Describes electronics for two reed switches which operate the camera zoom in and out. There is also a record on/off switch operated by solenoid. The whole projects has lot of information about making your own underwater video camera from a simple handycam.
The camera record on/off is controlled seperately because when the camera goes to sleep it cannot be woken up by the remote. However pushing the record button on the camera does wake it up so a solenoid is used to press the button.??
The solenoid is a 12 volt unit running from two 9v batteries in series (18volts – but that’s fine as it’s very short duration and the batteries supply limited current). This uses another reed switch which supplies power from the batteries to the solenoid instead of being connected to the remote.
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