Dimmers are a kind of electrical devices which used to change the lighting source of the flux of the device, adjust the intensity of illumination levels. The large capacity and constitute a system called light device. The basic principle is changing the rms current of the light source of the light source to achieve the purpose of dimming. The purpose of dimmers is to adjust the brightness of the light, by reducing or increasing the RMS voltage to promote the light which with average power produced different strength of light output. Although such equipment can be applied to various purposes, this kind of regulation aims to control lighting. Dimmers use scope: small unit size normal light switches for home lighting and high power units using the grand theatre or building lighting facilities. Small unit dimmers are usually direct control, high power using remote control system. The modern professional dimmers generally USE such control system like DMX or Ethernet digital control system.