Circuits & Schematics - Beginners - 2

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 ...

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 a negative power ...

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 ...

Use a transimpedance amplifier to drive an LED You can test an IR (infrared) link with a circuit that converts an IR-generated photocurrent to an amplified current that drives a standard LED (Figure 1). This approach provides a visual feedback to ...

The classic Colpitts oscillator circuit in Figure 1 generates a clock signal with a fixed duty cycle. By replacing CMOS inverter gate IC 1A with a voltage comparator (Figure 2), you can obtain a more versatile and more useful clock generator. You ...

Part 1 . Theory Circuit Setup The circuit setup for this experiment is quite simple. You need seven 330 Ω resistors in series with rows R1 through R7 to limit the current through the LEDs. Then the rows are driven by RB0 through RB6 pins of ...