| 摘要 |
A LED lamp comprises a capacitor Cd, a full wave rectifier D1 and a switching circuit to maintain a relatively constant DC voltage Vs to drive one or a number of LEDs connected in series D22. A switching "buck" voltage to current converter may be supplied by Vs to provide power for higher powered LED devices (see fig. 2). Protection against transients may be provided by Triac Q1 and sense resistor Ri as well as PTC resistor Rp. The LED lamp may also incorporate other features such as automatic switching by sensing ambient light, dimming, variable random switching to simulate occupancy and occupancy detection. The lamp may also have provision for colour filers to be fitted. |
