mechanical device identified as the interceptor connected to the lens focusing mecchanism (Figure 1-13 A). the interceptor is moved as the lens is focused regardless of whether ambient-light or flash pictures are being taken. When flash bar is in place (S2 closed) and the gear train opens switchs S5 (Fighure 1-14), solenoid #2 is energized and pulls the interceptor into position to phycally restrict the shutter blade travel (Figure 1-13 B). Since the interceptor is controlled by the focusing mechanism, the shutter opening is related to camera-to-subject distance thus compensating for the flashbulb-to- subject distance to give proper flash exposure. As a solenoid #1 de-energizes switch S4 moves from the CB position to the CA position. This switch conects VCC to the FFA.
When the flash delay period reaches completion, the circuitry removes the holding current from solenoid #2. Since the solenoid is an electro- mechanical device, removing power from it causes a collapsing magnetic field which induces a fly back voltage. This voltage pulse is fed to the flash circuitry which then applies the firing voltage across the flash lamp.
Figure 1-13 A Interceptor link, Solenoid 2, S2 operation - Solenoid de-energized