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 ...

Here is a great collection of touch switch circuits. A touch switch is an electronic device that enables us to control a circuit by simply touching a sensor. Simple touch switch circuit with 4011 – ...

Last week I explained how to use a motion sensor to trigger an event with an Arduino. The event we triggered was a simple blinking of an LED. You can do a lot with a bunch of LEDs if you use your ...

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 ...

An RC circuit in series with the coil allows full-current turn-on for reliable relay operation, then reduces the current to save power. Fellow engineer Sanjay R. Chendvankar of Mumbai, India, recently ...