setting a trimpot on a power supply
To set this circuit up:


Connect the actual load to the Vo terminals (or a resistor with the same resistance value as your final load).
Connect the (+) lead of a voltmeter to the Vo terminal near the 180 ohm resistor.  Connect the (-) voltmeter lead to Ground (the lower end of sensor3).
Apply supply Ground to the negative side of the 200uF cap (also the lower end of sensor3).
Apply +12V to the fuse. 
While monitoring Vo on the voltmeter, adjust the pot for proper output voltage.