Another Junk Box Solar LED Candle
Solar powered novelty items such as an electronic candle have become very inexpensive and common place. Looking from the outside, it consists of a small solar panel to harvest power from daylight and some sort […]
Water Activated LED Marker
The water activated LED marker is a great scuba diving or night diving accessory. Its bright marker light turns on when its sensor probes come into contact with water and turns off when the probes […]
NE555 0-10S Delay Timer Relay Module
Sometimes you may need ready-made hardware to set up a simple timer to help you control something at the right time. No wonder, Chinese electronics have many instant solutions for that, the simplest of which […]
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, […]
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 […]