Dual Regulated Supply from Single Voltage 2014-05-28

Here is a circuit that can generate dual plus/minus regulated voltages from a single unregulated floating supply, such as from a wall-wort or a single-winding transformer supply with no center-tap. The trick is that the low drop-out regulators used can either sink or source current. Thus, for example, if the positive current drawn is more than the negative current, the bottom (negative) supply can sink the current difference to maintain regulation. A typical regulator can only...

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Here's a variation on the previous Dual Supply circuit that uses an LM317 to generate 10V and then a LT1118 to provide a virtual ground to supply ±5V.

The circuit depends upon the sink/source characteristic of the LT1118 to sink or source the ground current, depending upon the imbalance between the plus and minus currents.
The advantage of this circuit is that the plus and minus current can go to the 1.5A rating of the LM317 with a maximum imbalance between the plus and minus currents of...

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