Energy delivery on paths used for communnication

Abstract

Systems and methods for delivering energy on a bus used for communication between devices are provided. Systems and methods dynamically provide a predetermined recovery time between communication messages calculated from forward and response message types and/or length, and a model of the energy reserve in the network devices to allow time for energy storage circuits in the devices to charge. In addition or alternatively, systems and methods provide an extra recovery time between messages to allow the bus voltage to recover from a fold-back mode and/or include an extra current limit circuit to increase a power supply current when the combined energy required by the network devices is greater than a current limit on a power supply.

What is claimed is: 
     
         1 . A system comprising:
 a bus;   a plurality of devices coupled to the bus and configured to communicate with each other via the bus via one or more messages; and   a master controller coupled to the bus and configured to supply power to the plurality of devices via the bus and to control communication between the plurality of devices, wherein the master controller is further configured to monitor a voltage on the bus and cause the plurality of devices to wait, in response to the voltage, for an extra recovery time after a first message is communicated from a first device in the plurality of devices to a second device in the plurality of devices to allow the voltage to return to a first level from a second level, the second level being lower than the first level.   
     
     
         2 . The system of  claim 1 , wherein the master controller further comprises an extra current limit circuit configured to increase an output current limit for the power supplied by the master controller in response to a control output of a control circuit, the control output being provided by the control circuit in response to the voltage on the bus. 
     
     
         3 . The system of  claim 2 , wherein the extra current limit circuit comprises a metal oxide field effect (MOSFET) transistor switch, and wherein the control output is coupled to a gate of the MOSFET transistor switch. 
     
     
         4 . The system of  claim 1 , wherein the first message is a response message communicated in response to a forward message from the second device and wherein the second message is a next forward message communicated from the second device. 
     
     
         5 . A system comprising:
 a bus;   a plurality of devices coupled to the bus and configured to communicate with each other via the bus via one or more messages; and   a master controller coupled to the bus and configured to supply power to the plurality of devices via the bus and to control communication between the plurality of devices, wherein the master controller comprises an extra current limit circuit configured to increase an output current limit for the power supplied by the master controller in response to a control output of a control circuit, the control output being provided by the control circuit in response to a voltage on the bus.   
     
     
         6 . The system of  claim 5 , wherein the extra current limit circuit comprises a metal oxide field effect (MOSFET) transistor switch, and wherein the control output is coupled to a gate of the MOSFET transistor switch. 
     
     
         7 . A method of delivering energy to a plurality of devices via a bus that is also used for communication between the plurality of devices, the method comprising:
 sending a forward message from a first device in the plurality of devices to a second device in the plurality of devices;   sending a response message from the second device in response to the forward message;   monitoring a voltage on the bus; and   waiting for an extra recovery time after the response message in response to the voltage to allow the voltage to return to a first level from a second level, the second level being lower than the first level.   
     
     
         8 . The method of  claim 7 , further comprising:
 increasing an output current limit for power supplied on the bus in response to the voltage.   
     
     
         9 . A method of delivering energy to a plurality of devices via a bus that is also used for communication between the plurality of devices, the method comprising:
 monitoring a voltage on the bus; and   increasing an output current limit for power supplied on the bus in response to the voltage.   
     
     
         10 . The method of  claim 9 , further comprising providing a control output in response to the voltage on the bus; and
 wherein increasing an output current limit comprises increasing the output current limit in response to the control output.