Guru
Joined: 21/06/2018
Location: AustraliaPosts: 1190
| Posted: 03:57pm 22 Jun 2024 |
Thanks for the feedback chaps, glad they have arrived ok, should be all received by Monday I would hope. (not overseas ones unfortunately)
With Regard to the Mods for the 5V regulator, I am posting here how to use the spare pads near the sync input for the 4 pin regulators with the added zener diode (8.2 - 10V) suggested and 1K resistor. You could also just use the 3 pins that the little switching regulator would use to fit a standard 7805 style linear regulator with small heatsink and not fit the 4 pin regulator with the enable.
Extra information about 5V Mods. The linear KA78R05 regulator is not a "must do item"
the addition of the TO92 5V supply monitor parts should be adequate enough to stop the Nano codes from getting corrupted. But the LCD backlight and maybe some LEDs may still flash or flicker a few times during shutdown. The linear regulator modification if installed should cure that too. The next version of the Nano control card will have provision for the KA78R05 mod as well as the 5V supply monitor reset parts.
On the little LCD PCB the +5V reset monitor should also be fitted for code protection.
The supply monitor TO92 part that holds the Nano in reset is a simple addition to the underside of the board. The second picture shows the 3 pins highlighted to denote LHS=Gnd, Mid=+5V, RHS=RST, just check the pin out on the data sheet for the part you select. Mountint eh 5V monitor to the lCD board is almost the same ecept for the LHS pin will have to be soldered to a small area nearby with the solder resist scratched off as the same Nano pin is not grounded on the LCD board.
4 PIN LDO 5V linear regulator suggested mod. connections to be made are highlighted
5V supply monitor suggested mod. connections to be made are highlighted
And an assembly diagram showing the connections to be made, note pin 3 of regulator and R31 are joined and need to connect to the ground-plane.
WG39R7A Assy.pdf
Edited 2024-06-24 13:16 by wiseguy