➀ A DIY circuit using an LM358 op-amp and light-dependent resistor (LDR) automatically switches on lights at dusk and turns them off after 2–6 hours, reducing energy waste.

➁ The system employs a super capacitor for timing control, adjustable via potentiometers to set light sensitivity and shut-off duration, mimicking human presence for security.

➂ Includes PCB design guidelines, calibration steps, and operates independently without manual reset, ideal for unattended homes or outdoor lighting.

➀ A compact GSM-based spy device is introduced that can monitor conversations over long distances, even internationally.

➁ The device is designed to be easily concealed due to its small size and can transmit audio when a specific phone number is dialed.

➂ The project requires components such as an IndusBoard Coin, SIM800L GSM module, Li-Po battery, and microphone module, along with specific code to manage the device's functionality.

➀ An IR remote switch is a wireless device that uses infrared signals from a remote control to operate electrical appliances, commonly used in home automation.

➁ The system consists of an IR receiver module, a signal processing circuit, and a relay to control the connected load.

➂ A standard IR remote control can be used, and the circuit diagram and parts list are provided for building the IR remote switch.

➀ This article discusses a reference design for extending the life of coin cell batteries.

➁ It includes detailed explanations on how to optimize power consumption in small electronics devices.

➂ The design aims to help engineers and hobbyists create more efficient battery-powered projects.

➀ The article discusses the development of an automatic water level indicator and controller device that addresses the drawbacks of existing water level indicators and controllers. This device uses Arduino Uno and includes components like water level sensors, LEDs, and a relay.

➁ The circuit diagram and working principle of the device are explained, detailing how the pump operates based on the water level detected by the sensors.

➂ Instructions for testing the device and downloading the source code are provided, along with insights from the author about the project's potential applications.

➀ The article provides a step-by-step tutorial on building a function generator using the ICL8038 IC. This generator can produce square, sine, and triangular waveforms up to 100kHz.

➁ The core of the function generator consists of an oscillator that generates different waveforms, which are then shaped by wave-shaping circuits.

➂ The breadboard prototype demonstrates the functionality, with the sine waveform output captured on an oscilloscope.