The Problem : 

In robotics, reverse polarity is a common accident—especially during testing or field repairs. Plugging in your Li-ion battery the wrong way can fry microcontrollers, motor drivers, or sensors instantly. That’s a costly and frustrating mistake!

The Solution : 

For small robots, a Schottky diode on the power line provides simple protection. For higher efficiency in bigger bots, use a P-channel MOSFET wired as a high-side switch. It acts like a reverse-blocking diode but with much lower voltage drop and better current handling.

Practical Example :

Let’s say your 12V line powers a robot with an L298N motor driver and Arduino Nano. A newbie teammate connects the battery backward. Without protection, the driver and MCU die. Add a P-channel MOSFET (like IRF9540) and now, in reverse polarity, the gate-source voltage shuts off the MOSFET—saving your components.

Sample Calculation :

Using a diode with 0.7V drop and 2A load:

Product Suggestion :

Try ‘P channel MOSFET’ or ‘Schottky diode 3A’, proudly Made in India:

Shop P Channel MOSFET

Shop Schottky Diode 3A

Shop now at SmartXProKits.in!
Support our work and India’s innovation—buy from our Make in India site!