US Patent 9445470 LED control circuit with self-adaptive regulation

An LED control circuit comprises a driver, a counter, and a controller and is configured to control a plurality of light-emitting units, each of which comprises at least one LED and a switch. The driver receives an alternating-current signal to output a driving signal whereby the light-emitting units are enabled. The counter begins a count from a start number when a voltage value of the driving signal equals a base value. When the count reaches a predetermined number, the controller controls the switch of at least one of the light-emitting units, causing the LED of the light-emitting unit to receive the driving signal. When the LED of the light-emitting unit receives the driving signal, the controller detects whether the light-emitting unit is enabled and adjusts the predetermined number accordingly.