Blue Bawls automatic LED light

Step 2: Breadboard the circuit (if you want to test it)

Construct the circuit according to the schematic shown on the previous step.

Note: Depending on the photo-cell used the 100K resistor value might need to be changed. A pot could be used to determine the optimal resistor value.

Comments

[james73]

I need help PLEASE Im want to use a 5v trnsformer to photocell to a led i got ll my parts at radio shack. led is 7000 mcd 5ma 3.3-3.6max volts Im not sue if i got the right transistor mrkings are 2n/222/a338. when i get it to work it works opposite of what i want light turns on in light and off in dark. WHAT do i need to do
                                                                    

[foto]

Ok this transistor is working fine. I just need to play with some resistors and get the lite on when its darker. The light level from the led is preventing its full potential? I also found some PNP transistors that brighten the leds as the ambient light increases. And if I knew more about electronics this wouldnt be so puzzling.