The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 31, 1982
Filed:
Aug. 27, 1980
Peter F Blomley, Bishop's Stortford, GB;
International Standard Electric Corporation, New York, NY (US);
Abstract
A telephone instrument circuit including electronic components for functions such as amplifying incoming and outgoing speech signals. When the electronic transducers of each electronic instruments have to operate in parallel with a carbon microphone in another instrument, problems are likely to arise. To deal with the problem, a voltage regulator is used which includes two essentially series coupled comparator-amplifiers, the first of which is driven by the circuit's supply voltage. The second amplifier has its own reference voltage and its output varies the reference voltage V.sub.R for the first amplifier, whose output is connected to the line whose voltage is being regulated. Above a preset line current, the I-V characteristic of the circuit is almost flat while below the preset threshold it is fairly steep to enable satisfactory parallel operation.