Photosensitive Bristlebot – STEM Edition
Bristlebot is a great easy way for kids to start to learn basic electronics. Bristlebot is perhaps the simplest form of a walking robot with a rigid bristle toothbrush body. It seems simple, a Bristlebot […]
Another 555 Timer IC Electronic Latch Switch
You may not know the name of one of the first independent semiconductor designers, but you have encountered Hans Camenzind’s designs countless times. Incredibly, he created the 555 timer chip alone, spending a year designing […]
Mercury Tilt Switch Fun
As you know, a mercury switch can be used to detect any inclination with respect to gravity. For example, suppose your home security alarm wants to know when someone opens the lid of your cash […]
Automatic USB Mains Switch (v1)
Recently I wanted to build a USB controlled power strip that powers some peripherals as soon as my computer starts up. Luckily, I managed to find a commercial USB-Power On switch in my attic (see […]
6V Battery Guard Relay Module
Many of the newer robotic toys for kids now use 1.5V AA or AAA batteries as the power source. And it is a common practice to wire them in series to get a healthy 6VDC […]
5V Microcontroller Power Rail Guard
This 5V microcontroller power rail guard is a quite simple solution to add an overvoltage protection (OVP) mechanism between the 5VDC power source and your microcontroller board. In short, this little design uses a Zener […]
Doorbell Sensor IoT Module (v1)
In this post, I will attempt to share the design idea of a doorbell sensor that can be build using just a handful of inexpensive and easily available electronics components. When cleverly integrated into your […]
Poor man’s AC230V Smart Plug v1
Recently I have received a few messages from a follower who is interested in making a simple relay box that will help him operate some regular electrical devices using the control signal from a common […]
Lazy LED Flasher – Learner’s Edition
Every once in a while, I have found myself needing a quick circuit to blink a light emitting diode. It is quite easy to build simple microcontroller circuits which performs this task thru a few […]
KA431/TL431 Time Delay Switch
The real inspiration for this post actually came from lots of lame designs seen on the web. The last drop was a reasonably great written article presenting a number of blueprints to build timer circuits […]