gc9n:
0-10v light ballast for aquarium use
I'm not sure what a 'light ballast' is (is it anything to do with the circuit used to initiate a neon tube?) but if you're going to power the lamp via this circuit, in effect you will be discarding all the unused voltage as heat which will make it very inefficient. How much power do you need to output? Does it actually need to be an analog output - is there any possibility of using a PWM output instead?