What is the point of reviewing a cheap timer module, especially if it is based on the ubiquitous 555 timer chip? Recently I got an ‘updated’ version of the common 555 timer relay module. This time it ...
This light activated relay circuit presented here uses the 555 timer IC and a light dependent resistor or LDR to form a light sensitive relay in an intruder alarm system or for switching on a lamp at ...
“You could’ve done that with a 555 timer.” But what if all you have on hand is an ESP8266? [TechColab] needed to control a solenoid valve with a short pulse via a solid-state relay (SSR) but found ...