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:
Apr. 28, 1981
Filed:
Aug. 04, 1978
Applicant:
Inventor:
Sava Jacobson, Van Nuys, CA (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ; G05F / ; H02P / ;
U.S. Cl.
CPC ...
179-603 ; 318317 ; 318332 ; 3183 / ; 318432 ; 323280 ; 328267 ;
Abstract
In a telephone answering device, a bistable circuit employing a single operational amplifier is used for mode switching and a voltage regulator using another operational amplifier provides regulated power to the recorder drive motor. The voltage regulator uses the input terminal abrupt threshold characteristic of the operational amplifier as a voltage reference against which the output voltage is compared. The amplifier drives a transistor connected to series regulate the voltage to the load.