I am trying to create a very simple circuit using a CDS photo resistor. The situation is simple, I need a circuit to be connected when its light, disconnected when its dark. The photocell will sit in complete darkness, when a camera flash is fired, I want the photocell to simply connect a circuit which will then trigger other flashes. The flash circuit doesn't carry any voltage, it just needs to be completed. Basically, I need the two photocell to simply connect two wires when its light and disconnect them when its dark.
I am using this CDS photo cell: https://www.creatroninc.com/product/7mm-light-dependent-resistor-photo-resistor/?search_query=light+sensor&results=60
This is my first experience with one of theses Photo Resistors LDR and I thought it would be really simply but I'm striking out this morning. Thank you!
Best Answer
As others have correctly said, a photo-diode would be the right part.
You can try something like this:
simulate this circuit – Schematic created using CircuitLab
You need to choose a suitable opto-isolator for your trigger output requirements. That needs a comparator with a suitable output drive for it. As I don't know your trigger output requirements, I've left those.
The pot' adjusts the current at the trip point between 10 uA and 2 mA or thereabouts.