Hi All
I’m looking to embed a mains PSU into my project, but I can’t find any which aren’t £15+. I’m basically looking for the guts of a £3 phone charger, but not in the phone charger package. Don’t know if I’m searching for the wrong thing, but I can’t for the life of me find one!
Anyone got any experience in this area?
Break open a phone charger package and use the guts? I suppose you’ve already done that. In the least, try doing that just for proof of concept to make sure it works.
I’ve used the guts of a basic 6VDC wall-wart transformer. It’s bigger than a phone charger though. Perhaps the phone charger won’t have enough power (amps) to run your project, which is why you need to try it first.
Managed to destroy two phone chargers this way! They should have enough power. I understand most are able to conform to USB spec (500mA, 5v => 2.5W) which is plenty for what I want. Might have to buy a few cheap chargers on eBay and be a bit more careful…
I posted some links to Digikey in a thread that chorus started about a coffeemaker project a few days ago…
http://forums.electricimp.com/discussion/1599/powering-imp-using-vin-red-blinking-light-#Item_19
With this one, they (a user comment) say the output power is 1Amp.
I’m sort of doubting that … without seeing a data spec sheet to prove it. If you’re powering just the imp and a few misc components, it will probably work good. But if you start adding coil relays, lights, extended wire runs, then it might be an issue.
It could be something that might break apart easily to use the “guts”.
I looked into this a while ago if you need to bite the bullet. These two are about £8 quid each the power pax needs separate connector
http://uk.farnell.com/myrra/47122/power-supply-2-75w-5vdc/dp/1825773
That one from farnell looks great, thanks!
@opb forgot to say I use these Adafruit perma boards for all my imps there top notch
http://proto-pic.co.uk/adafruit-perma-proto-quarter-sized-breadboard-pcb-3-pack/
Returning to the subject of AC, are there any potential issues incorporating this into a project? I recall Hugo saying in another thread about one of the reference designs not being published due to AC isolation issues with the IMP001 module. This isn’t something I know a lot about, but I’d like to follow best practice when it comes to putting my projects together.
If anyone had any advice/resources for incorporating AC into a project, they’d be very much appreciated!
I’m working on the same thing. There are a number of converters out there, but many of them need additional parts to make the power clean and stable. I just asked Hugo to comment on one that I found that I believe just needs a fuse on the A/C side. It is in the thread “On the death of an Imp”. I’m waiting to see what he thinks about that one. It is $23, but if he thinks it is solid, I’ll probably use it, and probably try to build an AC switch around it.
@opb the issue is just isolation; the becky project had a non-isolated supply (well, it was an isolated supply that we then tied to neutral) because it had to sample AC voltage as part of the power measurement.
This would be fine with an imp002, so no metal was exposed (ie, seal everything within the case), but with an imp001 this is not such a good idea (because you could take the card out and stick a fork in the hole, and get neutral - or live, if your socket was miswired - out of the cutlery).
Besides the isolation, there weren’t issues with becky - I have one of the 3 units I hand-built in my house and it’s in daily use 
Thanks for the replies guys! I wasn’t sure if ‘isolation’ was some technical term, but I totally understand the idea of isolation from the outside world. My IMP001 is sealed inside the project box, so I reckon that should be OK!