US Patent 8664886 Timer-based switching circuit synchronization in an electrical dimmer

Timer-based switching circuit synchronization in an electrical dimmer is provided. The energizing of a switching circuit in a dimmer is synchronized with an AC wave to facilitate providing by the dimmer electrical power to a load. The synchronizing includes starting a timer having a predetermined timeout, responsive to receipt of a zero-crossing signal. Responsive to receipt of a subsequent zero-crossing signal prior to reaching the timeout, the timer is restarted, and responsive to expiration of the timeout, a switching circuit is energized at a predetermined firing angle with respect to the zero-crossing signal to supply electrical power to the load.