For op-amps circuits the power supply must provide positive and negative voltages. Here is a simple bipolar power supply unit which is able to provide ±1.2V to ±22V.
The bipolar power supply unit is based on LM317K and LM337K regulators. LM317K and LM337K are linear voltage regulators for positive and negative voltage, respectively. They are available in TO-220 packages and both of them incorporate various protection circuits such as current limit (which limits package power dissipation to about 15W) and thermal shutdown.
Positive and negative voltages are independently adjustable from VR1 and VR2, respectively. Each regulator is able to provide up to 1A when being properly mounted on a heatsink. Capacitors C5 and C6 are used to improve ripple voltage rejection.