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 […]
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 […]
TTL & PWM Laser Drive – Revised Primer
This article shows basic circuit ideas for pulsing low power visible semiconductor lasers using inexpensive components which are fairly readily available. First of all, you need to know that this is a very belated sequel […]
BYO Muddy Water Detector
The goal of this little post is to share an idea to build your own robust mud water detector using readily available inexpensive electronics components. Although unintentional, the sensor component in this design concept is […]
LM358 Variable Threshold Solid State Switch
I think you’re all familiar with the various Chinese sensor modules based on the LM393 IC. That’s good, but at this point I’ll share the design idea of an LM358 IC based variable threshold solid […]
An Improved Analog Sensor Interface
A while back, I got an inquiry via email about building a simple electronics circuit to monitor the status of an analog sensor i.e., whether it is open or working properly. After a little discussion, […]
Midget USB LED Lamp – DIY
There is nothing amazing about looking at the design concept of a simple USB LED lamp, I know. But believe me, the midget USB LED lamp presented here has a little power reservoir in the […]
Automatic LED Night-Light Teardown
I bought a cheapo Chinese automatic LED nightlight a while ago. Working on this “automatic color changing night lamp” is pretty simple. A photoresistor (LDR) turns the LEDs on when it sees darkness and off […]
Mini PCB Drill Speed Controller v1
This post explains how to build a mini PCB drill speed controller using a handful of common components you may already have stocked in your home lab. First off, let me say that this idea […]