Looking for a mains switch inthe dark is easier if the switchcontains a built-in neon or filamentminiature lamp. Adding a small indicatorto any mains switch is helpful. It iseven better if the ...

This is a simple flashing led circuit with 2 leds and 2 NPN transistors. It illustrates the behavior of transistors and capacitors and if you use an oscilloscope it will be very easy to determine what ...

These days, if you want to flash some LEDs, you’d probably grab a microcontroller. Maybe you’d go a little more old-school, and grab a 555. However, [Jacob] is even more hardcore than that, as ...