Abstract: An optical isolator is provided. The optical isolator includes a printed circuit board having a first surface and a second surface opposite the first surface. The printed circuit board has a recess extending only partially through the board. The first photoelement has an active surface and is mounted relative to the first surface of the printed circuit board. A second photoelement has an active surface and is mounted relative to the second surface. The second photoelement is configured to interact with the first photoelement. At least one of the first and second photoelements has its active surface disposed at least partially in the recess. A portion of the printed circuit board is interposed between the first and second photoelements.

Abstract: An industrial process variable transmitter includes a process variable sensor configured to sense a process variable. Measurement circuitry is coupled to the process variable sensor and provides a measured output as a function of the process variable. Output circuitry includes a loop connection configured to couple to a process control loop. An optical sensor receives the measured output from the measurement circuitry. A switching device applies pulses to the process control loop in response to an output from the optical sensor. Power supply circuitry powers the optical sensor, a comparator, and/or the switching device with power received from the process control loop and loop connection.

Abstract: An industrial process control field device includes a process variable transducer configured to sense or control a process variable. Field device circuitry is configured to couple to the process variable transducer and communicate information related to the process variable to another location. The field device circuitry includes an optical isolator having transmit circuitry on a first side of a galvanic isolation configured to transmit an optical signal which is pulsed on and off across the isolation. Receive circuitry is located on a second side of galvanic isolation and configured to receive the optical signal with an optical sensor. The optical sensor enters an “on” state when it receives a pulse and is otherwise in an “off” state. The receive circuitry provides a secondary side output based upon the received optical signal. The receive circuitry enters in a low power state when the optical sensor is in the “off” state.

Abstract: An optical isolator is provided. The optical isolator includes a printed circuit board having a first surface and a second surface opposite the first surface. The printed circuit board has a recess extending only partially through the board. The first photoelement has an active surface and is mounted relative to the first surface of the printed circuit board. A second photoelement has an active surface and is mounted relative to the second surface. The second photoelement is configured to interact with the first photoelement. At least one of the first and second photoelements has its active surface disposed at least partially in the recess. A portion of the printed circuit board is interposed between the first and second photoelements.

Abstract: An industrial process variable transmitter includes a process variable sensor configured to sense a process variable. Measurement circuitry is coupled to the process variable sensor and provides a measured output as a function of the process variable. Output circuitry includes a loop connection configured to couple to a process control loop. An optical sensor receives the measured output from the measurement circuitry. A switching device applies pulses to the process control loop in response to an output from the optical sensor. Power supply circuitry powers the optical sensor, a comparator, and/or the switching device with power received from the process control loop and loop connection.

Abstract: An industrial process control field device includes a process variable transducer configured to sense or control a process variable. Field device circuitry is configured to couple to the process variable transducer and communicate information related to the process variable to another location. The field device circuitry includes an optical isolator having transmit circuitry on a first side of a galvanic isolation configured to transmit an optical signal which is pulsed on and off across the isolation. Receive circuitry is located on a second side of galvanic isolation and configured to receive the optical signal with an optical sensor. The optical sensor enters an “on” state when it receives a pulse and is otherwise in an “off” state. The receive circuitry provides a secondary side output based upon the received optical signal. The receive circuitry enters in a low power state when the optical sensor is in the “off” state.