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 that the trusty 555 timer was tricky to ...

We’re extremely fortunate then to live in an age in which a cheap, lightweight, and efficient solid ... a relay can be wired as a buzzer, and it’s this property that a vibrating reed inverter ...