Abstract: A power supply consumes mains power and has first outputs which produce an operational voltage for controlling a CPU and a primary link interface. The primary link interface is capable of sending a mains fail message through the primary link using only power from one of the first outputs. The power supply also produces second outputs for powering circuitry not related to the transmission of this power fail message. The power supply detects loss of mains power and signals this by pulling the second outputs to a signal voltage which may be near ground during a first output holdup time. The equipment powered by this supply detects the second output changing from an operational voltage to a signaling voltage, and sends this information to the CPU, which sends a power fail message across the primary link interface during the first output holdup time.

Abstract: A power supply consumes mains power and has first outputs which produce an operational voltage for controlling a CPU and a primary link interface. The primary link interface is capable of sending a mains fail message through the primary link using only power from one of the first outputs. The power supply also produces second outputs for powering circuitry not related to the transmission of this power fail message. The power supply detects loss of mains power and signals this by pulling the second outputs to a signal voltage which may be near ground. The equipment powered by this supply detects the second output changing from an operational voltage to a signaling voltage, and sends this information to the CPU, which sends a power fail message across the primary link interface. The first output has a holdup time which maintains the first voltage at an operational level long enough for the completion of the transmission of the power fail message across the first link interface.

Abstract: A power supply consumes mains power and has first outputs which produce an operational voltage for controlling a CPU and a primary link interface. The primary link interface is capable of sending a mains fail message through the primary link using only power from one of the first outputs. The power supply also produces second outputs for powering circuitry not related to the transmission of this power fail message. The power supply detects loss of mains power and signals this by pulling the second outputs to a signal voltage which may be near ground. The equipment powered by this supply detects the second output changing from an operational voltage to a signaling voltage, and sends this information to the CPU, which sends a power fail message across the primary link interface.

Abstract: A safe external A/C adapter protecting the user against hazardous, high-voltage D/C output. High voltage is defined as any voltage in excess of 60V D/C. The adapter provides an internal remote ON/OFF circuit that automatically switches the D/C output OFF unless the output plug is seated within a mating socket disposed in an electronic device powered by the adapter. When the output plug is so seated, the hazardous voltage output is inaccessible to the user. In addition, a secondary shutdown circuit is provided that latches off the A/C input in the unlikely event that the remote ON/OFF circuit should fail. The secondary shutdown circuit is largely independent from the primary remote ON/OFF circuit, and can be implemented using control circuitry already present in the adapter. No special mechanical connectors are required.