LED dimming with efficiency considered

A LED dimming circuit, together with the KY converter, is presented, which is controlled based on a field-programmable gate array. Via the proposed feedback control strategy, the voltage across the linear current regulator is reduced so as to upgrade the efficiency of the overall system, with the proposed maximum error selection based on a suitable voltage turning on the diode. Aside from this, each LED string takes direct dimming, and is powered by the KY converter, which has an output inductor and hence upgrades the life of the output capacitor. Experimental results show that the efficiency based on the proposed control method is higher than that based on the traditional control one, particularly at light load.