Hello Richard,
Following your lead, I ordered a triple USB outlet from Amazon;
I will redesign the power supply enclosure to house the triple
power supply and the extension cord.
120/240VAC 50/60Hz
Outlet 1 - 3A
Outlet 2 - 2,4A
Outlet 3 - 2.4A
Maximum with all three outlets active - 8A
According to reviews, no abnormal warming detected.
The price of the power supply is pretty acceptable; (CAN$18.99 - ÂŁ11.40)
The extension cord from Amazon CAN$12.70 - ÂŁ8.05 (pack of two)
is also inexpensive.
Since the power supply doesn’t have a Ground prong, the extension cord
can also be smaller. Links at the end of our emails.
The extension cord plug can then be replaced (or not) to meet the required
outlet. (or adaptors can be used)
In this case, the microscope would have a permanent “tail” attached,
but no internal wiring/soldering would be needed.
The reason I’m adopting your more elegant solution resides in the fact that
the power to the Pi and the motors (and the LED) can be plugged/unplugged
easily, allowing to exchange the AC Power enclosure unit to a Battery operated
Power enclosure, for field operation by the adventurer ones.
I’m still trying to find a suitable power pack, that would fit inside the enclosure
without major original modifications. I’m planning to make two indents in the
body of the stand, to “hinge” on any of the Power enclosures, to be “locked”
in the opposite side with one bolt.
Thank you for your attention.
I’ll keep you posted.
Best Regards,
Luis B.
| r.w.bowman
27 June |
No apologies necessary, it’s nice to see people making improvements
Power supplies with removable mains leads are definitely my favourite, because then you don’t end up with those nasty adapters (which are invariable on the spectrum from unreliable to unsafe, at least when they have a massive UK plug hanging off them). I have a couple of multi-USB power supplies, and really like them - that way, you have one power supply that can run both the motors and the Pi, just using two USB leads. In fact, you can get away with powering two microscopes off some of the more powerful ones!
This isn’t precisely the one I’ve got, but it shows what I mean:
amazon.co.uk
ORICO USB Charger 5-Port USB Plug Wall Charger (40W/8A) with Detachable UK Mains…
Charge 5 devices simultaneously with just one mains socketWith this Orico 5-port USB smart charger, you can provide 5 USB charging ports for multiple devices from just a single mains socket.Super-fast USB charging portsOffering up to an impressive…
ÂŁ18.49
I’m aware that some amount of caution is warranted with these things - the cheap ones can be a fire hazard and I’ve not tried this one so can’t vouch for it - but it would seem like a really nice solution: no exposed mains wiring, and exactly the right output for the microscope (and some spare power for peripherals if you want it).
I did look briefly for an encapsulated 5V power supply with an IEC connector like you suggest - but drew a blank. I guess those little transformers don’t need an earth, and so tend to use figure-of-eight cables instead, which are also pretty standard.
Using a US/Canadian multi-socket with a local plug on the end also looks like a really sensible solution, assuming you can get hold of those bits wherever it is you’re building the thing. As you say, I’d hope most people building a microscope are also capable of wiring a plug - though some of the people building microscopes might be quite young, and while they probably are capable of wiring a plug, I wouldn’t suggest they do so without a responsible person checking it first 
(Attachment Wall Charger Fast Adapter,QC 3.0 USB Fast Wall Charger 3 Ports Tablet iPad Phone Fast Charger Adapter Quick Charge 3.0 Travel.url is missing)
(Attachment Amazon Basics Indoor 2 Prong Extension Power Cord Strip - Flat Plug, 6 Foot, Pack of 2, White, Extension Cords - Amazon Canad.url is missing)