LED Torchlight
Most commercial torchlights use three AA or AAA cells connected in series, which produces 4.5V to drive white LEDs using a current-limiting resistor. These...
Voltage Regulator as Audio Amplifier
LM338 voltage regulator can also be used as an audio amplifier. The output voltage can be controlled by varying the IC’s reference voltage (pin...
Minuscule LED Night Marker
The minuscule LED night marker presented here is an automatic light beacon that wakes up at night, or when there is not enough ambient...
Automatic Water Level Controller Circuit: Design and Operation
Here is a simple automatic water-level controller for overhead tanks that switches on/off the pump motor when water in the tank goes below/above the...
12V Battery Absorb and Float Charger
Most battery chargers stop charging the battery when it attains its maximum charging voltage set by the circuit. This 12V battery charger circuit charges...
5W Stereo Audio Amplifier
Here is how we can build a 5W stereo audio power amplifier based on TEA 2025 IC and two potentiometers for left and right...
PC-based Oscilloscope Using Arduino
Oscilloscopes are an essential tool for electronics hobbyists and professionals to verify that their designs would work as expected. PC based Oscilloscope score over...
Speed Control Of DC Motor Using Pulse-Width Modulation
Pulse-width modulation (PWM) or duty-cycle variation methods are commonly used in speed control of DC motors. The duty cycle is defined as the percentage...
Force-Operated Toy Organ
This toy organ for children uses a readily-available force-sensitive resistor (FSR) and an NE555 timer IC. Resistance of the FSR varies with the amount...
ESP32 (Non-Standard) GPS Receiver
Introduction
GNSS – GG-1802 ($5 a piece)
Sometimes things do not fall in place and we curse ourselves for taking the wrong turn or making the...
10-Watt Audio Amplifier Using LM1875
Here is a simple 10-watt audio amplifier using IC LM1875. The IC has five pins and can deliver a maximum of 18-watt output power...
Accidental Switch On And Switch Off Protection Using Delay
The accidental pressing of the on/off switch due to human error may cause the failure of the system it is connected to, or cause...
Low-Cost Ambient-Light-Controlled LED Night Lamp
This LED Night Lamp uses a 1.5W LED module operated on a 12V DC power supply. Here, an L14F1 phototransistor works as a sensor....
Solar Tracking System
Generally, solar panels are stationary and do not follow the movement of the sun. Here is a solar tracker system that tracks the sun’s...
Portable Emergency Light Using Power Bank
This portable emergency light is based on a DC-to-DC booster module and a power bank. The emergency light is designed to provide sufficient illumination...
Solar USB Bicycle Power Box
The circuit presented here can be used to drive USB-powered smart devices, including smartphones, while riding a bicycle. Smartphones suck battery power extremely fast,...
DC Motor Speed Controller
Here is a simple DC electric motor variable speed controller circuit that can be configured to control the sweep rate of automobiles’ windscreen wipers.
The...
Automatic Plants Watering System With Melody
Here is a circuit for automatic plants watering, which can be undertaken every morning without any human effort. A sensor is used to detect...