In a previous video I showed some images that AvE had been sent by someone who's power supply went on fire while they were out of their house. (The neighbours heard the smoke detector and intervened.)
This is a similar power supply I bought to test with a high load and check out the circuitry.
I may go a bit deeper and test isolation at a later date, although that may involve destroying the power supply. I couldn't say if this particular power supply is an identical one to the unit that went on fire, as it may be from the same factory or maybe just one of many clones.
My tests did show a weakness that may have caused the fire though. The good news is that it's easily addressed.
Note that I'd not rate the current limiting function as being usable as a proper constant current supply as it is too unstable. It's better regarded as being an upper safety limit.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
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This is a similar power supply I bought to test with a high load and check out the circuitry.
I may go a bit deeper and test isolation at a later date, although that may involve destroying the power supply. I couldn't say if this particular power supply is an identical one to the unit that went on fire, as it may be from the same factory or maybe just one of many clones.
My tests did show a weakness that may have caused the fire though. The good news is that it's easily addressed.
Note that I'd not rate the current limiting function as being usable as a proper constant current supply as it is too unstable. It's better regarded as being an upper safety limit.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
His caught on fire so I immediately ordered one…lol
Gotta love Bigclive..
the socket should have the ground contact all the way back… that would prevent this from being an issue.
anyone who expects 8a from these leads probably deserves it coming
Very interesting point about the insulated earth pin and something I had not realized or looked out for before, on a related point I recently bought a Chinese aquarium heater which came with a UK style square pin molded plug which looked strange because it was very small, but fitted the socket OK, however the plug did not have a fuse or facility to fit one. "UK plug" looks like a reason to buy on Ebay, but non compliant UK plug , probably not.
Another superbly informative video from Clive. I'm a retired professional electronic engineer, but I still learn something new from most of Clive's videos. I bought a similar, but not quite identical PSU from Amazon recently and was pleased to note that it doesn't have the same partially sleeved mains plug.
noone has them but there are also ceramic screwdrivers for adjustments, usually used for rf though
Thanks Clive, came to this a bit late. Have a Lavolta model of this PSU and happy to report the cables are Good. Mains plug full earth pin and output cables all soldered connections to the crocks and the end of the cable is solder tinned and clamped. Wire is very thick and difficult to bend. Had a fault where the protection diode across the output went S/C so had replace that.
Thank you. I think I have this power supply and will check on the leads and the mains cable. It is amazing how a device can be made so vulnerable by these leads and the supply cord – which I will check. I often use my own power leads.
Check all your power cords with a magnet.
At least it will find the really dangerous copper steel ones.
The aluminium ones should have higher resistance than the copper.
This is an idea for a product to sell, a line cord safety tester.
I see people talking about soldering the test leads.
I hope the mean the croc clip end.
It is not good to solder stranded wire in a screwed terminal. The solder compresses and the connection comes loose. Maybe some types of terminal blocks are ok but it is still not the best way. Just twist it and fold it over once or twice to fit the barrel. Then tighten the screw.
You can solder the wire in the barrel but the strands will suck up the solder and make a weak point where it bends.
They just copied the 2 sleeved pins for the ground. Just copy, don't think.
The use of copper coated aluminium is just misleading unless it is indicated on the jacket.
Are the test leads also copper aluminium? Even if they are not they look thin for 10 amps continuous use. The crimped croc clips always make bad connection.
I will always turn off the bench power bar when I go home to help prevent our planned extinction by the unmentioned.
I bought one a while ago for North America 115VAC and it blew up the 2 IRF840 MOSFETS and one of the 47 ohm resistors connected to its gate. Next failure ws the P75NF75 MOSFET. Must be a poor design in the power supply!
After the first failure, doing measurements with a voltmeter, I discovered the power cord had the Line and Neutral reversed. This put the fuse on the Neutral side!
You get what you pay for!
I once used the flame test to illustrate the difference in quality between cca and solid copper Ethernet cable
Wow, how the f😮ck are these shit quality leads allowed in the UK? Surely there must be rules regarding imports that don't meet our strict UK regs.
I saw JW (hello JW here) do a test on these crappy leads, it's appalling. If you caused a house fire due to these leads and it was proven the lead being used was the cause I wonder if your insurance would pay up.
Good vid Clive. .
What's the problem with Cu plated Al wires? As I recall, the big foofraw around here (years ago) about Al wiring failing and causing fires turned out to be using connectors designed for Cu… what have I missed by not paying attention for all those years?