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. […]

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 […]