Abstract: The present invention is a transceiver and system for controlling photographic equipment. Each transceiver unit of the present invention can be pre-set as an “originating,” “remote” or “relay” unit, and regardless of which setting, each unit is capable of transmitting and receiving coded radio or optical signals. Each unit has at least one selector switch, various input and output connections, a transceiver chip, a microcontroller and associated electronic circuits. Encoded signal pulses containing channel, system, and control codes are transmitted, received and/or relayed between units. The ability to select the function of any one transceiver allows identical units to be flexibly employed as a system and readily configured by the user.

Abstract: A lockable power module is locked in position within a battery compartment of an electronic flash unit by manually displacing a pair of locking members on the module outwardly therefrom to tightly grip the compartment walls.