I bought one of these cheap power supplies from Poundland purely to take to bits, thinking it was going to be a hideous electrical deathtrap. I was pleasantly surprised to see that the internal build quality actually seemed to be quite good. There was modest filtering, good electrical separation, proper opto-isolated feedback and the transformer had a heavily insulated secondary winding. The only thing that is a bit odd is the choice of 5.5V for the output. Off load it actually measured about 5.7V and it withstood a couple of short circuits as I probed the awkward connector.
Given how many of the cheap ebay USB power supplies from China are potential deathtraps, it was quite nice to see one that made an effort to be compliant with safety standards.
Given how many of the cheap ebay USB power supplies from China are potential deathtraps, it was quite nice to see one that made an effort to be compliant with safety standards.
Not gonna lie, I was hoping you would just for gits and shiggles.
If it's still tucked away somewhere in a distant drawer would you consider sending it to Electroboom with a note suggesting it's some kind of free energy device…
I was just waiting for him to blow it up with some power.
Aww I thought he was going to plug it in
im not sure if a split bobin is a good idea. it seems the coupling wouldn't be good enough for flyback converter.
Usb chargers output 5-6v to account for cable voltage drop and primary side regulation
Admit it. You were dissapointed ; 🙂
Managed to get one of the newer ones (signlex, came out within the last week or so), rated at 5V 1A… am guessing it has a similar layout… bonus, i got mine for 90p as there was a sale on for some reason.
I just wondered if it was possible to write an operating system in HTML…
Sometimes items of surprisingly good quality show up at dollar stores here in the U. S. and it's not clear how or why. I've noticed that £1 stores, at least judging from YouTube videos, get better things: a pound is about 1.5 U. S. dollars and that seems enough extra value to ensure a distinctly better class of products. I don't think I've even seen a USB power supply at Dollar Tree (probably the biggest U. S. chain), apart from the ones for car cigarette-lighter sockets.
I bought a cheap, black USB charger (note… this is a parody of Clive's "cheap pink USB charger")
from Poundland
I plugged it into my brand new iPad
and it wasn't bad…
Due to the tiny wires in the usb cable, the 5.5 volts arrive as about 5.2 volts or less.
There's probably a zener diode that clamps the voltage down to 5.6v or less – the regulation is lousy on such power supplies, they have to output higher because when you actually put a load, the voltage will go down slightly.
They also use a higher voltage because the cables are usually very thin and there's quite a voltage drop on the cables at various loads.
Great video what was the output (ma) of the charger?