Nah, don't use a usb 5v wall wart.? Get one with a small barrel plug and stick a socket on the Nano. Check around your junk box for the parts.?
On Thu, 5 Dec 2019 at 5:36 PM, Bob Albert via Groups.Io<bob91343@...> wrote: Okay I tried it and it looks perfect.? I found a 7805 and will find a spot for it and energize this thing from a higher voltage.
However, the circuit seems to draw the better part of 1 Ampere so running it from 13 V would dissipate 8 Watts, too much for the little regulator.? So I have to ponder alternatives, either a pass transistor or just running it from a separate 5V source as you recommend.? There is no shortage of USB wall supplies although the proper connector is another story.
Bob
toggle quoted message
Show quoted text
On Thursday, December 5, 2019, 11:05:08 AM PST, Larry Rothman <nlroth@...> wrote:
Bob -
Please DO NOT apply 5 volts to the device if you have the battery connected directly to the power switch!!
You WILL end up with a battery fire.
The only reason the unit is working is because there is a low drop out regulator that is converting that 3.7 volts down to 3.3 volts.
HOWEVER - your SA612 mixers are no longer getting the 5 volts they need to operate with and your readings will not be accurate.
The 5v at the USB socket drives the charger/inverter chip that simultaneously charges the battery and provides 5 volts to the power switch to run the Nano.
I've used an existing forum photo and added the spot (red) where you can manually connect +5V to R40 at Pin 1 of the IP5303 chip.
But first, put the battery back where is is supposed to be connected.
you can use a barrel jack and a 5V wall adapter and you're good to go.
