Arduino Battery Backup Charging Power Schema

The lamp positive (tleft) is the VIN on the Arduino, (accepts up to 12v and requires a minimal of 3.3v probably, ideal 5v or to 12v) and lamp negative (right) is to its ground. The 9v's on the left are rechargeable (Energizer NiCd), changing the volts lower shows the circuit refill, each switch near them simulates removing a battery (longer course of replacing even if power is out). The 9v on the right is a outlet adapter AC to DC 9v. The switch on the right simulates power outage. This circuit seems to be working out great, I had rough patches getting to here trying a circuit with similar objective from another project (totally different batteries and multiple ground anchors https://everycircuit.com/circuit/6187237305745408 ), but my changes appear to be stable preforming as intended. Non zener diodes I'm using are 1N4007 - nforystek

published 5 years ago