08847571 is referenced by 5 patents and cites 478 patents.

A wireless adapter for use in a two-wire process control loop includes wireless communication circuitry and first and second terminals configured to couple in series with the two-wire process control loop. A regulator having a regulated input is coupled to the first terminal and an output. A shunt is coupled to the output of the regulator and is configured to provide power to the wireless communication circuitry. A feedback circuit is configured to control current flowing from the regulator to the shunt as a function of a loop current flowing through the two-wire process control loop.

Title
RF adapter for field device with variable voltage drop
Application Number
12/486282
Publication Number
8847571 (B2)
Application Date
June 17, 2009
Publication Date
September 30, 2014
Inventor
John A Kielb
Eden Prairie
MN, US
Agent
Westman Champlin & Koehler P A
Assignee
Rosemount
MN, US
IPC
G05B 19/042
G05B 23/02
G05F 1/00
G05F 3/16
G05F 1/613
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