Abstract: A lighting device includes a controller, a memory and a wireless communicator. The controller is coupled to the wireless communicator and configured to control an emitting element according to a wireless data signal. The memory is coupled to the controller and configured to store the wireless data signal. The wireless communicator includes a wireless transceiver element and a solar cell. The wireless transceiver element is configured to receive the wireless data signal. The solar cell is configured to receive visible light and convert visible light into electric power to supply to the controller, the memory, the wireless transceiver element or the emitting element.

Abstract: A power supply includes a rectifying circuit, a power converting circuit, and a snubber circuit. The rectifying circuit is configured to convert an ac input voltage to a first dc voltage. The power converting circuit is electrically coupled to the rectifying circuit at a node. The power converting circuit includes a switching element and is configured to convert the first dc voltage to a second dc voltage by selectively turning on or off the switching element. The snubber circuit is electrically coupled to the rectifying circuit and the power converting circuit at the node. When the first dc voltage is higher than a limiting level, the snubber circuit is configured to absorb the electricity power to prevent the voltage across the switching element from exceeding a safety upper limit.

Abstract: A power supply includes a rectifying circuit, a power converting circuit, and a snubber circuit. The rectifying circuit is configured to convert an ac input voltage to a first dc voltage. The power converting circuit is electrically coupled to the rectifying circuit at a node. The power converting circuit includes a switching element and is configured to convert the first dc voltage to a second dc voltage by selectively turning on or off the switching element. The snubber circuit is electrically coupled to the rectifying circuit and the power converting circuit at the node. When the first dc voltage is higher than a limiting level, the snubber circuit is configured to absorb the electricity power to prevent the voltage across the switching element from exceeding a safety upper limit.