I just pulled apart an IKEA night light to see how they are doing what they do. I don't think it is sold any more.
If you follow the link it's a little cylinder with a rotating dome, two blades in the back plug right into a wall socket. There is a light sensor window, when it's dark the LED comes on. I had to pull one apart to see how they ran a LED off the AC line. It's a pretty conventional capacitive divider driving a zener, and I wouldn't discuss those details here.
What I found interesting was the sensor/LED driver: they use what looks like a CDS photo resistor driving a... 555! Looks like they just make a resistor divider to the threshold input, drive the LED from the output pin 3 thru a resistor.
Thought it was fun to find a 555 inside there.
If you follow the link it's a little cylinder with a rotating dome, two blades in the back plug right into a wall socket. There is a light sensor window, when it's dark the LED comes on. I had to pull one apart to see how they ran a LED off the AC line. It's a pretty conventional capacitive divider driving a zener, and I wouldn't discuss those details here.
What I found interesting was the sensor/LED driver: they use what looks like a CDS photo resistor driving a... 555! Looks like they just make a resistor divider to the threshold input, drive the LED from the output pin 3 thru a resistor.
Thought it was fun to find a 555 inside there.