A 12V 3A adapter is a power supply unit that outputs 12 volts of direct current (DC) at a maximum current of 3 amps. This type of adapter is commonly used for powering electronic devices such as:

• LED strips
• Small electronics
• Some routers and modems
• CCTV cameras
• Arduino and Raspberry Pi projects

Key specifications:

• Voltage: 12V (DC)
• Current: 3A (amp)
• Power: Power (in watts) is calculated by multiplying voltage and current. In this case, 12V × 3A = 36 watts.

Things to consider when choosing an adapter:

• Voltage: Ensure the device you're powering is designed for 12V input. Using an adapter with a higher or lower voltage could damage the device.
• Current rating: The adapter's current rating (3A in this case) should be equal to or greater than the required current for the device you're powering. If the device draws less current, the adapter will still function normally.
• Connector type: Make sure the adapter has the correct connector for your device (e.g., barrel jack, DC plug).