| 摘要 |
<p>A single-stage modular modulator (10) for pulsed illumination sources uses a full-bridge converter (20) which converts unregulated DC to a 40-50 kHz carrier modulated at a frequency of a few hundred to a few thousand hertz. The modulated carrier is applied to the illumination source (66) through a step-down transformer (50) followed by a low-pass filter circuit (60) which removes the carrier. The converter (20) is controlled by a modulation control (42) which uses an instantaneous load current signal feedback (72) to follow a modulation command signal (74), and a current mode signal (76) representing the primary current of the transformer (50) to compensate for converter output variations caused by input voltage variations.</p> |
