Browse Prior Art Database

Position and Force Transducer for a Spring-Loaded Electrical Connector

IP.com Disclosure Number: IPCOM000039180D
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 3 page(s) / 28K

Publishing Venue

IBM

Related People

Chikazawa, T: AUTHOR

Abstract

Simultaneous measurement of both normal force and wipe length in a circuit card connector is made possible by a test card provided for each pin position with two piezoelectric force transducers and with an insulating bridge under the pin tab. The force transducers measure compressive forces F1 and F2 under the bridge abutments. The pin-tab normal force is F1 + F2; the position of pin-tab contact point x is calculated from the F1/F2 balance. Two measurements of x, early and late in the pin action, provide a calculation basis for measuring the wipe length. The conductivity of a spring-loaded electrical connector is a function of: 1. Wiping action of the connector pin on a mating tab of the circuit card.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 58% of the total text.

Page 1 of 3

Position and Force Transducer for a Spring-Loaded Electrical Connector

Simultaneous measurement of both normal force and wipe length in a circuit card connector is made possible by a test card provided for each pin position with two piezoelectric force transducers and with an insulating bridge under the pin tab. The force transducers measure compressive forces F1 and F2 under the bridge abutments. The pin-tab normal force is F1 + F2; the position of pin-tab contact point x is calculated from the F1/F2 balance. Two measurements of x, early and late in the pin action, provide a calculation basis for measuring the wipe length. The conductivity of a spring-loaded electrical connector is a function of: 1. Wiping action of the connector pin on a mating tab

of the circuit card. This is quantified as "wipe", the

distance between the pin-tab contact point at the

finish of the pin action and one at the start of the

pin action. 2. Normal force of the connector pin acting on the mating tab. This transducer simultaneously measures the wipe and force of a connector pin on a card mating tab in a real product condition. Fig. 1 shows the operation of piezoelectric ceramic plates 1 and 2, which act as sensors to measure force. The piezoelectric material generates a charge signal (proportional to the force applied) when the material undergoes a compressive force. The charge reading can be converted to the force reading according to the following equations: X = ____F2__ L (1)

F1 + F2

F = F1 + F2 (2)

s: start; f: finish

Wipe = Xf - Xs

= __F2f____ _ __ F2s___ L (3)

F1f + F2f F1s + F2s Piezoelectric plates 1 and 2 are fixed on a base. On top of these two piezoelectric plates, a bridge 3 with a plated mati...