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SBK_RP1 is a compact, reusable hardware module that protects low-voltage DC electronic circuits against accidental reverse battery connections. Using a P-channel MOSFET ideal-diode topology, it provides reverse polarity protection with a much lower voltage drop than a conventional series diode. An integrated LED indicates when protected output power is available.
Designed for breadboards, prototypes, and educational projects, SBK_RP1 offers a simple way to improve the robustness and reliability of battery-powered embedded systems.
- Input voltage: 2–12 VDC
- Maximum Load current: 2 A
- Maximum practical current depends on operating voltage, ambient temperature, PCB cooling, and allowable temperature rise.
- Reverse polarity protection using a P-channel MOSFET
- Very low forward voltage drop
- Protected output power status LED
- Breadboard-friendly 2.54 mm pin header
- Optimized for low-cost assembly using JLCPCB Basic components
| Pin | Description |
|---|---|
| VIN | Power input (2–12 VDC) |
| GND | Ground |
| VOUT | Protected power output |
Battery
│
SBK_RP1
│
SBK_SP1 (optional)
│
Embedded System
SBK_RP1 is installed between the power source and the electronic circuit. During normal operation it introduces only a very small voltage drop. If the supply is accidentally connected in reverse, the module automatically blocks current, protecting the downstream electronics.
- Connect the power source to VIN and GND.
- With correct polarity, the MOSFET turns on and powers VOUT.
- The voltage drop across the module remains very low.
- If the supply polarity is reversed, the MOSFET blocks sustained current flow to the protected output.
- Current flow is blocked, protecting the connected circuit.
- The output status LED indicates when protected power is present at VOUT.
- Arduino
- ESP32
- RP2040
- ATtiny
- STM32
- Battery-powered embedded systems
- Portable instruments
- Sensors
- Educational electronics projects
- Custom electronic devices
- Designed for low-voltage DC electronic circuits.
- Protects against accidental reverse polarity connections.
- Does not provide over-current or over-voltage protection.
- The output status LED indicates the presence of protected output voltage; it is not a reverse polarity indicator.
This project is fully open-source hardware. You can:
- Build your own module using the provided KiCad design files.
- Modify the design to suit your application.
- Manufacture your own boards.
If you prefer a ready-to-use module, fully assembled SBK_SP1 boards may be available in small batches on demand.
For availability, pricing, or quantity inquiries, contact:
These modules are intended for hobbyists, educators, prototypes, and small-scale projects. Availability depends on component stock and production capacity.
- SBK_FET1 – N-Channel/P-Channel FET modules
- SBK_SP1 – Soft Power Switch Module
- MémoBot – Educational memory game built using SBK_SP1 and SBK_RP1
Suggestions, bug reports, and improvements are welcome.
To report a problem or suggest an improvement, open an Issue. Pull Requests are also welcome for corrections, documentation improvements, and design changes that make the project easier to understand or build.
If this project is useful for learning, teaching, or prototyping, you can support its continued development.
Donations help fund prototype hardware, documentation, educational resources, and future open-source projects.
❤️ Support the project through PayPal
Thank you for supporting open-source educational hardware.
This project is released as open-source hardware under the CERN Open Hardware Licence Version 2 - Permissive (CERN-OHL-P v2).
You are free to study, modify, manufacture, and distribute this design, provided the terms of the license are respected.
See the LICENSE file for the full license text.
This project was designed using KiCad 10.