This power supply will give you about 100 mA of regulated power, add heat sinks and you will double that.
Given that the regulated power is a limited resource, wouldn't it be nice to cram some extra juice out of this power supply?
Notice at the bottom right corner, there are three pads called AUX, GND and LED.
This is the auxiliary DC power.
- It is unregulated at about 20-23 volts
- It will provide about 500 mA, depending on your transformer
- It is filtered, but not at the same degree as the regulated supply
You can use this for any additional devices that needs DC power. There is also space for a resistor, called LED.
For anything that needs DC power, connect AUX and GND (positive and negative connections).
Connect an LED
There is space for an on-board current limiting resistor for LEDs. Add a suitable resistor and connect your LED to the connections LED and GND.
(It is usually safe to assume that the forward voltage drop of your LED is 2 volts, and that the maximum forward current is 20 mA.)