above too... except then i went overkill with the capacitors lol.
In my first incarnation of the psu mod i followed what you said with this:
But then learning i needed negative voltage i just moved the filters to the new output line (adj) and flipped the polarized caps.
Ok, so I will return to my original idea of 10ohm and 1000uf RCRC for the filter. ( I accidentally got 10,000uf at the electronics store )
Is there a better idea for getting negative voltage for the heater supply? Should I just go completely unregulated and just drop down from the 20v negative side of the diode bridge?