Circuit arrangement for a resonant converter and method of operating said converter
First Claim
1. A circuit arrangement for a converter (1) with switches (S1, S2) for chopping a DC voltage U1 into a chopped DC voltage U3, comprising control means for controlling the switch-on times of the switches (S1, S2), in which switch-on times of the switches (S1, S2) alternate with each other and are separated from each other by dead-time phases Ttot, and circuit elements comprising a resonant circuit having at least one capacitor (Cr) and at least one coil (Lr) for converting the chopped DC voltage U3 into an output voltage U2, characterized in that means for determining the current I flowing in the resonant circuit are provided, in that the control means comprise a comparator (24) which compares a value dependent on the current I flowing in the resonant circuit with a threshold value, and in that the circuit means control the switching of the switches (S1, S2) in dependence upon the comparison result.
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Accused Products
Abstract
The invention relates to a circuit arrangement for a converter (1) with switches (S1, S2) for chopping a DC voltage U1 into a chopped DC voltage U3, comprising control means for controlling the switch-on times of the switches (S1, S2), in which switch-on times of the switches (S1, S2) alternate with each other and are separated from each other by dead-time phases Ttot, and circuit elements comprising a resonant circuit having at least one capacitor (Cr) and at least one coil (Lr) for convening the chopped DC voltage U3 into an output voltage U2. To ensure a reliable and interference-free ZVS operation of such a circuit, a circuit arrangement and a method of operating such a circuit arrangement are proposed in which a value for the energy/charge remaining in the resonant circuit for switching the switch in the inductive mode of operation is determined and compared with a threshold value by means of a comparator (24), and in which the switches (S1, S2) are controlled in dependence upon the comparison result.
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Citations
13 Claims
- 1. A circuit arrangement for a converter (1) with switches (S1, S2) for chopping a DC voltage U1 into a chopped DC voltage U3, comprising control means for controlling the switch-on times of the switches (S1, S2), in which switch-on times of the switches (S1, S2) alternate with each other and are separated from each other by dead-time phases Ttot, and circuit elements comprising a resonant circuit having at least one capacitor (Cr) and at least one coil (Lr) for converting the chopped DC voltage U3 into an output voltage U2, characterized in that means for determining the current I flowing in the resonant circuit are provided, in that the control means comprise a comparator (24) which compares a value dependent on the current I flowing in the resonant circuit with a threshold value, and in that the circuit means control the switching of the switches (S1, S2) in dependence upon the comparison result.
Specification