Guru
Joined: 21/06/2018
Location: AustraliaPosts: 1156
| Posted: 11:34am 08 Jun 2024 |
I think that both Nanos should use the 12V supply option. I also think they should both be controlled by a common or separate 5V supply supervisor, The little switchmode or a 7805 regulator could power the LCDs 5V not to be confused with the LCD Nanos 5V being derived from 12V. I just saw the specs for the Nanos on board regulator and they are saying it can supply 800mA (not sure if the solder is solid at this value....) but for the LCD backlight I think it only needed about 50mA so I suspect a Nano fed from 12V can drive the LCD without a separate regulator its only around 0.35W - to be confirmed next time I am in the workshop.
I am also considering in Rev8 using a true RMS IC for the AC volts and Amps so things like the AC relay can make a disconnect decision accurately. I not sure I want the Nano to crunch numbers to get the true RMS values - I'll ask for guidance here. In the past True RMS converters were not cheap not sure if that has changed of late, will look into it.
The Boards are finished from JLPCB finally - the capacitor boards were at 67% complete & were sitting in QC for 2.5 Days like that, after everything else was finished. They would not tell me anything about why but I suspect they had to re-run them. Anyway should be picked up tomorrow & heading back here.
Edited 2024-06-08 21:48 by wiseguy