Abstract: A power converter is provided that has an alternating-current (AC) to direct-current (DC) switched-mode power converter circuit that converts alternating-current power into direct-current power for powering an attached electronic device. Power can be conserved by automatically placing the power converter circuit in a low-power standby mode of operation whenever the electronic device is detached from the power converter. A monitoring circuit can be powered by a capacitor or other energy storage element while the power converter is operating in the standby mode. If the monitoring circuit detects an output voltage change that is indicative of attachment of the electronic device or if the storage element needs to be replenished, the monitoring circuit can place the power converter circuit in an active mode of operation.

Abstract: In a system that includes electronic equipment such as a computer or power adapter and that includes electronic devices such as cellular telephones, media players, and other devices, cables may be provided with wireless transceiver circuitry. Each cable may include a power path without including data lines. When a user desires to power a device, the cable may be used to connect the device to the electronic equipment. The power path in the cable may deliver power from the electronic equipment to the electronic device. Data may be conveyed between the electronic equipment and the electronic device wirelessly, using the wireless transceiver circuitry in the cable. The cable may have first and second connectors at respective ends of the cable. The wireless transceiver circuitry may be contained within the first connector or within the first and second connectors. The wireless transceiver circuitry may be identified using an identifier.

Abstract: An alternating current (AC) to direct current (DC) power converter may have a connector with a pair of power supply contacts and a pair of data contacts. An electronic device may be connected to the connector of the power converter. The power converter may supply DC power to the electronic device using the power supply contacts. The power converter may include control circuitry that has a resistor coupled across the data contacts. When the electronic device and the power converter are connected to each other, each may advertize to the other that capabilities are present that exceed industry standards. At the same time, standard-compliant discovery operations may be performed to probe the value of the resistance of the resistor that is coupled across the data contacts. When extended capabilities are discovered, extended functions may be performed including accelerated charging functions and data communications functions.

Abstract: Electronic devices may have batteries that power internal circuitry. A power converter may connect to an input-output port in an electronic device to deliver power to the electronic device. Battery charging circuitry in the electronic device may be used to charge the battery in an electronic device while power is delivered from the power converter. The power converter may have load detection circuitry. When an output load is present, the power converter operates in an active mode and delivers power to the electronic device. When the output load is not present, the power converter enters a low-power standby mode. The electronic device has switching circuitry that periodically either electrically couples or electrically isolates the input-output port from internal circuitry. When the input-output port is isolated, the power converter senses that no output load is present and enters the standby state to conserve power.

Abstract: Power converters are provided that convert alternating current (AC) power to direct current (DC) power. A power converter may have multiple ports. Each port may have an associated connector with multiple power and data terminals. When an electronic device is connected to a given port, the electronic device draws DC power from the power converter. To ensure that the capacity of the power converter is not exceeded when multiple devices are connected to the ports of the power converter, the power converter may actively monitor its ports for active loads. Load detection circuitry can determine what number of ports are active. Control circuitry can compute a per-port available DC power level based on the number of active ports and can provide this information to connected devices.

Abstract: Load detection circuitry is provided that may be used to monitor an output line. The load detection circuitry may include one or more current sensing resistors. A monitor circuit can measure voltages across the current sensing resistors to determine whether current is flowing through a load connected to the output line. In configurations with multiple different current sensing resistors, the monitor circuit can determine the amount of current that is flowing through the load based on the measured voltages. A switch may be interposed between the current sensing resistor and the output line. A current-limited voltage regulator may supply a voltage to the output line. The monitor circuit may periodically open the switch and monitor resulting voltage changes on the output line to determine whether an electronic device or other load is attached. Opening of the switch may be inhibited whenever current is sensed through a current sensing resistor.

Abstract: Electronic devices such as portable electronic devices are provided. Power converters are provided that convert alternating-current power into direct-current power for powering the electronic devices. A power converter may rectify an alternating current line signal to produce a rectified alternating current signal having peaks and valleys. The power converter may have a capacitor and transformer coupled across the rectifier circuit. Power regulation switching circuitry in the power converter or the electronic device may regulate how much power is delivered to the electronic device. Relatively more power may be delivered during the peaks in the rectified signal than during the valleys. Pulsed power delivery may be controlled using control resources in the power converter, in the electronic device, or in both the power converter and electronic device.

Abstract: A power converter is provided that has an alternating-current (AC) to direct-current (DC) switched-mode power converter circuit that converts alternating-current power into direct-current power for powering an attached electronic device. Power can be conserved by automatically placing the power converter circuit in a low-power standby mode of operation whenever the electronic device is detached from the power converter. A monitoring circuit can be powered by a capacitor or other energy storage element while the power converter is operating in the standby mode. If the monitoring circuit detects an output voltage change that is indicative of attachment of the electronic device or if the storage element needs to be replenished, the monitoring circuit can place the power converter circuit in an active mode of operation.