Discussion on the control mode of LED illumination along the cutting edge

Back edge control

The rear side of the phase control dimmer, using a field effect transistor (FET) or insulated gate bipolar transistor (IGBT) device. After the phase cut dimmer is generally used as a switching device MOSFET, also known as MOSFET dimmer, commonly known as "MOS tube".

MOSFET is a fully controlled switch, which can control the opening, but also can control the switch, so there is no SCR dimmer can not be completely off the phenomenon.

The other MOSFET dimming circuit for capacitive load than SCR dimming, but because of the high cost and the dimming circuit is relatively complex, not easy to be stable. The MOS tube dimming method has not developed, SCR dimmers still occupy a large market for most of the optical system.

With the advanced phase cut dimmer than the phase cut dimmer application in LED lighting equipment, because there is no minimum load requirements, which can achieve better performance in a single, lighting or very small load but rarely used in the MOS tube light system, usually made of knob type single lamp dimmer switch, the small power after the phase cut dimmer does not apply to the engineering field.

And many lighting manufacturers to apply this dimmer on their dimming drive and lamp dimming test. And then put their dimming products to the engineering market, resulting in the project often used SCR dimming system after modulation of the phase modulated light driven situation.

The dimming of the dimming mode results in dimming, severe damage to the power supply or dimmer.

Figure: the principle of cutting along the edge of the cutting edge and the cutting edge to PWM