/diy/ - Do It Yourself

[Anonymous No.1032838]

Can anyone here fluent with electronics please give me your input.
How's the quality of this board? It's a 5v 2A usb adapter. Is it safe to use a few for a project? I've tested and they don't suffer much much voltage drop up to 3.5A, but they do burn out after 10 minutes. Is it safe to run it at 2.5A with a heatsink attached to the IC?

Will upload more images so you can see it better.

My project is basically an 18650 charging station. I'm going to have 5 of these, each wired up to 3 tp4056 chargers, letting me charge 15 batteries at once. They run at ~0.85A 5v each. Every IC will have a heatsink and there will be 2 low rpm fans to keep everything cool and quiet.

If it's rated for 2A and voltage doesn't sag, it'll be fine with a heatsink at 2.5A?

I want to build something that will last.

[Anonymous No.1032840]

[Anonymous No.1032841]

[Anonymous No.1032842]

Thanks in advance

[Anonymous No.1032845]

Also one final thing. This is my first time wiring anything for AC. Does it matter which wire gets connected to the board or does AC not have a positive and negative connection like DC?

[Anonymous No.1032847]

>>1032838

They MIGHT be okay at 2.5A. That's honestly the best anyone can give you.

...well, it's not, but I sure as fuck am not going to reverse-engineer the whole thing and guess at part specs to figure it out. My advise is to ditch the USB supplies and grab a discarded PC power supply. Most still have plenty of grunt on the 5V rail; certainly more than enough to handle the 12.5A you'd be asking of it.

[Anonymous No.1032849]

>>1032845
>or does AC not have a positive and negative connection

This. You look to be Aussie or NZ so google MEN system (Multiple Earthed Neutral) and read up.

If they can supply over their rated current and don't go into over current shut down mode I'd rate them as cheap junk.

[Anonymous No.1032851]

>>1032838
If it doesn't supply enough current, why not just add a 6th or 7th usb adapter? Also, the xformer is likely the limiting factor rather than the chips.

In general, I'd agree with this >>1032847 anon. Old PC power supplies typically provide plenty of power on the 5v rail, so you would only need one of them.

[Anonymous No.1032852]

>>1032851
>>1032847
Old PC power supplies may, but they're a lot more bulky and certainly can't handle 15A on the 5v rail without crazy ripple. Plus they need a load on the 12v rail to work properly, otherwise everything is out of whack.

>>1032849
Honestly they work great for up to 1A over rated current, but overheat a lot at 3.5A

[Anonymous No.1032880]

This heatsink should be plenty, right?

Hasn't been adhered on her, it's just sitting there.

With a fan on top of it blowing air in to help keep things cool, or one on each sides push/pull.

[Anonymous No.1032881]

>>1032880
Adhered on yet*

[Anonymous No.1032886]

How annoying.
Any advice to reduce the private occurrence of this?

[Anonymous No.1032903]

>>1032886
use a hacksaw. don't use abraisive discs to slice aluminum

[Anonymous No.1032991]

>>1032886

Stop using abrasive discs on aluminum. That doesn't go well.

>>1032852
>certainly can't handle 15A on the 5v rail without crazy ripple

Not entirely sure where you're getting your PSUs, but 15A is nothing for most of them. I've got a few older ones around here (made back when 5V was the highly-loaded rail) that do 40A+ on the 5V line.

>they need a load on the 12v rail to work properly

Not all of them do. Some of them require load on the 5V. Others have the minimum load built into the necessary rail. Even if it doesn't, you can just add the requisite load yourself.

In any event, you're overthinking this at this point. Just do whatever you're going to do and see if it works.

[Anonymous No.1033001]

>>1032852
>>1032880
You obviously had your mind made up before you came here. Face it, you're not really looking for help, you are just looking for someone to blame when it doesn't work like you thought it would.

If you absolutely have to do it your way, I still don't understand why you wouldn't use 6 or 7 of the usb chargers, rather than deliberately overloading 5 of them. It's not like the designer of those usb chargers said 'well, these things can safely put out 3 amps, so I'll rate them for 2'.

The limitation is printed on the packaging for a reason, and exceeding that *will* reduce the lifespan of your project, directly violating your criteria of

>>1032838
>I want to build something that will last

[Anonymous No.1033002]

>>1032880
Make sure you don't touch that side, heatsink included, while you're operating.

It's true that there is no positive/negative distinction for AC, but there is a difference between line and neutral. Modern supplies may want to be connected in a specific way for safety reasons.

[Anonymous No.1033007]

Seriously OP, your argument is basically as follows:

>Bleach is a toxic chemical, and if I drink too much bleach I will die. However, if I only drink a little bit of bleach every day then I should be fine, right guys?

::crowd screams at you not to drink bleach::

>OK guys, I'm going to go drink some bleach now.

[Anonymous No.1033042]

>>1033007
>if I only drink a little bit of bleach every day then I should be fine, right guys?
And I should build up an immunity for bleach, right guys?

[Anonymous No.1033050]

>>1033007
Poor analogy

[Anonymous No.1033063]

>>1033050
So it's ok to treat every day and every glass of water that you drink as an emergency situation? Go ahead and try. Post results.

[Anonymous No.1033065]

>>1033063

All residential tap water in the US is treated with bleach (sodium hypochlorite). Who is your God now?

I bet you'd try to ban dihydrogen monoxide.

[Anonymous No.1033074]

>>1033065
I think that you're thinking that bleach is just hypochlorous acid (HOCL), which they do treat tap water with and is also naturally made in humans, but bleach is actually sodium hypochlorite (NaCLO), which they don't use in tap water because it's dangerous.

Do you even chemistry?

[Anonymous No.1033107]

>>1033074
>dangerous

It is literally the sodium salt of hypochlorous acid

[Anonymous No.1033114]

So many edgelords, so little time. ITT OP decides to burn out a bunch of usb phone chargers so anons start talking about how safe it is to drink bleach. What happened to my /diy/ where people were willing to listen to reason and not immediately devolve in to nit picking?

[Anonymous No.1033131]

>>1033001
If an atx power supply is better then I'll use one, but I've tested the 2 I have laying around and they both register 7v on the 5v rail when I'm not applying a load on the 12v rail, and I'm not wasting energy just to please you and use the atx power supply.

>>1032903
>>1032991
Thanks, I'll look for one tonight. My atx power supplies are generic ones, saw one tested it hardwareinsights and iirc it blew with 14A on the 5v rail. That's part of why I don't trust them for 15A load.

>just do whatever you're going to do and see if it works
Will do

[Anonymous No.1033137]

>>1033074
Wikipedia: A 12% solution is widely used in waterworks for the chlorination of water,

[Anonymous No.1033252]

>>1033131
Still haven't answered the question OP. Why use 5 units and overdrive them instead of using 7 units within spec?

[Anonymous No.1033412]

>>1033252
To save space and keep things even. 15 batteries = 3 per charger.

And these are from the parents shop, not sure they'll appreciate me taking the 5, yet alone 2 more.

Serious question, if there's only a 3% drop in voltage putting out 3A then is it really being pushed over what's its capable of?

Voltage is 5.3v with no load, and it drops to 5.2v under 3A load when I measured it.