XD-621 Induction Touch Switch

Overview

The XD-621 Induction Touch Switch is a capacitive touch-based switching module designed to control AC loads (mainly lighting) through non-contact touch sensing.

• Works through insulating materials like:

  • Glass

  • Acrylic

  • Plastic

  • Ceramic

   

• Commonly used in mirror lights and concealed switch panels

It is an isolated touch switch, meaning the user is electrically separated from the high-voltage circuit.

Working Principle

• Uses capacitive sensing (induction touch)

• Detects change in capacitance when a finger approaches the touch point

• Internal circuit processes signal triggers ON/OFF output

• Includes:

  • Low-noise programmable gain amplifier (PGA)

  • Internal signal conditioning circuit

    Electrical Characteristics

    • Operating Voltage:

      • AC: 170V 240V

      • DC version: 6V 12V

       

    • Max Load Power: ~500W

    • Max Current: up to 7A

    • Frequency: 50 / 60 Hz

     

    Output Characteristics

    • Type: ON/OFF switching output

    • Controls:

      • LED lamps

      • Fluorescent lamps

      • Household appliances

       

    • Acts as a single-pole switch (SPST behavior)

     

    Functional Behavior

    • Touch toggles state:

      • First touch ON

      • Second touch OFF

       

    • Can sense touch through a defined touch point (910 mm diameter)

    • Requires proper alignment of sensing pad for reliable detectionMounting: Behind surface (e.g., mirror backside)

    • Requires:

      • Removal of reflective coating at touch point (for mirrors)

      • Proper alignment of sensor pad

       

    • Compact module with separate touch electrode head

     

    Internal Features

    • On-chip oscillator (no external components required)

    • Built-in noise filtering

    • High interference immunity (reduces false triggering)

    • Electrical isolation for safety

     

    Key Technical Features

    • Capacitive (induction) touch sensing

    • Works through insulating materials

    • High-voltage AC load control

    • Built-in signal amplification and filtering

    • No mechanical wear (solid-state switching)

    • Compact and concealed installation

     

    Advantages

    • No physical buttons long lifespan

    • Aesthetic (hidden behind surface)

    • Resistant to dust and moisture (indirectly, due to no openings)

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    Limitations

    • Requires correct installation (alignment critical)

    • Sensitivity affected by:

      • Thickness of surface

      • Material type

       

    • Not suitable for very thick or metallic surfaces

    • Works mainly as simple ON/OFF (no dimming)

     

    Technical Summary

    The XD-621 is a mains-powered capacitive touch switch module that:

    • Detects touch through insulating materials

    • Controls high-voltage loads safely

    • Is optimized for embedded, hidden switch applications (like mirror lighting)