| 摘要 |
To a conventional electronic flash unit having a flash tube, a release contact, an exposure measuring circuit furnishing an exposure control signal and a terminating switch connected in series with the flash tube for automatic flash termination under control of the exposure measuring circuit, is added a first auxiliary switch connected in parallel with the capacitor storing the flash energy and connected to the release button for switching the terminating switch to the conductive state upon activation of the release button, and a second auxiliary switch connected to the output of the exposure measuring circuit for switching the terminating switch to the blocked state when the exposure control signal signifies a predetermined exposure. |
