Next time your at a LED traffic light, realize that they are so many leds there isn't a need for a resistor so they only have rectifiers and you can see the LEDs flashing at 60Hz so yes they have ...

110V AC outlet (100W max) 5 LED battery level indicator lights Overcharge, short circuit and current surge protection Air vents + cooling fan 2.7 x 2.7 x 6.1-inches, weighs 17.8 ounces ...

Its NO contact closes and passes 230V/110V AC connected to J1 to J2. The gadget connected to J2 turns ON. When you push PB again, the second pulse is generated and counted by U1. It’s Q1 (LSB of ...