Expanded Scale Voltmeter

The 723 regulator sets the low end of the scale and is adjusted by the 1K pot, connected to pin 5.  The other 1K pot sets the high end of the scale. The values given here are for a scale of 10 to 15 volts.  For other ranges the values of the1.5k and 4.7k resistors and 1K pot combination should adjusted for the low end of the scale. The 4.7K resistor and 1K pot combination should be adjusted for the high end.
 

 
 

The circuit board layout is for "Manhattan Style" construction.