초록 ▼

A surge modification circuit controls surge current flows which may occur when a computer and AC adapter are connected. The surge current flows are controlled using active circuitry since passive circuitry, which is in place continuously, sustains large uninterrupted heating power losses in the orde

A surge modification circuit controls surge current flows which may occur when a computer and AC adapter are connected. The surge current flows are controlled using active circuitry since passive circuitry, which is in place continuously, sustains large uninterrupted heating power losses in the order of watts that are wasted over time. In one embodiment, a surge modification circuit in an AC adapter includes a control element that operates as a power analog switch with a slow transition time to reduce the steepness of a surge wavefront resulting from the connection of the output terminals of the AC adapter to a computer while the AC adapter is energized. In a second embodiment, a surge modification circuit in an AC adapter employs a pair of power converter control circuits including a main power converter control circuit for performing the power conversion and a sensing power converter control circuit for determining whether the AC Adapter is connected to a computer and informing the main power converter control circuit of the connection status so that the main power converter is disabled when the computer is not attached. In some embodiments, an optoelectronic coupler is advantageously used to communicate a message indicative of the status of a connection between the AC Adapter and the computer. The optoelectronic coupler transfers the status message using optical isolation to maintain a barrier of isolation supplied by the transformer between the computer, mutually isolating AC and DC power.

대표청구항 ▼

[ What is claimed is:] [1.] A surge protection apparatus comprising:an AC adapter having an input terminal for coupling to an AC line and an output terminal for coupling to a computer, the AC adapter including:a main AC adapter circuit including:a main primary control circuit; anda main transformer

[ What is claimed is:] [1.] A surge protection apparatus comprising:an AC adapter having an input terminal for coupling to an AC line and an output terminal for coupling to a computer, the AC adapter including:a main AC adapter circuit including:a main primary control circuit; anda main transformer coupled to the main primary control circuit; andan active control device coupled to the AC adapter for reducing high surge currents that may occur upon connecting a computer to the AC adapter, the active control device including:a sensing AC adapter circuit including:a sensing primary control circuit; anda sensing transformer coupled to the sensing primary control circuit; anda coupler for coupling a sensed power condition signal from the sensing AC adapter circuit to the main AC adapter circuit.