摘要 |
The high voltage power supply (2) of an image intensifier (1) is operated intermittently to minimise the effect on the intensified image of magnetic and electrical interference produced by the power supply. The input capacitance (43) of the intensifier maintains the high voltage at an acceptable level when the power supply is not operating. When used in conjunction with a video camera, the power supply may be allowed to operate only during the frame sunch and/or line synch periods. A shutter may inhibit operation of the image intensifier whilst its power supply is operating. The power supply enable period to inhibit period ratio is at least 1:10, and the duration of the enable period is not more than 10 mS. |