Wiring Schematic Diagram

Volt regulators such as the LM78xx series sometimes need to provide a little bit more current then they actually can handle. If that is the case, this circuit can help out. A power transistor such as the TIP2955 or similar can be used.

The power transistor is used to boost the extra needed current above the maximum allowable current provided via the regulator. Current up to 1.5 A will flow through the regulator, anything above that makes the regulator conduct and adding the extra needed current to the output load. It is no problem stacking power transistors for even more current. Both regulator and power transistor must be mounted on an adequate heatsink.