Abstract: The board real estate consumed by a number of blocking capacitors, which are connected to the top surface of a printed circuit board to isolate circuits with different DC voltage levels while permitting a high frequency signal to pass through, and a number of metal-plated holes, which are associated with the blocking capacitors, is substantially reduced by forming the capacitors and metal-plated holes between the pins of a high-frequency connector. Forming the metal-plated holes between the pins of the high-frequency connector reduces the number of metal-plated holes in the signal path. This, in turn, substantially reduces the parasitic capacitive and inductive elements, thereby substantially improving the signal integrity of the PCB design.

Abstract: In a system for optically scanning and reading data printed in transversely extending lines longitudinally spaced apart on a document and comprising a scanning head including an electro-optical arrangement for scanning and reading the data, friction drive rollers for engaging and moving the document longitudinally past the scanning head, a motor drivingly connected to the rollers, and controls for the motor, the improvement in which the motor is a stepper motor having an output shaft which is advanced one step about its axis each time the motor is pulsed. The controls include a pulse generator, an optical system for detecting such lines of data on the document and stopping the longitudinal movement of the document, the optical system being operatively connected to the generator and effective to control the pulse output of the generator. The generator preferably provides pulses at a first predetermined frequency and pulses at a second and lower frequency.