PCB a Week 7: Mains log sensor

Mats continues his challenge of designing one PCB every week. In week 7 he designed a voltage and frequency logger for household mains power supply. The device is designed around the ATtiny45 microcontroller which records the frequency and voltage, and passes measurements through an onto-coupler to an isolated logging board. This week I’ll just finalize […]

Safe enclosures for solid state relays and mains current

Solid state relays can switch everyday mains-powered devices like lamps, but there’s danger inherent in working with household AC voltage. Victor wrote a tutorial on how to enclose the SSR in an old laptop power supply case. It’s simple to build, and it keeps you and your fingers safer than a bare board. For a […]