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Test Apparatus for Circuit Module

IP.com Disclosure Number: IPCOM000086733D
Original Publication Date: 1976-Oct-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Bryan, RE: AUTHOR [+3]

Abstract

This apparatus detects failures in an apparatus for a controlled temperature test of a circuit module (not shown). The apparatus for the temperature test includes a resistance heater 2, a power supply 3, and a connecting circuit that includes two series switches 4 and 5. The heater 2 is arranged to heat a dielectric liquid that contains the circuit module under test. A temperature controller 7 operates a relay 8 that opens and closes contacts 4 as the temperature of the dielectric liquid rises and falls about a preselected value.

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Test Apparatus for Circuit Module

This apparatus detects failures in an apparatus for a controlled temperature test of a circuit module (not shown). The apparatus for the temperature test includes a resistance heater 2, a power supply 3, and a connecting circuit that includes two series switches 4 and 5. The heater 2 is arranged to heat a dielectric liquid that contains the circuit module under test. A temperature controller 7 operates a relay 8 that opens and closes contacts 4 as the temperature of the dielectric liquid rises and falls about a preselected value.

Contacts 5 are normally open and are held closed when a relay 9 is energized in response to a signal from an AND circuit 10. AND circuit 10 receives inputs from four differential amplifiers 12, 13, 14 and 15. Relay 9 is de- energized to open contacts 5 when the voltage at the output of any one of the differential amplifiers falls from a positive value that represents a logical "1" or when power fails.

A resistor 17 carries a current established by variable resistor 18 and a voltage source 19, and the current in this resistor is to be maintained within predetermined limits for the satisfactory operation of the test. A variable resistor 21 and a fixed resistor 22 provide a voltage on a line 23 that is proportional to the current in resistor 17. Differential amplifier 12 receives this voltage at its minus input and thereby maintains a "1" logic level at its output so long as the voltage at point 23 is below a value that is established by the potential at the plus input and by the ratio of resistors 26 and 27. Differential amplifier 13 is similarly connected to maintain its output at a "1" logic level so long as the voltage l...