LED Night Sensor Widget Assembly Notes. Toby Robb 2013 This board can be fed from either AC or DC 7-35 Volts. 7-9 volts DC is ideal as it generates less heat in the regulator. With heatsinking the regulator can probably safely deliver up to 750mA. The output at the terminals is 5 Volts. Calculate your LED load resistor accordingly. With a 3 Watt led everything runs quite hot especially the load resistor, the regulator and the LED itself. So care must be taken when siting the board to avoid anything catching fire. You have been warned! A 1 Watt led is ideal for this board. There are a couple of mistakes in the board at the moment. The 2 Power capacitors are marked incorrectly on the board. They need to swap positions. The larger electrolytic should be on the DC regulated side. The LDR fixed resistor should be a solid link. Choose your load resistor to suit your LED. Keep the current below 750mA, or even lower if you can. The values printed on the board for the brightness and delay potentiometers are marked incorrectly on the board. They need to swap positions. Note: The jumper will probably not cut the power if your using AC in. If you are using DC the screw on the left should be positive and the jumper will work. Known bugs: If you face the light back to into the LDR you may get oscillations. The light will switch on and off a few times as it aproaches darkness. This needs a proper fix in software.