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:
Mar. 03, 1987
Filed:
Jan. 24, 1986
Robert H Munnig Schmidt, Drachten, NL;
Lammert Ter Heide, Drachten, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A flyback converter for charging a battery (6) from different input voltages in which, during the forward interval, a linearly increasing current flows through a transformer primary winding (n.sub.1). The current is turned off by a first switch (S.sub.1) at a value dictated by switching means (3). During the flyback interval the energy stored in the transformer (T.sub.r) is supplied to the battery as a charging current via the secondary winding (n.sub.2) and a diode (D.sub.1). The voltage pulses appearing across the secondary winding during the forward intervals are applied to an integrator (11) via a third switch (S.sub.3). The integrator intergrates these voltage pulses. If the output voltage of the integrator (11) exceeds a first threshold value a threshold circuit (12) is activated and turns on a second switch (S.sub.2) to disable the flyback converter. If subsequently the output voltage of the integrator decreases below a second threshold value, the second switch is turned off again by the threshold circuit so that the flyback converter can be restarted. In this way the average value of the voltage across the secondary winding during the forward intervals is maintained substantially constant. Thus, the flyback converter constitutes a constant-power source, the power supplied to the battery (6) being constant and independent of the input voltage.