The Sonoff Mini-D (MINI-Dry) WiFi Smart Switch

Erm, what? This is a new Sonoff product in the MINI series – this time simply with DRY contacts instead of having one connection commoned to the incoming power. Back in the early days there was a 4-channel Sonoff controller (rather big) with isolated outputs but that has largely been forgotten (It’s still on the Sonoff website for sale) yet dry contacts still have their uses:

For example – controlling an older oil boiler – the original thermostat may just have a dry (isolated contact pair – ifrten a requirement of such boilers) – which knocks out most of today’s controllers – or you might want to control for example a lower or higher voltage output than the incoming supply.

Sonoff Mini DRY does all that and more – but take note of the very low current capability of this device: switching an output of 100-240v (why do Chinese manufacturers ignore that fact that there are countries – Britain in particular – which have up to 250v – that may change if the US president goes ahead with making it more difficult for US consumers to use Chinese products – who knows!) – anyway with that output voltage, current is limited to 0.1A MAX – very low for a product that isn’t actually THAT mini. It is bigger for example than the Sonoff ZBMini.

At lower voltages – 12/24v current goes up to 2A max – compared to other Sonoff products – why the contact ratings are so low. I asked and the response was “low-current motor applications” – but of course powering a contactor is another use.

Anyway, here it is, isolated NO/NC and common connectors as well as AC and DC inputs and a switch pair – see photos. The DRY is also MATTER-compatible.