| 摘要 |
A half-bridge inverter is powered from a constant DC voltage and loaded by way of an L-C circuit that has a natural resonance frequency equal to or lower than the inverter's operating frequency. A gas discharge lamp is disconnectably connected across the tank capacitor of the L-C circuit and, when indeed so connected, is provided with a current-limited high-frequency (30 kHz) voltage. The magnitude of the resulting lamp current decreases as the inverter's operating frequency is increased; which operating frequency is controlled by way of a negative feedback arrangement that causes the frequency to increase as a function of increasing magnitude of the current flowing through the tank capacitor. Thus, particularly with the lamp disconnected, the magnitude of the current flowing through the capacitor-and therefore also the magnitude of the voltage existing across it-will be regulated so as to be lower than it would be in the absence of the negative feedback.
|
