摘要 |
Briefly, to reduce switching stresses, employed is a high-frequency AC power source (110) and a current-limiting (ballasting) network (116). The network ( 116 ) includes a high-frequency trap ( 120 ) and an impedance transforming network (122), which is coupled to the AC power source (110) by the trap (120) and which is for connection to a load that includes at least one gaseous discharge (fluorescent) lamp or other non-linear or negative-resistance load (102). The trap, which has the parallel resonant combination of an inductor ( 130 ) and a capacitor ( 132 ), is resonant at a frequency chosen such that the switching-circuit transistor(s) (210, or 230 and 232, or 250 and 252, or 270 and 272, or 708) of the AC power source (110) switch at times when the level of the current (charge flowing) therein and/or the voltage developed there across is zero, preferably, at a frequency slightly higher than a harmonic frequency of the high-frequency AC power source ( 110 ).
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