must be withdrawn from the socket assembly 34 it will be recalled that the pawl and ratchet assembly 138 includes a cantilevered spring member 140 and it should be noted that this spring member 140 will resiliently ride over the periphery of the ratchet wheel 142 during counterclockwise rotation of the control knob 68 but prevent clockwise rotation of the ratchet wheel 142 and hence the shaft 72 by engaging the face of the single arcuate tooth 146 accordingly the user will be free to wind up the system 66 while the shaft 72 and its associated components will be free to unwind at the appropriate time referring again to fig5 an alternate embodiment to that of fig3 is illustrated in simplified schematic wherein the flash selection system utilizes the same components as the system of fig3 except as detailed hereinafter for convenience the same identification numerals have been used to identify components common to the embodiments of fig3 and 5 the embodiment of fig5 differs from that of fig3 mainly in that an electronic switch 168 is serially inserted into the electrical path between the positive side of the battery 104 and the wiper arm 78 in place of the electromechanical switch assembly 106 fig3 a bistable multivibrator or flip flop 170 is connected to the electronic switch 168 so as to provide alternate signals thereto at outputs 172 and 174 typically the electronic switch 168 may comprise a common transistor connected to said flip flop 170 so that its base receives biasing signals from the outputs 172 and 174 forward biasing and not forward biasing respectively the base emitter junction of said transistor a sensing network 176 is serially connected between the switch 168 and the.