Abstract: Probe apparatus is disclosed for in place testing of circuit boards of the type which carry electrical components interconnected at nodes accessible from at least a first side of the board. The probe apparatus may comprise a card which is attached to the circuit board under test adjacent its first side. A probe module, including signal conditioning means and a short interfacing element, is mounted on the card in close proximity to the node of interest. The signal conditioning means and interfacing element may comprise electrical decoupling and signal pick off means capable of sensing signals at the node while minimizing introduction of spurious signals thereto.

Abstract: Electrical connection apparatus is disclosed for achieving versatile connections between bus boards and electrical devices having conductive pins which extend through holes in the boards. Connections are achieved through transversely expansible conductive washers within the holes around the pins. Transverse expansion is caused by compression of individual washers along central axes of the holes, the compression being produced by expander means associated with the washers. Two expansible washer configurations are disclosed, one comprising spring material preformed with protuberances which are flattened to cause transverse expansion, and the other comprising a conductive elastomeric material.