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. 26, 1986
Filed:
Sep. 14, 1984
Andrew M Mallinson, Salem, NH (US);
Ferranti plc, Gatley, GB;
Abstract
A constant voltage circuit has two rails 10 and 12, with one rail 12 at a variable potential V, possibly supplied by a voltaic cell. In one arm between the rails there is voltage reference means Z1, 14, with a circuit output line 16 connected thereto, and the line 16 is required to be maintained at a potential V.sub.o, corresponding to a maximum value for V. In a second arm there is provided a first resistor R1, connected to the rail 12, and in series with a transistor T2. A second, equal, resistor R2 is connected between the output line 16 and the transistor T2. Means Z2, 30, T3, causes a potential, corresponding to the variable, decreasing, potential V, to be applied between the second resistor R2 and the transistor T2. The current to the transistor T2 is constant over a wide range dV for V, by a compensating current portion dI flowing through the second resistor R2, thereby maintaining V.sub. o constant. Usually, current gain means, such as a transistor T1, is provided, in the first arm, between the output line 16 and the rail 12.