Circuits & Schematics Beginners

If someone in your family has the habit of not completely closing a drawer or perhaps the food freezer’s door you’ll appreciate this design. It senses an ajar door and, if the situation isn’t corrected within 20 sec, sounds a ...

Sometimes, you may need to make a DC/DC converter with minor components that can handle small loads. In this article, we are going to make something like that. This DC/DC converter using transistor has only a few components and can handle small ...

Safety fuses or fusible links see wide use in modern electronic equipment to protect the load and the power supply especially batteries against short circuits and excessive load current. Fuses are inexpensive and simple, and a wide range of parts ...

This 8051 microcontroller-based control circuit adjusts the speed of a small permanent-magnet dc motor via photosensors (Figure 1). The circuit can find applications in light-tracking systems for adjusting tracking-motor speed depending on the ...

Jeremy S. Cook hackster.io In this project, I am showing you how to build a digital laser tachometer based on Arduino for around 10$. If you need to measure rotational speed, you can just buy it or do it yourself and learn something while building ...

Mirko Pavleski Arduino.cc A simple to build, but very sensitive electromagnetic field detector. This is a simple device capable of detecting very weak electromagnetic fields (Figure 1). The relative field intensity is displayed on the LCD display ...

Stephen Woodward EDN Despite the ever-growing choices among single-supply “Rail-to-Rail” op-amps, it will always remain true that the only way to design an output stage active all the way down to zero volts is for the design to include ...

Russ Williams EDN Figure 1. Display of R-L-C circuit. There is one analog graphic which remains impressive in spite of all the computer graphics programs available for screen savers and such (Figure 1). Known as quadrature art, the display can be ...

Vladimir Rentyuk, Zaporozhye, Ukraine A magnet waved past a Hall-effect sensor does the trick This circuit allows you to turn on your holiday bulbs with a wave of the magic wand. The strings flash in sequence. At the heart of the idea is the ...

The following automatic battery-charger design is created with a circuit that could qualify as the simplest window comparator ever built around a single transistor. It starts charging when the battery voltage drops beyond a preset value, and it ...