How to Take Adjustable output with LM340/78XX

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This simple circuit gives the LM340T-5 variable output voltage according to the formula:
Vout = 5v + (5v/R1+IQ)R2

Boosting the current output of the LM340T/ 78XX series
This circuit supplies regulated outputs at up to 5A. At low currents Q1 is off. Only above 600mA is it biased on.