This is the other power supply regulator circuit, is different from the previous circuit, this using IC op amp quad type MC 3401 operational amplifier from Motorola. Here is also used NPN Epitaxial Silicon Darlington Transistor MJE 800.
This circuit can provide current up to 4A at a 5V.
VO- VZ + 0.6 Vdc
NOTE :
- R is used to bias the zener
- if the Zener TC is positive, and equal in magnitude to the negative TC of the inputto the operational amplifier (> 2 0 mV/°C). the output is zero. TC A 7 0 Volt Zener will give approximately zero TC