Low Cost Reverse Polarity And Over Current Protection (corrected) Now

While the MOSFET stays cool, the PTC will get hot during a fault—keep it away from heat-sensitive components like electrolytic caps. To help you select the specific components, tell me: Your input voltage range? The maximum current your device pulls?

This circuit provides a robust, low-cost solution for protecting sensitive electronics from two common killers: accidental battery reversal and excessive current draw. By using a P-Channel MOSFET instead of a standard diode, you achieve high efficiency with minimal voltage drop. 🛠️ The Core Components While the MOSFET stays cool, the PTC will

Acts as the main switch for reverse polarity protection. This circuit provides a robust, low-cost solution for

The Gate-Source voltage becomes positive (or zero), keeping the MOSFET closed and blocking current. 2. Over-Current Protection The Gate-Source voltage becomes positive (or zero), keeping

Can be implemented in tiny SOT-23 or SOIC-8 packages for compact PCBs. ⚠️ Pro-Tips for Implementation Check Vgs: Ensure your MOSFET’s Gate-to-Source voltage ( VGScap V sub cap G cap S end-sub

The Gate is pulled low relative to the Source, allowing current to flow freely to the load.

Ensures the MOSFET stays "OFF" when no power is applied. ⚡ How It Works 1. Reverse Polarity Protection