Reverse polarity is a silent killer for audio gear. Plugging in a power supply the wrong way can fry amplifiers, damage speakers, and ruin your entire audio project. But don’t worry—this is totally preventable with a simple reverse protection circuit!

⚠️ The Problem: Wrong Polarity = Instant Damage

Many audio systems, especially custom amps or portable Bluetooth speakers, don’t come with reverse polarity protection. A reversed connection from a battery or adapter can send negative voltage to sensitive ICs or transistors—often with permanent damage.

🧰 The Solution: Diode or MOSFET-Based Protection

Use a Schottky diode in series with the supply or better yet, a P-channel MOSFET for low-loss reverse protection. This blocks current when polarity is wrong but allows it to flow normally otherwise.

💡 Real-Life Example

A DIYer building a 2.1 audio amplifier connected a 12V adapter in reverse.

✅ Solution: Added a P-channel MOSFET (IRF9540) between the supply and the amp board. The next time a reverse connection happened, the system was safe!

🧮 Sample Calculation

For a 2A current, choose a Schottky diode with IF > 2A and Vf < 0.5V to minimize power loss:

P = Vf × I = 0.4V × 2A = 0.8W

🛒 Product Suggestions (Made in India)

• 🔌 P-Channel MOSFET

• 🔧 Flux Paste for clean soldering

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