So currently I am using a phototranssitor to detect light from several IR LEDS; however, I am having some trouble. I am currently using the right side of the circuit in the picture half way down the page on this website (http://www.nerdkits.com/videos/theremin_with_ir_distance_sensor/) should be under the heading The Electronics. Anyway I have been trying for ages. I have a 5V supply, connected to the collector of the phototransistor (BPV11) in series with a 10K ohm resistor to increase the sensitivity to light, then to ground (as shown in the picture). My problem is when testing I am getting changes of MAX 100mV (milli) which is no were near my friends change of 1V to 5V with the same set up. I have tried every orientation to no prevail. Any help? And yes the LEDS are working!