Ok, so obviously the first SPST switch operates power to the sensor, but what does the DPDT switch turn on and off? Also, can someone tell me how the unit triggers the camera to take a picture. Just curious, I think it will help me figure this out.
Yes, there are a number of ways you can wire the switches in your camera. For example, mine is wired so that an LED lights whenever the sensor picks up movement. It seems to catch the attention of game. They're often caught looking at the camera when it snaps the picture.
I use the spst switch to turn the power on and off to my unit. I have my DPDT switch set up for a walk/test LED. I set my camera up on the tree I have chosen, switch the switch to the "LED", and then walk around in front of my camera, and every time my PIR (passive infared) detector picks up motion/heat my LED lights up, that way I can determine where the "beam" is hitting, without wasting a bunch of pictures. Once I like the setup, and am satisfied that my detector will pick up motion on the trail I am setup on, I flip the switch to the other side, wich is "arm", or "camera", now you are ready to snap a picture. I can't tell you exactly how the P.I.R works, only that it senses a combination of heat and motion, by the use of a beam, which is focused through the "fresnal lense". Tinhorn, archilocus, and a few of the others could tell you exactly how the P.I.R works. Good luck on your project.
N Georgia Taxidermy, there are others that can give you a better statement of how it works but I will attempt to do so. If I understand it correctly as my buddy explained it to me. Never used a relay till I build one of theses so here goes. You have the info already on the SPST switch. I also build mine the way h2o does his. When the PIR (RS) picks up movement it puts out a voltage signal to the led (the old speaker position) which causes the led to come on if you have the DPDT in the led position, if you have the DPDT in the Camera postion...the signal going thru the large IC (pin 2) causes the Relay to "close" connecting the wire from DPDT switch to the relay and the wire from the bottom of the relay to the camera connections. This closes a "loop" in that wiring circle which shorts the camera (pins 4,5,6). No voltage here but it's the same as taking the two or three wires coming out of the camera and shorting them together. "Man I hope I explained that right!" Correct me people if that's wrong. bat