Daniel P Thomas

US Patent:

59864621, Nov 16, 1999

Filed:

Mar 31, 1997

Appl. No.:

8/829205

Inventors:

Daniel T. Thomas - Escondido CA
Burton M. Kuck - Escondido CA

Assignee:

Applied Data Technology, Inc. - San Diego CA

International Classification:

G06F 1520
G01R 3100

US Classification:

324771

Abstract:

A testing device to test and troubleshoot APUs that is designed to be small, rugged, light weight, and easily adaptable to many different APU applications. Using a special multi-wire cable system, test and monitor circuits are imposed between the APU control panel and the ECU and also between the ECU and the LRUs. LRU electrical circuits are subjected to short electrical pulses and the resulting current flow is monitored. Defective LRUs are detected by a very low or zero current measurement indicating an open circuit or by an excess current flow indicating a short circuit. The testing device does not include standard monitoring equipment such as voltmeters and oscilloscopes which would require calibration. Instead, the APU Tester's signal selector equipment routes a selected APU signal to the APU Tester's front panel test jacks for easy monitoring of circuit resistance and signal characteristics using standard external monitoring equipment which can be separately calibrated. The testing device provides signal buffer circuits and signal latch circuits to furnish a record indicating if signals are transmitted between the APU's LRUs.