🔍 The Problem :

Smart plugs require a compact, efficient, and safe low-voltage power supply to drive Wi-Fi modules and relays. Beginners often use bulky or unstable power adapters that generate heat or drop voltage under load, causing the plug to crash or behave erratically.

🛠 The Solution :

The ideal approach is to use a buck converter or a low-dropout linear regulator (LDO) to step down from mains AC (via an isolated SMPS module) to 3.3V or 5V. This ensures stable power for the microcontroller and relay coil. Always choose components rated for low ripple and compact form factor.

💡 Practical Example :

Let’s say you’re designing a smart plug using an ESP8266 module and a relay. Your circuit needs 3.3V at 250mA (ESP) + 80mA (relay), totaling 330mA. A 5V-to-3.3V buck converter rated at 500mA easily handles this, with headroom for spikes.

📐 Sample Calculation :

Power = Voltage × Current = 3.3V × 0.33A = 1.089W

Ensure your power supply is rated for at least 1.5W output to maintain stability.

🛒 Product Suggestion :

Try these trusted Made in India products:

• Buck Converter Module

• LDO Regulator

• 👉 Shop now at SmartXProKits.in
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