| 摘要 |
A fluorescent lamp ballasting means comprises a conventional voltage doubler, which voltage doubler is adapted to operate from a regular power line AC input voltage and to supply a unidirectional output current to the fluorescent lamp. After the lamp has been started, the resulting lamp current is determined in part by the size of the capacitors used in the voltage doubler and in part by the impedance of an impedance means connected in series between the lamp and the voltage doubler. By choosing the magnitude of the voltage doubler capacitors such as to constitute the major lamp-current-determining factor, a relatively good overall systems efficacy is obtained. Lamp starting is aided by capacitively coupling the input AC voltage to the lamp in a fashion additive to the DC voltage provided by the voltage doubler-this DC voltage being coupled to the lamp by way of a rectifying means. As a result, the peak lamp starting voltage is equal to four times the peak voltage of the input AC voltage. Yet, by accomplishing the coupling of the AC voltage to the DC voltage by way of one of the lamp's pairs of terminal pins, the coupling only occurs when the lamp is present in its sockets; which implies that the open circuit socket voltages are maintained at relatively low and safe levels. Additional lamp starting aid is provided by establishing an AC voltage field between the fluorescent lamp and a starting aid electrode placed in close proximity to the lamp.
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