Hello,
Thank you for your input this project is very important to me and I appreciate your time.
I am currently looking for ways to draw the schematic using CAD, however in the mean time... I can explain it verbatim...
EVERYTHING is powered by the 5v on board regulator except the humidity sensor (which uses <5ma and powered by 3.3v)
Current draw of the infrared co2 sensor is 85ma at 5v and the three relays are powered by the same on board regulator, each using 50-60 ma at 5V. At times when everything is called upon at once, the MAX current draw is (60ma x 3) + (85ma) = 265 ma required from the onboard 5v regulator.
I have also read that the 5v onboard regulator is limited to the amount of current, this could very well be the problem. I do have a 5v 2000ma power supply on hand. I will try connecting the 5v to this source.
I left the circuit on overnight while both connected to the 12v source and my MacBook via usb. There were no problems. However before hand, I left the circuit on while powered by ONLY the 12v and it malfunctioned after 30 minutes.
link to 4-channel relay: