Fake 30A Car Audio Voltage Converter
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- čas přidán 21. 08. 2024
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Sold as a 12V DC 30A buck regulator, this cheap power supply doesn't come close.
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As already mentioned, maybe the 888-5A on the PCB was the clue. 😉
I was just about to write it :)
it was
It we be interesting to see this rigged up to a 30A test load and see when the magic smoke escapes!
Try it, try it, try it, try it....
Then complain to the seller that it's not up to spec. Don't let them get away with the scam.
I was about to say the same - the only thing missing was the 30A smoke test :-)
It wouldn't blow up violently, those integrated switchers are pretty well protected, probably only the diode would short out.
It even is printed on the PCB 888-5A
it's like PMPO on jubilee audio stuff: thermal power output during spontaneous combustion.
Come on its just a honest mistake the decimal point fell off during production governor. ;-)
Chinese specifications are almost always aspirational at best.
The magic is that the 30A power is stored in the heat sink,
and it works whole 5s!
In the lower-right corner it says 888-5A which maybe means 5 Amps.
remember, in china, its ok to just add up the amps of different output voltages...
Fake stepdown is best! If it fails everything behind it goes boom!
It might not be only CCA. I have multiple cheap ATX PSUs that seem to have significant iron content in their wires. Try a magnet!
I think the "888-5A" on the board might be a clue. :)
The smaller regulator makes sense, it's only supposed to help down-regulate alternator voltage (14-15v) to 12 with very little current to trigger other devices, basically logic level current. With that the small caps, wires, traces are all just fine. The inductor and 5.5A JRC (NJR/Japan radio) regulator is just laughable though for a supposedly 30A device. Vehicle fire waiting to happen?
Wow, a smoke machine for about 10$? seems like a steal to me :D
I believe you got this completely wrong! it is 30 Amp hours TOTAL: run it at 30, blows instantly, run it at 3 amps, blows in 10 hours.
XD
but that's like 300mA for 100 hours!
@@SimonQuigley i bet there's a rule of diminishing returns with lower currents... the time gain gets asymptotically shorter
An LM7812a voltage regulator is rated 1 Amp output at 12 volts,
but with minimum 14.8 Volt input voltage and an excellent heat
sink, the _typical_ maximum current out spec is only *2.2 Amps.*
Just wondering if the advertised 30 amps was car audio peek as seen with some base beats.
My thoughts are that the device is to be used on 24V trucks to power a 12V (cheap) car radio. I have a friend that have similar (but legit, beefier) units like this to power some 12V car devices on his truck. Like a 12V radio, a small TV, a car fridge, few GPS, some chargers and so on.
This unit have two regulators. The small one is to be used as main power for the car radio: the yellow wire (constant, batt, memory or whatever is marked), that is to keep the settings and power the main board. The power needed is small so a 7812 makes sense to be used.
The second power supply is to be used to power the real audio power amp and that is the DC/DC converter. My guess is that the marking 888-5A is the actual current output rating, that is 5A max. So 60W max. That makes sense for a regular car auto at the red wire (ignition, key or whatever is marked) that is powering the main power amplifier (2x30W or 4x15W).
The joys of eBay :)
I would like to see a build of a 12v dc-dc converter
Your a smart guy. The switching regulator looks easy to make it any current you need. It has npn output, add a couple transistors and beef up the coil and diode.
It's got to be worth a fiver for the aluminium case alone 🤔
The ACC is usually less than 0.1A, if even that. It's mostly just a signal. The other things are a problem. 😂
Can't believe you didn't try to run 30A through it. Big clive or photonic induction would have ran it until it popped!
You can’t. It will fail well before that load.
@@ernstoud that's the point...
@@ssj4jamie592 Photonic induction?
@@leepshin czcams.com/users/Photonvids
"I've popped it!"
@@ssj4jamie592 OH nice one Jamie 👍. Channel looks awesome. Cheers bud. 🍻
I bought a couple of these, needed 12v on a 24v forklift to run the fan in a cab heater we added. The first one didn't work (probably blew immediately on powerup) and the second one lasted a very short time with a load of about 10a for the fan. The diode blew. Bought a much nicer potted unit ($$) which worked fine. The Chinese are notorious for misplacing the decimal point on several things I have purchased!
this sounds like the kind of mistake a low paid, unskilled person would make at the factory, not reading a decimal point. also common is, they dont know the difference between mm and cm (small measuring error of 1-2 cm) its usually clear they meant mm.
She's a rough PCB design that one!
This converter works with a duty cycle of about 50%, so a 3A diode is sufficient for a 5A output.
give it 30A and show us how it glows red hot! We love smoke to!
Nice video
The case doesn't look too bad. 😆👍
at least a nice serviceable module case!
Love the heavy trace spacing
board says 5 Amp is that what the output load is?? and the 30 amp is a chinese lie??
You might as well use one of your many rechargeable 240v inverters to power the HP PSUs directly, if the power is renewable, and work out how to keep "the powerbank topped up" instead.
Thanks for showing the lighter trick. I didn’t know that. You can always tell the power output by the size. 12Vx30A = 360W … never. I use the one similar to the first one you showed, but manufactured by BTF Lighting which is a half decent quality brand. They don’t tend to inflate the output current rating! Lol the inside of that second supply was embarrassing!
Size _alone_ doesn't give it away. An advanced supply in that size could easily output 30 amps. Don't believe me? Just look at computer Vcore regulators.
Now the size _combined_ with the low price, yes there's no way.
@@eDoc2020 yep undoubtedly correct!
I think you get it wrong about that car voltage converter. According to the circuit drawing, it clearly says the power source is meant to be a 24V car battery. So this thing is just a stepdown converter and can deliver up to 30A. So it is mainly for Trucks that have a 24V onboard voltage, instead a 12V onboard voltage of a car. But most car radios and audio systems need a 12V supply.
And a car battery can easily deliver enough Amps for the max. output of the Converter. But it would be interesting what will happen if you draw more than the rated 30A 🤔. Maybe that converter transforms into a beautiful heater or electric grill for some sausages or beacon 😂.
Did you mean sausages or "bacon" ?, with 30 Amps it'll surely light up like a beacon.😏
@@brucepickess8097 Yeah, bacon, of course. My bad.
power it up and blow it up!
That was 10 years old, from the date on the pcb. Buy up a load of junk for next to nothing, sell it quick and disappear even quicker. Normal business practice for your online seller.
Well... you've got a nice project housing, if nothing else. 🤷♂️
Since car audio headunits don't generally consume a continuous draw, those little caps and regulators can probably supply near the 30A load for milliseconds (duration of a low power bass hit), making it "30A max"... sellers of cheap crap love to try and play with technicalities in their marketing. Hell it may actually be "fine" for a headunit without a cd player as the continuous draw may be well less than 2A.
Isn't that the whole point of PMPO? :-)
Rather like some cheap inverters where the stated capacity is peak, rather than rated.... if you're very lucky!
The ACC is the contact of the car, and the other wire is probably a 12v high Switch (yes acc is accessories) meaning your car appliances are powered on
The high switch is a 12v + signal into an amplifier telling it to turn on
The acc is obviously from the car ignition module
I think its a little useless however you could use the acc on a light or whatever to switch on the converter and Amp Instead of pulling a wire from your contact in the dashboard
the 30a max stands for maximum 30a power draw from the input when the 12v out is shorted to ground , but if its capable of 5a this is good enough for cheap car radios that don't consume much more than 5-10a before distorting but i hope the output is at 14.5v and not 12v , that will kill some watts of the cheap headunit.
Ebay should have a way of reporting dangerous and fake items.
Go on, put 30A through it. Let's have a laugh. :)
I hope you left feedback on the item and reported it as fraudulent. So many sellers selling fake crap on eBay. Although, as the saying goes... If it's to good to be true, it probably is.
I had similar converter(not sure about components tho, but it was one of those cheap versions) . Weirdly 10A was not a problem for it. It was a bit toasty but worked. Of course I would not use it for any important things but for some weird projects or test... Why not.
Thank you for sharing
So at a maximum of 3A you would need at least 10 of them to get the 30A output needed...kind of making the £7 cost (totaling £70) not a very good deal against the £20 for 25A.
I had exactly the same thing, bought one too run my 12v diesel heater off my 27v solar garage setup. Thought this is "VERY" light lets have a look, yep that will handle 20A NOT.
The surprising moment, for me, was the whole copper-coated aluminum wires... WTF? Really, how much money can that save the supplier?
A diode in a cheap buck converter only conducts part time when the mosfet is turned off. Assuming a 50% duty cycle, would that mean the diode could conduct 6 amps momentarily?
In a switching application the time to recovery is the problem. It's the time the diode conducts in reverse, at full voltage, before it halts the current that really causes it to fail.
looks like it's for hooking up a 12v car radio/cd to a 24v truck system ( hence the acc passthrough from the ignition )
3A should be more than enough in that case, no??
Did you get this from Del Boy at the Market?
i got a 48 to 12v 25A
Surely you have a case to get your money back on this?
MC33167 Regulator equivalent.
Not the first time they forgot decimal points.. 😂
put 30 amps through it and capture the magic smoke on camera! :D
That's just proof that they like adding zeros to stuff to make it sell 🤣🤣🤣
Classic case of China missing the decimal point out totally in the label printing LOL the 5A on PCB gave the game away once you took the lid off.
Non branding of components especially hi current ones tells you a lot though there's the fake screen printing of course
If you swap the diode will it handle the current
I've seen evidence in other videos that suggest that those converters are not entirely potted. The creator had a failure, cap blew straight through, and they were able to easily remove the chared board remains. Not rich enough to chop mine open, but food for thought lol
It reminded me about one situation when I had some case potted and when I tried to open it it turn out that inside was another thin aluminium case and they just potted top of it so it was like maybe 3-5mm thin layer... -_-
@@paranoiia8 Chinese ingenuity truly knows no bounds.
i don't even think a switcher built that dinky could push 30 amps, much less a linear lmao
OMG - this part will burn at 5 A already! I am afraid a real 30A Buck converter can't be cheap! Should probably be around 30 Eur i guess (1 Eur/A)
Maybe it was 30amp… at 1volt 😂
Oho so sade
…at least not a bad deal for a decent aluminium case… 🤣
Cheap 30A converter turns into an expensive 3A converter.
Nice metal project box! Just about.
Wow 10 year old revision date.
Even says 5A on the PCB silk screen, haha, what a joke.
You get what you pay for, You can go far too cheap
me i would get a 200A (2200W) Caravan DC DC 24V 12V Converter one that rated for 12V Fridge Loads
You get what you pay for.
This, as it stands and for its' application, isn't fit for its' purpose and is dangerous! They couldn't even design the simple 7812 right - it needs small (0.33/0.1uF) low ESR caps as near to the leads as possible, or else it can oscillate. However, I like the case and you could properly build say, a 24VDC to 19VDC converter for a laptop or something like that. Wow, so much of this stuff is dangerous rubbish!
In these things a friend of mine once told me (and me with a flashlight geek being) he told me to remove atleast one 0 and me I told him to remove atleast 3x0 when you have a Chinese flashlight (yes its totally dependent on source) I'm talking about the military ones, where I even spoke to a dude who was convinced that his military light was more powerful than my 10K lumens torch
Is the Diode used in circuit or is it just reverse polarity protection? Either way, this cheap piece of **** would be lucky to give you 5A peak......
Can't trust anyone these days
It's the freewheeling diode of the buck converter. It is required (and not for protection).
Those are chinese amps, divide by 10 to get metric.
I picked up one of those cheap converters a few years ago, they were complete rubbish.
Yeah they always lie when it comes to the amps , and also the efficiency.! and they aren't reliable in continuous service at high current, without active cooling .
in DC battery systems , DC DC converters must be avoided. otherwise just use a dc to ac system and accept the efficiency loss
“Looks a bit cheap.” That is because it is! Garbage.