| 摘要 |
The present invention relates to a power unit with a self-oscillating series resonance converter for feeding of a load. The series resonance converter comprises: two transistors TR 1 , TR 2 coupled together, which are arranged to individually be affected by a control transformer T 1 , a series connection of an inductor L 1 and a capacitor C 4 , and means to change the oscillating frequency of the transistors TR 1 , TR 2 and thereby the output voltage of the power unit. Each transistor TR 1 , TR 2 together with the series coupled discharging capacitor C 6 , C 7 or additional transistor TR 3 , TR 4 belonging thereto is connected in parallel with said inductor L 1 , capacitor C 4 and control transformer T 1 . The means to change the oscillating frequency of the transistors comprises a control oscillator OSC that in an alternating manner sends pulses that turns off the transistor TR 1 , TR 2 that conducts current and thereby the oscillating frequency of the transistors is controlled by the pulse frequency of the control oscillator OSC. |
