Teradyne, Inc.

Mark S Hoffman

Joseph Francis Wrinn

David C Drahms

A cover attaches to a circuit board and has an inlet at one side for receiving forced air and plurality of openings on its top surface through which heat sinks mounted on the circuit board partially extend. Air is made to flow into the inlet and out the exhaust openings, thereby concentrating airflow in the vicinity of the circuit board's heat dissipative components.

Circuit board cover with exhaust apertures for cooling electronic components

Relay multiplexer circuitry for making a limited number of test channels connectable to a large number of test pins through relays connected to selected test channel nodes and test pin nodes, each test pin node being connectable to a unique combination of test channel nodes within a group of pin nodes, channel nodes and relays, the number of pin nodes connectable to each channel node being substantially uniform within a group to efficiently use channels to reduce the possibility of conflict.

Relay multiplexing for circuit testers

Circuit board analysis system, featuring, in various aspects, a probe having three equally spaced tips to simultaneously contact a straight portion of a mounted IC lead, circuitry to monitor contact between the tips and the lead, use of very low level test signals while the board is powered up, and test signal injection to determine the absolute values of internal IC resistance.

Analyzing electrical circuit boards

Circuitry for making electrical measurements with low level ac signals, featuring a transformer with a coaxial cable primary having its outer shield grounded to provide an electrostatic shield, and a probe cable for a three-tipped probe in which four wires are arranged in two twisted pairs, one tip is connected to a wire in each pair, and the other two tips are respectively connected to the remaining two wires.

Growing community of inventors

Newton Center, MA, United States of America

Mark S Hoffman