Hi. I am using
Mean Well IRM-10-12 power supply to convert 120vac to 12vdc in order to power my project from a wall outlet.
I am using a custom-built ATmega328 board. I used a 7805 linear regulator to convert the 12v to 5v.
I am also using an ESP8266 wifi module. I use another linear regulator to convert from 5v to 3.3v.
The only other components connected are 8
NeoPixel LEDs.
The Mean Well power supply is rated for 0.85 amps. If I assume that the ESP uses 300mA, the LEDs use 150mA total, and the Arduino uses 200mA, the power supply should still be far in excess of what is necessary.
The problem is that when I plug in the ESP wifi module, the ATmega sporadically resets as if it is drawing too much power.
If I plug the board directly into a 12v power source (and bypass the Mean Well AC->DC converter) then the board works perfectly. This leads me to believe I am using my power supply incorrectly.
Here is a schematic showing how my power supply and 5v regulators are hooked up.

Any ideas would be appreciated. Thanks!