One of the operational amplifier stabilized power supply circuits

 Integrated operational amplifier , referred to as operational amplifier, is a DC amplifier with high amplification and deep negative feedback, which can be used
to combine and operate signals. Operational amplifiers are widely used in automatic control and other systems.
    Since the operational amplifier makes numerous electronic components on an integrated circuit, the regulated power supply circuit composed of the integrated operational amplifier has a simple structure. The operational amplifier itself has the advantages of good component parameter symmetry and small temperature drift , so its performance is very good.     The circuit is shown in the figure. When the input voltage of this power supply is 10-20V, the output voltage is 9V, the current is 150mA, and the internal resistance is 0. 003fl. Voltage stability <0. 002%, with overload and short circuit protection functions.     It uses the field effect transistor VT as the adjustment tube, and the reference voltage is formed by the resistor Ri and the voltage regulator tube vs.