| 摘要 |
<p>An improved square current waveform arc discharge lamp ballast is disclosed, which is comprised of inductive elements, a bipolar DC supply, power semiconductors and a control circuit. The power semiconductors supplement the inductive current that is supplied to the lamp such that the resultant current to the lamp is a substantially square waveform of current. The power semiconductors operate from two DC supplies, which are regulated in such a manner that the positive supply just exceeds the magnitude of the maximum positive voltage excursion of the lamp, and the negative supply just exceeds the magnitude of the negative voltage excursion of the lamp. Due to the fact that the DC supplies are maintained just above the lamp voltage, power dissipation in the semiconductor devices is very small. A large weight savings is obtained over standard magnetic ballasts, since this technique requires the use of reduced volt-ampere rating inductive components.</p> |
