| 摘要 |
An electronic ballast system includes a first capacitor (C2) electrically coupled to the first filament (30) of a gas discharge tube (12) and becomes the power supply of the gas discharge tube (12) subsequent to both its charging and discharging operations. The collector (38) of a transistor (Tr) is connected to the first capacitor (C2). The primary winding (22) is connected to the first capacitor (C2) and the collector (38) of the transistor (Tr) in parallel relation. The transformer (t) includes a secondry winding (24) which is connected on opposing ends thereof in feedback relation to the base (44) and emitter (42) of the transistor (Tr). Pulses of opposing current polarity (122 and 124) generated through the secondary winding (24) alternately provide conducting and non-conducting states for transistor (Tr) to discharge and charge the first capacitor (C2) through gas discharge tube (12) to provide a power source for operation of gas discharge tube (12). The combination provides voltage limiting preventing the kick back voltage from the primary winding (22) to exceed a safe operating limit of the transistor (Tr) and allows use of the energy to produce visible light output instead of heat.
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