Communication system with variable output supply current

摘要

A system including a bus and a plurality of devices coupled thereto and configured to communicate with each other via the bus. The system further includes a power supply coupled to the bus, to power to the plurality of devices via the bus and to detect an event, and in response, alternately supply power to the plurality of devices via the bus at a first current level or at a lesser second current level. This allows additional devices to be used on a bus, even where the total power consumption of the devices would normally exceed a maximum defined by a bus architecture. This also helps allow a single gauge of wire to be used throughout a bus network (even where long lengths of wire are required) while still providing sufficient power to the devices connected to the bus.

主权项

1. A communication system comprising:
an input comprising a positive terminal and a negative terminal to receive a continuous voltage from a voltage generator, wherein the input is coupled to an output comprising a positive terminal and a negative terminal; a current regulator configure to limit the supply current provided by the voltage generator to the output to a maximum value; a communication interface connected in parallel with the output, wherein the electrical impedance between the positive terminal and the negative terminal of the output is varied to transmit data; and a control circuit configured to detect the output voltage between the positive terminal and the negative terminal of the output, and to vary the maximum value of the supply current provided by the voltage generator as a function of the detected output voltage.