Poor man’s Luxury Car Dome Light
If you often drive early in the morning or at night, you spend most of your time in a dark vehicle, and at that time a small interior/dome/cabin light becomes an indispensable widget if you […]
Dual PC817 Optocoupler Module – Buy or Do It Yourself?
A while back, I came across a set of multichannel optocoupler modules at a discount sale, and what immediately caught my attention was the PC817 dual-channel optocoupler module in that collection. So, this post is […]
An Eternal LED Scarecrow
Recently, I wanted to try an electronic scarecrow in my lab window to scare off some birds (often nocturnal) that make a lot of noise and dirt. Although there are many options for building one, […]
Dual MOSFET Switch Module – WORTH IT OR NOT?
What is the point in critiquing a cheap Chinese power MOSFET module, you might ask. But I have a reason for that, because learning something useful from other people’s mistakes (even if they are trivial) […]
Learn To Play with Ceramic Resonators
As Wikipedia says, a ceramic resonator is an electronic component consisting of a piece of a piezoelectric ceramic material with two or three metal electrodes attached. Like the similar quartz crystal, when connected in an […]
Self-Lock Delay Switch Module DIY
Self-lock delay switch is a simple timer module that produces a fixed square pulse. It is designed around the 555 timer and uses a tricky negative edge trigger to ‘run and lock’ the timer. The […]
Build Your Own Bicolor LED Waistband
Inspired by a dazzling Chinese design, I started thinking about making my own bicolor LED waistband with a few components lying around my workbench. In this post, you can see the basic design concept of […]
Tricolor LED Signal Baton
An LED signal baton (also called marshalling torch) is a proven gadget to head traffic. Primarily it is widely used by traffic police, attendants etc. to channelize traffic but it is a great handy aid […]
Multipurpose Power-Thrifty LED Flasher
Sometimes you may need to make a battery-operated lamp flasher suitable for a variety of applications. In this post you will see the design concept of a 555 timer based multipurpose LED flasher that requires […]
Universal Pulse Extender Module
On certain occasions it is necessary to use a sensor module that generates a relatively short pulse to indicate a change of status. If the duration of its output signal is too short, the associated […]