GPI coverage and content

You can use Global Patent Index (GPI) to carry out detailed searches in the EPO's worldwide bibliographic (DOCDB), legal event (INPADOC) and full-text data sets, and download or visualise the search results for statistical analysis.

Current content: 157 117 910 patent documents

This week's update (12/07/2024 12:00 CET):

139 301 new documents added

1 340 825 documents amended

GPI key values

Run regular monitoring (e.g. monthly or quarterly) of technical areas or companies

Use built-in charts to visualise technical trends and patenting activity of companies

Choose the data you want to see and download to focus on what you are interested in

Run data quality assessments to measure the risk of incomplete search results

EP 0221324 B1 19910522 - SIGNAL TRANSDUCER

Title (en)

SIGNAL TRANSDUCER

Publication

EP 0221324 B1 19910522 (DE)

Application

EP 86113180 A 19860925

Priority

CH 432685 A 19851007

Abstract (en)

[origin: US4720665A] A transducer for converting electrical input signals into an electrical or mechanical output. The transducer employs a circuit for producing a negative source impedance and a winding cooperating with the circuit. The winding has first and second parts connected end to end. The ratio of the induced electromotive forces developed across the first part relative to that of the second part differs from the ratio of the ohmic resistance of the first part relative to that of the second part.

IPC 1-7

H03F 1/34; H04R 3/08

IPC 8 full level

H04R 3/00 (2006.01); H04R 3/08 (2006.01)

CPC (source: EP US)

H04R 3/002 (2013.01 - EP US); H04R 3/08 (2013.01 - EP US)

Designated contracting state (EPC)

CH DE FR GB LI

DOCDB simple family (publication)

EP 0221324 A1 19870513; EP 0221324 B1 19910522; DE 3679373 D1 19910627; US 4720665 A 19880119

DOCDB simple family (application)

EP 86113180 A 19860925; DE 3679373 T 19860925; US 91437286 A 19861002