Home | Links | Contact Us | More About Intellectual Property | Bookmark

Search patents:

Home

Caller ID

Telephone-line-feeding-circuit-including-a-protective-device

Key telephone system paging lockout circuit

I claim: 1. a key telephone system paging lockout circuit comprising: N paging lockout printed ...

Non-linear sync signal processing circuit

In accordance with the invention, a sync signal processing circuit for use with television signals ...

Method and apparatus for providing gain control for an image intensifier tube

The present invention disclosed and claimed herein describes a method and apparatus for an image ...

***WITHDRAWN PATENT AS PER THE LATEST USPTO WITHDRAWN LIST*** *** NO IMAGES AVAILABLE***

Description:...

Method for managing and re-connecting a speech path link in a switching network

An object of the present invention to provide a call process method of a subscriber through a ...

Interdiction method and apparatus with frequency change inhibit function

An interdiction apparatus comprises common circuitry which can be shared by one or more subscribers ...

Alarm system responsive to intrusion induced phase unbalance

I claim: 1. In an alarm system, the combination that comprises: (a) first means to be placed in a ...

Visible image magnetic card

What is claimed is: 1. A visible image magnetic card comprising; a magnetic recording sheet ...

Bar gauge plotting and display system

A main object of this invention is to provide an improved electro-optical gaging method and system. ...

Security alarm system

What is claimed is: 1. A security alarm system comprising a plurality of alarm conductors each ...

Telephone line feeding circuit including a protective device

Details

Inventors: Bolus, Daniel M. A. F.; Chevillon, Jean P.; Conte, Jean C.; Philippe, Pierre D. P.;
Assignee: International Standard Electric Corporation (New York, NY)
Primary Examiner: Robinson; Thomas A.
Assistant Examiner:
Attorney, Agent or Firm: O'Halloran; John T., Morris; Jeffrey P.

A telephone line feed circuit is disclosed including a protective device which is located on the line ahead of the feeding device. The protective device reduces the voltage variations at the terminals of the feeding voltage in the event of overvoltage on the line. This advantageously protects the cross points of the switch against overvoltage.

DETAILED DESCRIPTION An object of this invention is to provide a telephone line feeding circuit overcoming the above mentioned drawbacks.
The feeding circuit according to the invention is characterized more particularly in that it contains a protective device placed in the line ahead of the dc feed voltage source, limiting the voltage swing at the terminals of the said voltage source in case of overvoltage on the line.
Other characteristics and advantages of this invention will be brought out in the following description of embodiments, the said description being related to the attached drawings in which:

Related patents

	Current sink for DPT channel unit What is claimed is: 1. Apparatus responsive to a first control signal that is one of a first state, a second state, and varying between the first and second states for ...
	Toroidal antenna In the present invention electrically small, yet self-resonant and, therefore, efficient, electromagnetic structures are disclosed. These structures may be used as ...
	Composite switch In view of the foregoing difficulties with the prior art switches, it is the main object of the present invention to provide a composite switch which comprises a main ...
	Moving coil pick-up assembly for use in a record player Accordingly, a primary object of the present invention is to provide an improved pick-up assembly which can be assembled accurately in a simple factory assembly line and ...
	Composite shielding means and mounting means for x-ray machines We claim: 1. A shielding device for an x-ray machine comprised of a transparent planar base member and a mounting means therefor: The planar base member consisting of a ...
	X-Ray filter for chest X-rays A conventional radiographic apparatus comprises (1) an object plane for an object, or patient, to be radiographed, (2) a source for a beam of penetrative radiation, i.e....
	Key telephone system and method In FIGS. 1b, 2 and 3, the improved telephone system comprises a plurality of station sets, as for example at 10, each including a plurality of key buttons 11. A set ...
	Key telephone system with multiple processor control Accordingly, it is the principal object of this invention to provide a button telephone exchange system capable of decreasing the time required for switching the ...
	Electroacoustic transducer with a piezoelectric diaphragm In order to obviate these disadvantages, the invention proposes an electroacoustic transducer having a minimum number of elements and making it possible to combine means ...
	Digital bridging apparatus for telephone conferencing system It is an object of this invention to provide a digital bridge for a telephone conferencing circuit which overcomes the many disadvantages of the prior art. It is a ...

0.024
Archive: All patents - Links Copyright (c)2006 Eipa-patents.org - All rights reserved