Abstract: An amplitude modulated optical analog signal transmission system with an automatic calibration process is disclosed. The system provides accurate, continuous real-time signal transmission by using two or more optical transmission channels to carry the transmission signal, with the channels automatically synchronized and switched such that one channel carries the signal while the other channel is being calibrated. At least one of the channels is carrying the signal at any time, and the switching of the channels is performed such that them is no apparent perturbation of the signal caused by the calibration process. In the steady state the calibration process reduces the DC offset and gain errors of both optical transmission channels, making their individual responses accurate and substantially identical, so that the output of either channel alone or the average of their outputs, selected at the appropriate times, provide accurate representation of the transmission signal.

Abstract: A method for mounting electrical components or wires having connections both on and off circuit boards is provided in which the component is machine inserted and flow soldered along with other parts. Leads to be connected off the board are inserted into dummy holes, i.e., holes having no metallic pads or plating, so that these leads are not bonded to the board during the flow solder process. In the final assembly stage, the unbonded leads are raised from the board and electrically and mechanically connected to a terminal of an off-board component.