In the attached circuit, a doubler is added to a typical power supply, AC transformer, full wave rectifier and filter. R2 models the load, and represents any circuit that operates on the positive voltage. The components C1, C2, D1 and D2 make a doubler for the generation of a low power negative rail. The negative rail is taken at the anode of D1. R1 represents a low power load for the negative voltage. This represents one way a typical power supply can be modified to generate a low power negative rail for full bipolar opamp operation.