Ambient Light Sensor + Comparator
Connect a transistor after the comparator to amplify the current.







simulate this circuit &ndash; Schematic created using CircuitLab

If you are using a push-pull comparator (which LM311 is not) then you may be able to remove R2 if the comparator is powered from V+ and its high output is very close to V+.

And yes, the current output of the LM311 is in the single-digit mA. This additionally means that you may need a Darlington transistor for Q1.