Power Supply PCB Layout
Thought for 5 sec
Schematic and PCB description
This project is a visual demonstration of a 3-series-cell battery power system for a Raspberry Pi 5, PCA9685 PWM controller, and two MG90S servos.
Schematic operation
- Three identical 3.7 V, 2000 mAh cells are connected in series, producing 11.1 V nominal and 12.6 V fully charged.
- The 3S BMS provides cell monitoring and protection against overcharge, over-discharge, overcurrent, and short circuits.
- The USB-C 3S charger module charges the battery pack. Its terminal arrangement must match the specific BMS configuration.
- A master fuse and switch isolate the battery from downstream loads.
- The XL4015 buck converter creates a regulated 5.1 V rail for the Raspberry Pi 5.
- The Mini560 Pro creates a separate 5 V rail for the PCA9685 servo power input and two MG90S servos.
- The Raspberry Pi communicates with the PCA9685 through I²C. All circuit grounds share a common reference.
- Separating the Pi and servo supplies helps prevent servo-current transients from disturbing the Pi.
The PCB acts as a carrier and interconnection board for the prebuilt modules. Wide copper traces are used for battery and load-current paths, while narrower traces carry low-current control signals. Separate connectors and labeled rails make the intended wiring easier to understand.
Safety wording
The design includes sensible protective features—BMS protection, branch fusing, supply separation, bulk capacitance, and clearly defined power paths. However, because the exact cell discharge rating and some module specifications are unverified, it should be described as a conceptual/display design rather than a certified or production-ready UPS. The charger and BMS pinouts must be verified before any physical assembly or operation.
Make it more concise
Add safety caveat
Describe PCB layout
Add charger caution
