Symmetrical regulated power supply and variable 0 to 30V 2A

This Symmetrical regulated power supply and variable power supply 0 to 30V 2A circuit does not require further explanation, which is a controlled variable symmetric source, can deliver up to 15V per line (-15 and +15), or up to 30V as a whole, for the consumption of up to 2A, but with some changes could be modified to provide up to 5A ** (or more). Transistors Q1 and Q2 should be installed on a heat sink, as well as integrated LM337 and T LM317 which is in the TO-220 package.

List of Symmetrical regulated power supply components:
T1 – Transformer suitable for primary power supply (110 or 220V) and secondary 15 +15 to 2A. **
IC1 – LM317 Integrated Circuit (ECG956)
IC2 – Integrated Circuit LM337T (ECG957)
Q1 – Transistor TIP3055
Q2 – Transistor TIP2955
Q3 – Transistor BC548 or similar
Q4 – Transistor BC558 or similar
D1 to D4 – 1N5804 or similar diodes. **
D5 and D6 – LEDs
C1 and C2 – Electrolytic Capacitors 4700uF 35V **
C3 to C6 – 0.1uF capacitors (100nF) 50V
R1 and R2 – 1000 ohms 1/2W resistors
R3 and R4 – 220 ohms 1/2W resistors
R5 and R6 – 0.5 ohm 5W resistors **
R7 and R8 – resistances of 470 ohms 1/2W
P1 and P2 – Potentiometers of 5000 ohms

5A ** Modifications for:
T1 – Transformer suitable for primary power supply (110 or 220V) and secondary 15 +15 to 5A.
D1 to D4 – 1N5809 or similar diodes.
C1 and C2 – Electrolytic Capacitors 35V 10000uF
R5 and R6 – 0.22 ohm 10W resistors