Multiple Voltage (+_-12V and +_-5V) Power Supply

Figure 1.  Circuit Diagram for a +/-12V / +/-5V Power Supply

This is a power supply circuit that provides +12V, -12V, +5V, and -5V regulated outputs.  This is just a more complex derivative of a basic negative/positive voltage supply.

Two separate sets of transformer and diode bridge are used to generate the +/-12V and the +/-5V, but the rectification circuits are almost identical.  The only difference is the voltage regulator IC's used.  The 7812 and 7912 are used to regulate the +12V and -12V outputs, respectively.  The 7805 and 7905, on the other hand, are used to regulate the +5V and -5V outputs, respectively.  Note that these voltage regulator IC's need to be attached to adequate heat sinks if used in applications that require high power.