EP 2315505 A1 20110427 - Method of controlling a half-bridge circuit, and a half-bridge circuit controlled thereby
Title (en)
Method of controlling a half-bridge circuit, and a half-bridge circuit controlled thereby
Title (de)
Verfahren zur Steuerung einer Halbbrückenschaltung und damit gesteuerte Halbbrückenschaltung
Title (fr)
Procédé de contrôle d'un circuit à demi-pont, et circuit à demi-pont commandé avec celui-ci
Publication
Application
Priority
EP 09173168 A 20091015
Abstract (en)
A method of controlling a half-bridge circuit, in particular for use with lamps such as compact fluorescent lamps, is disclosed. The method is particularly useful for preventing excess power dissipation in the half-bridge transistors under mains over-voltage supply conditions. Whereas conventional methods rely on adjusting the switching frequency in response to the - measured - input voltage, the method disclosed herein relies on measurement of the mean square voltage of the half-bridge node. By controlling the switching frequency to maintain a constant mean square half-bridge voltage, the power dissipated by the half-bridge transistors is held constant independent of variations in mains input voltage. In one embodiment, the control is effected by charging a capacitor with a current corresponding to the instantaneous square of the half-bridge node voltage, and then discharging it with a current corresponding to the instantaneous square of the reference voltage. The voltage across residual charge is used to control a voltage-controlled oscillator, to modify the half-bridge switching frequency and maintain the mean square value.
IPC 8 full level
H05B 41/24 (2006.01); H05B 41/298 (2006.01)
CPC (source: EP)
H05B 41/2983 (2013.01)
Citation (search report)
- [XI] WO 9638024 A1 19961128 - PAUL JON [US], et al
- [XI] KR 20080040258 A 20080508 - D M B TECHNOLOGY CO LTD [KR]
- [Y] WO 02063756 A1 20020815 - PARK JOON-HO [KR]
- [Y] US 6930454 B2 20050816 - LOTT JOERG [DE]
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR
Designated extension state (EPC)
AL BA RS
DOCDB simple family (publication)
DOCDB simple family (application)
EP 09173168 A 20091015