Apparatus for sensing input voltage

The present invention is converted to input power supply, the rectification part, the first power supply (V21) and the second power source (V22) with the rectified power supply (Vr) predetermined for rectifying the input power source (Vin) of the input power source by rectifying power supply (Vr) to, the dimming interface unit and the converter section to be applied to the first lighting unit, the dimming interface to sense the state of the input power source, and a first illumination portion, the dimming interface part and the first lighting unit, wherein each of a feedback type an input for being connected with the D / D converter section relates to an electrical sensing device.