| 摘要 |
<p>A unique ballast circuit arrangement for a low pressure discharge lamp provides an improved electrode preheat circuit which insures the same proper preheat start each time the lamp is turned on, including hot restart conditions. Electronic circuitry converts a low frequency AC input to a high frequency AC output, which is provided to the low pressure discharge lamp. A preheat circuit having a positive temperature coefficient element, a bidirectional switch, and a capacitor connected in series with both lamp electrodes, provides proper start conditions under all start conditions. Cathode quiescent losses during normal lamp operation are eliminated, thereby simultaneously improving ballast efficiency and system efficacy values of the ballast circuit arrangement and the low pressure discharge lamp. <IMAGE></p> |
