| 摘要 |
A variable duration photoflash network includes a gas discharge flash tube connected through an SCR to a charge capacitor and a transformer simultaneously applies a triggering signal to the SCR gate and the flash tube trigger electrode. A timing network includes an RC circuit whose resistor is a photoconductor and is initiated and energized with the ignition of the flash tube by the voltage developed across an inductor in series with the flashtube, which voltage charges a capacitor through a rectifier. The RC timing capacitor after the timed interval effects the triggering of an SCR which connects a voltage source across the first SCR in series opposition with the charge capacitor to open the first SCR and extinguish the flash tube. |
