| 摘要 |
PCT No. PCT/GB91/01008 Sec. 371 Date Jun. 21, 1993 Sec. 102(e) Date Jun. 21, 1993 PCT Filed Jun. 21, 1991 PCT Pub. No. WO91/20172 PCT Pub. Date Dec. 26, 1991.A resonant inverter has transistor switches (20, 30) arranged to conduct current from a d.c. source (10) alternately in one direction and the other through an inductor (40) and capacitor (42). The transistor switches (20, 30) are turned on alternately by signals from secondary windings (24, 34) of a drive transformer (44) having a primary winding (45) in series with the inductor (40) and capacitor (42). To control the output power of the inverter, a control circuit (50) senses reversal of current in through the inductor (40) and capacitor (42) and turns off one of the transistor switches (30 ) a predetermined time after current reversal. Current reversal is sensed by an additional transformer (60) having a primary winding (61) in series with the inductor (40) and capacitor (42). The control circuit (50) includes a timer (52) controlling the predetermined time, which may be varied to vary the power output of the inverter. A load (80) is connected across the inductor (40 ) or capacitor (42 ) .
|
