Hi all.
First, PLEASE forgive me, my electronics knowledge is poor, but I do have a HUGE interest in it...
My Question:
I am building a device to continually track the sun. The 'sensing' part is a photo diode, which I want to link up to a Moeller PLC controller.
If I link the one leg of the photodiode to a 'analog-output' of the device and the other to 'analog input', the voltage read by the PLC changes with light intensity- this system works, but I'm trying to not use any external power(is this possible?)
Second way I have set it up is to have the one leg of the photodiode the analog input, and the other connected to ground. I only get a tiny change in voltage.
I have been fiddling with a transistor, and have been pouring over a circuit diagrams. Problem is; I theoretically grasp the diagrams(to some degree) but don't then know how to apply that to my Real system(which leg is which). Symbols are one thing, but I fall short when it comes to actual components.
In really really basic terms, can some one explain which Leg of the diode i must connect to the transistor, and where must I plug it in to my PLC.
Thanks
Sebastian