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. 09, 2013
Filed:
Sep. 08, 2008
Chuntao Zhang, Shenzhen, CN;
Xiaofei Zhang, Shenzhen, CN;
Xueli Xiao, Shenzhen, CN;
Liebert Corporation, Columbus, OH (US);
Abstract
The present invention relates to a control method for a soft switch circuit in a switch power supply, which controls first and second main power switch devices to be turned on and turned off constantly to generate an alternating main power filter current, and controls forward and backward auxiliary switch devices to be turned on and turned off to generate an intermittent alternating resonant current across a resonant branch in the same direction as the main power filter current to thereby achieve zero-voltage turn-on of the first and second main power switch devices; and further controls the forward and backward auxiliary switch devices to be turned on and turned off to generate compensation currents across the resonant branch in the opposite direction to the alternating main power filter current in at least a period of time during resting of the resonant current to thereby accomplish a charging and discharging process of resonant capacitors in a dead time. Thus, a freewheeling diode can be turned on normally, so that it is possible to avoid a damage to the devices due to an impact current and a spark voltage resulting at zero crossing of the current in the soft switch circuit.