Input
CI
1
0.33μF
LM7805
2
3
6
-2
LM741
+
3
4
Output
10kΩ
CO
0.1μF
IRI ≥ 5 IQ
VO = VXX(1 + R2 / R1) + IQR2
Figure 12. Adjustable Output Regulator (7 V to 30 V)
Input
Q1 BD536
IQ1
R1
3Ω
R1 = VBEQ1
IREG–IQ1/ BQ1
1
IREG
0.33μF
3
LM78XX
2
Output
IO
0.1μF
IO = IREG + BQ1 (IREG–VBEQ1/R1)
Figure 13. High-Current Voltage Regulator
Input
RSC
Q1
Q2
R1
3Ω
Q1 = TIP42
Q2 = TIP42
1
0.33μF
LM78XX 3
2
0.1μF
RSC
=
VBEQ2
I SC
Figure 14. High Output Current with Short-Circuit Protection
Output
© 2006 Fairchild Semiconductor Corporation
LM78XX / LM78XXA Rev. 1.3.0
20
www.fairchildsemi.com