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 […]
Arduino VCLED Flasher – Another Fun Project for STEM Kids
As promised, here is another fun electronics project for our STEM kids. This time the theme is the setup of an Arduino VCLED Flasher. So, get ready to see a simple voltage controlled lamp flasher […]
Current Mirror Segments – Part 1
A current mirror is a circuit segment that functions to produce a copy of the current flowing into or out of an input terminal by replicating the current in an output terminal. In the analog […]
Automotive SSR Module v1
After getting a few vintage automotive solid state relays (SSRs) from a flea market thru a friend abroad, I decided to make a low-cost automotive solid state relay myself. So, this post covers the design […]
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 […]
Handy Test Light (v1)
Get ready to make a high-resistance continuity tester pen that runs on a pair of common 1.5V AA batteries. This design is based on an idea from a Chinese website but with a few modifications. […]
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 […]
CD4541 Programmable Timer IC Cheat Sheet
Today we are going to inspect the CD4541B CMOS programmable timer IC. The CD4541B programmable timer chip has a 16-stage binary counter, an integrated oscillator for use with an external capacitor and two resistors, output […]
An Old School Transistor Shunt Regulator
I had some time to kill on a recent rainy monsoon night, so I decided to brush up on my knowledge of basic shunt regulators. Luckily, I had a lot of BJTs and Zener diodes […]
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 […]