I need to do solar street light. For my project i want the light brightness vary with the surrounding brightness. If the surrounding brightness is low, sow the light will produce more brightness and vice versa. I need to know how to make the light brightness vary with surrounding brightness. What the suitable software to simulate the circuit in order to know the efficiency and to make sure the circuit is working. anyone can help me..please

 

You need to select a device to register ambient illumination. That could be a CDS cell, a phototransistor, or a light to voltage converter.

Then you need to decide on a means of regulating the intensity of illumination. You might wish to decide on the source of the illumination as well.

 

now i wonder how to connect phototransistor to the circuit. can anyone give me example of the circuit connection. should i use battery charger controller for battery protection?

 

It would probably be a valuable exercise for you to make up a trial circuit. So far, you are the only one who knows all the details, like the nature of the street light, and so on. We can't help until you have something to show us.