Dual Input Power Selector

Scenario

An off-grid security camera runs on 12V and must automatically draw from a solar panel when available and fall back to a LiFePO4 battery otherwise. This schematic uses Schottky diode OR-ing to select the higher input voltage while preventing backfeed.

Key decisions

• Use Schottky diodes for low forward drop and automatic highest-voltage selection
• Add fuses and input capacitors for protection and filtering
• Include bulk output capacitor to handle load transients

When to reuse this

Reuse for any 12V battery/solar dual-supply system up to 10A where simple automatic switchover without external control is acceptable.