I'm trying to drive a LM317T with a PWM signal coming from my Arduino UNO.
Here is my circuit:
The PWM frequency is about 500Hz and I'm using a TLC2272 op amp and a LM317T regulator.
If the V_ref of the regulator is 1.25V, shouldn't I get an output voltage 1.25v greater than the adjust voltage?
When I measure V_out - V_adj I get about 2V.
What's wrong with my circuit?