Typically, no additional resistor is needed in series with the diode in the backup OR‑ing path. The diode itself prevents reverse conduction and provides the needed isolation between the bus supply and the net rail. Adding a resistor could introduce an extra voltage drop that might affect the voltage presented at the net rail.
Of course, if you encounter issues like inrush current or need further current limiting under specific transient conditions, then you might consider a very low-value resistor. However, in most designs, connecting the diode directly is standard practice.
Would you like further clarification on any part of the design?
Yes, for a complete simulation it's a good idea to add a load to the net rail. A load resistor (or any representative load element) will help you analyze how the circuit behaves under current draw conditions, including the voltage delivered to the load and any potential voltage drops in your OR-ing path.
Would you like any recommendations on load resistor values for typical simulations?
General Purpose Thick Film Standard Power
and High-Power Chip Resistor
47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film
Features:
- RMCF – standard power ratings
- RMCP – high power ratings
- Nickel barrier terminations standard
- Power derating from 100% at 70ºC to zero at +155ºC
- RoHS compliant, REACH compliant, and halogen free
- AEC-Q200 compliant
A momentary or non-latching switch which causes a temporary change in the state of an electrical circuit only while the switch is physically actuated. SWITCH TACTILE SPST-NO 0.05A 24V