Regular circuit of regulators have been good if the ripple voltage is small, but there is a problem of stability. If the voltage PLN rise /down, then the output voltage is also will be rise /donw. regular circuit of regulators, if the current of the larger, the dc voltage output is also down. For some applications this voltage change will very disrupt.
Rangkaian Regulator menggunakan Op-Amp
Technical regulations that better is to use the Op-Amp for a drive-transistor Q. Dioda zener here do not give directly to the bait transistor Q, but as a reference voltage for the Op-Amp IC1. Feedback on the negative pin Op-amp is a snippet from the voltage regulator out, namely:


Ignore the VBE voltage transistor Q1 and mensubsitusi formula, obtained by mathematical relationships

In the circuit of regulator Op-Amp of this output voltage can be adjusted with the set of R1 and R2.