⚠️The Problem :

Wearables like fitness bands or smart health monitors often run on compact lithium-ion batteries. But what happens if the battery is connected in reverse? Even a momentary reverse voltage can damage sensitive ICs or microcontrollers—rendering your entire device useless.

✅The Solution :

To protect against reverse polarity, a P-channel MOSFET or Schottky diode can be placed in the power path. These components block reverse current, ensuring your circuit only sees the correct polarity—even if connections are accidentally flipped.

🚗Practical Example :

Say you’re building a wearable step counter powered by a small Li-Po cell. One day, while replacing the battery, you accidentally reverse the connector. Without protection, the microcontroller could be fried instantly. But with a P-channel MOSFET at the power input, reverse current won’t flow, and the device stays safe.

📐 Sample Calculation :

If your wearable draws 100mA and your protection MOSFET has an R_DS(on) of 100mΩ:

P=I2×R=(0.1)2×0.1=0.001W

That’s just 1mW of power loss—very efficient!

🛠️ Product Recommendation :

Look for MOSFET and Schottky Diode options here:
👉 SMARTX Prokits 

🛍️Shop now at SmartXProKits.in
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