Hi,
So I'm trying to design a phototransistor circuit where by when an object comes near a light comes on - its going to be applied to a beer pong table.
I Designed this circuit originally:
with an R2 of around 50 ohms and R1 of around 100 ohms (I tried higher resistances which I found increased sensistivity but not brightness)
My problem was that the white LED never got bright enough even with IR led pointed directly at the phototransistor
These are the parts used:
Phototransistor: Osram Opto SFH 310 FA 50 ° Infrared Phototransistor, Through Hole 3mm Package
IR LED: Osram Opto LD 271 IR LED, 950nm, 2-pin Through Hole T-1 3/4 (5mm)
So I thought it might be wise to use a transistor to amplify the current to the white LED like such:
I tried this with a transistor I had, but the white LED remained on, assuming the circuit design is legit, I'm not sure how to decide on which transistor to use?
Any help would be greatly appreciated.
Thanks