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 ...

Let’s say you want to blink an LED. You might grab an Arduino and run the Blink sketch, or you might lace up a few components to a 555. But you needn’t go so fancy! [The Design Graveyard] explains how ...

How many remote controls do you have in your home? Don’t you wish all these things were better integrated somehow, or that you could add remote control functionality to a random device? It’s a common ...

Relays usually are driven using optocouplers, which offer isolation between analog and digital grounds to ensure that switching currents in the relay coils do not affect the noise margin of the ...