This project was undertaken because of the limited versatility of wired and infra red remotes. It is applicable to all digital cameras that has a remote function connector, this one was fitted to a Minolta D7 with a plug from a CD player. The plug had to be slightly modified.
The interface between the remote receiver and the camera is handled by the DIY LED's/cadmium photo cells, one for the focus and one for the trigger function. Some experimentation have to be done to establish the maximum resistance that can be placed across the camera contacts, in order for it to focus/trigger, you most insure that the photocell decreases to this resistance value when illuminated by the LED. They work like a solid state relay and draw very little current, the unit only draws about 2mA at idle and about 25mA when triggered. The major expense is the remote miniature car, they cost from around $5 to $15. The transmitter has been left intact except for a new front plate. Hopefully the rest is obvious from the photos.
NOTE: This is a project for someone with advanced electronics experience.
You will take full responsibility for any damage or loss of warranty to your camera or equipment while experimenting and when your replica of this unit is plugged in.
Receiver - Transmitter
Remote Control Receiver circuit diagram. (version 3)
RC receiver, ver 3. The antenna connector is to the upper right and on the bottom is the antenna and the camera connection plug
RC receiver, version 3 closeup
Original RC units. Dia. of X-mitter 3.25" x 1.5" thick.
This remote control is made from a mini RC toy car transmitter and receiver. The hand held control unit has only got a new front. The receiver, size of a postage stamp was mounted on a perf board with the batteries and a few other components and installed in a metal mint box. Cost less than $30. ........ Thanks for looking, Rolf