T.K. Hareendran is an Internationally certified Professional Freelance Technical Author and Circuit Designer with more than 25 years of experience in the domain. Now he is actively engaged in the expansion of «TechNode», an advanced, independent electronics R&D lab founded & promoted by him.
T.K. Hareendran
T.K. Hareendran
Areas of interest of the author: Relay Audio History of Electronics High Voltage Beginners Supply Measurement Microcontrollers Usage Automation Analogue Design Oscillators Tools and Technologies Robots Power Security Light Solar
Publications on RadioLocman by the author T.K. Hareendran:
- Hybrid relay basics: Why engineers are switching smarterHybrid relays are changing the way we think about switching inside electronic circuits....Oct 6, 2025
- Revisiting µPC1237, a classic audio amplifierThis is just an ultra-quick blog post about a nostalgic IC: µPC1237. It’s a timeless...Sep 23, 2025
- Hands-on with hobby-grade arc generator modulesArc generator modules may be small in scale, but they offer big opportunities for hands-on...Sep 9, 2025
- Build automatic transfer switch (ATS) with simple analog electronicsIn today’s world, both households and industrial facilities are exploring ways to improve...Sep 8, 2025
- A practical design guide for lightning detectorsLightning is one of nature’s most intense and unpredictable forces, but thankfully, we have...Aug 4, 2025
- How hot swap circuits and controllers workMost mission-critical systems need to be designed for near-zero downtime throughout their useful...Jun 3, 2025
- Ultrasonic mist maker (DIY)I needed a simple mist maker/humidifier for a project that I was working on. I found lots of...Dec 24, 2024
- Handheld electric PCB drill speed controllerThis handheld electric PCB drill speed controller is cheap, easy to build, and only uses a few...Sep 28, 2023
- Portable Power Inverter CircuitRecently, my neighbor expressed a deep interest in building a low-power inverter from scratch. This...Jul 19, 2021
- Use Inexpensive Components To Create An Infrared Close-Object Alert CircuitMany robotic applications require a sensor to detect close or very close obstacles. Typically,...Dec 10, 2018
- Smart Power Supply for Microcontroller ProjectsA good, reliable and easy to use dc power supply is probably the most important thing for every...Feb 19, 2017
- Low-Cost Impact Sensor Uses Piezoelectric DeviceAlthough piezoelectric elements have been used for shock and vibration detection for some time,...Feb 2, 2014
- Outdoor Garden Solar LightsThis Outdoor LED Solar Garden Lights project is a hobby circuit of an automatic garden light using...Oct 12, 2010