Four-terminal connector for measuring resistance of a pyrotechnic initiator

US4829235A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Robert Robinson · Middletown, US
• Thomas Graves · Los Altos, US
• William Chris Hoffman · Decatur, US

Key dates

• Filing date: Apr 1, 1987
• Grant date: May 9, 1989
• Expiry date: Apr 1, 2007

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R1/0416
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A four-terminal electrical connector device (40) for testing and measuring unknown resistances of initiators (11) used for starting pyrotechnic events aboard a Space Transportation System. The testing device minimizes contact resistance degradation effects and so improves the reliability of resistance measurement taken with the device. Separate and independent voltage sensing (19) and current supply (20) circuits each includes a pair of socket contacts (13-16) for mating engagement with the pins (17,18) of the initiator. The unknown resistance that is measured by the device is the resistance of the bridgewire (23) of the initiator which is required to be between 0.95 and 1.15 ohms.