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:
Dec. 20, 1988
Filed:
Aug. 10, 1987
Patent-Treuhand-Gesellschaft, Munich, DE;
Abstract
A control circuit for controlling a known active harmonic filter operating as a step-up converter in a power supply with sinusoidal network current input and a power factor of almost unity. The step-up converter comprises: a main rectifier, a storage inductance (L.sub.S), a cross-connected high-speed transistor (T.sub.Q), a diode (D1) and a power storage capacitor (C.sub.L). The high-speed transistor (T.sub.Q) is controlled by a first threshold switch (STc) whose input is controlled by a control capacitor (C12) coupled to receive a signal representative of instantaneous rectified d.c. output voltage (U.sub.E), instantaneous power output voltage (U.sub.o) and a signal representative of the charge state of the inductance. The inductance charge signal is obtained from a voltage jump (ringing voltage) between the inductance and the diode (D1) by sensing a flank of an oscillation voltage occurring at the diode by a RC circuit (R8, C10), which triggers a second threshold switch (STa) to control charge reversal and recharge of the capacitor (C12), thus determining the time instants of operation of the first threshold switch to control the cross-connected electronic switch (T.sub.Q) to conduction, and hence re-storing of electrical energy in the inductance.