This is my original blog – all of the material in here has been moved to the now very popular – you can find all the older material, some of it updated – and a whole load of new stuff – at

8-pin chipOne of the guys who looks in here re-blogged something of mine and I thought I’d take a look at his site – and discovered these:

The PR26MF22NSZ and it’s larger cousin the PR39MF22NSZ  are miniature 8-pin devices which look for all the world like any other 8-pin chip – but are able to switch mains power at up to 0.9amps – i.e. up to 200w. Seems unbelievable but that’s the claim – sensible you could certainly run a typical mains light.

Given the very small size of our ESP-01 boards and the equally small size of the mains power supplies I found earlier, these would appear to be an ideal companion. Right now they are marginally more expensive than the cheapest Chinese relays and even very slightly more expensive than some solid state relays – but the size has to make it all worthwhile?

Digikey have the larger one at 1.18 but the postage kills that option – you have to wonder what their marketing people are thinking about – 1.18 for the chip – 12.00 for postage – come on guys – it’ll fit in an envelope!!!

The best I’ve seen up to now is £1.97 with free postage here..

I’ve ordered one just to see what size it is – I’m hoping this surface mount version is the same size as the normal DIP… time will tell. If it is at works I could see a board coming on! Here is some more info and a diagram.


  1. If your circuit is isolated (i.e. no live parts can be touched) then why not consider a transformerless (capacitive) psu?
    This also lets you drive scrs or triacs so no need for solid state relays.

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