burning jumper cables on 5V 10A

Hello,

I’m pretty new here and got not very much knowledge about electronics… yet. But I already got some great skills at burning arduino jumper wires. Now I need to know why this happend?

I took a power supply (5V 10A). connecting two jumpers directly to the plug and into the breadboard. I was using a 4700 uF 10V capasitor between this power supply and the 5V / GND pins on a W2812 LED Strip.
Power on → very hot cables. melting, smoking and close before burning. + hot cap … the LED Strip didn’t light up and still seems to be ok.

Please help me to understand what happend here.

greets, Tom

It's not clear from your pictures but I suspect you had the capacitor the wrong way round. They do not like reverse voltage and those wires won't take 10 A for long!

Russell.

thanks. so it seems to be a bad idea to put the long one into (-). If I switch them, it should work?

That capacitor looks to me like the wrong way round. The caps I have like that have that broad blue band as -ve, you seem to have connected that to the +ve.

Your post brings up three points.

  1. You should not be using bread board, if you must use it then do not exceed 0.5A through any of the tracks, the spring contacts will not thank you.

  2. Using a 10A power supply is very unforgiving of any mistakes, use one with a lower capacity.

  3. That way of connecting to the power jack while ingenious is dreadful, especially if you are expecting to take 10A from the supply.

If I switch them, it should work?

I think you might have blown it already, I would not use that cap again.

is there any way to test the cap? Because I don't have a second one and really like to work on it today.

Grumpy_Mike:

  1. You should not be using bread board, if you must use it then do not exceed 0.5A through any of the tracks, the spring contacts will not thank you.

  2. Using a 10A power supply is very unforgiving of any mistakes, use one with a lower capacity.

But I need that 10A. I got 150 LEDs with W2811 (W2812) controllers. Each 60mA on max.

Grumpy_Mike:
3) That way of connecting to the power jack while ingenious is dreadful, especially if you are expecting to take 10A from the supply.

On the first image you can see the white “jack slot” (however you call this part). I replaced it for the second run, because I thought that would be the problem.

wohoo... it becomes hotter each time.

third try: I reversed the cap. the LED Stip got light. But the cables are still burning. Damn it! They were melting the breadboard. :smiley: Do you really think it's because I still fired up the cap or should I reconsider using power supplies from china?

I'm not going to start a fourth barbecue on my desk. But I am still wondering. How would you connect a 5v10a DC power supply to an W2812 LED Strip which may need 9 ampere ?

If you have burned out a piece of electronics by mistake, there is no way back.
You need a new component, no matter how hard you need it right now and here.

If you have a multimeter with an ohms range, you can test the capacitor - out of circuit that is - by doing an ohm measurements.
On the high ohm range, reading on your multimeter should slowly increase to max reading, indicating the capacitor is still good.
If the reading settles at some smaller value, the capacitor has gone to the fields of dead electronics.

Observe the correct polarity !

is there any way to test the cap?

Lots of ways, for example charge it up to 5V through a resistor, say 1K. Measure the voltage and see if it is stable at 5V. Then disconnect the power and see that it stays close to 5V for at least 5 seconds.

Those wires and that breadboard can not cope with 9 Amps.

Also pls note :

Working with currents much higher than 1 amp is really not recommanded in breadboard setups.
The breadboard is not designed to carry that high currents.

Instead use an off board connection with soldered wiring using a gauge that can carry such high currents.
For example use a length of standard desktop lamp wire.

Are the blue and red burnt leads the output from the PSU. If they are then ask yourself why these are burnt but no components or leads on the plugboard. The white socket that these two leads are connected to have a switch on them to disconnect one source of supply when an external source is connected. Is there a possibility that you have connected to a shortened contact on this socket such that when you plug in your connecting lead you are placing a short across the PSU. This can be simply confirmed by disconnecting the plug-board and see if the short still exists. Much better to get yourself a test meter !!

...... should I reconsider using power supplies from china?

The power supply is not the problem - it is doing it's job - it is supplying power!

0.1A is about the maximum you can reliably expect a breadboard contact to handle,
you might get away with 0.5A in practice most of the time. 10A no chance at all.
You need thicker wires and terminal blocks / high current connectors or solder tag
joints for large currents.

Some of the cheap jumper wires are not designed to carry power at all I have found
and 100mA might be pushing it with them.

For larger currents on a breadboard using multiple high quality jumper wires can be
helpful.

Hi,
morg, the capacitor has a marking on the side of it indicating Negative, - . This is the short lead.
Positive is the long lead.

The capacitor is now useless to you, in fact it is a short circuit and will not work in circuit again.

If you are using high currents as 10A you need to fit fuses, use decent sized wire.

The protoboard is not suitable for 10A or even 1A, you need to make a terminal board with your LEDs connected to it, separate fro the arduino, to handle the LED power requirements.

You are going to have to spends some time and hardware on terminating your LEDs safely before you have a fire.

Do you have a DMM?

Tom..... :slight_smile:
I have found if you connect an electrolytic the wrong way round and it even just gets warm, forget trying to use it the right way round, it might work, but ten to 20minutes later it won't.

Hi,
Capacitor in attached picture is 120mm high plus extension due to failure.

Tom… :slight_smile:

morg:
is there any way to test the cap? Because I don't have a second one and really like to work on it today.

Well, tough titties then!

Let it die in peace. In fact, give it a decent burial.

Go find something else to destroy today. :grinning:

When I'm testing I usually have my power supply set to 200 mA. It might still destroy a component, but at least it won't set the place on fire!

Yes, the benefit of a proper lab power supply :wink:

Russell

Did you notice the smoke ?
This is what electronis is all about : dont ever, ever, EVER let the smoke get out.

Its so darned impossible to put the smoke back in again.
Thats why it wont work after a smoke session.

Hereby my flowers to the funeral of a dear capacitor, that really did its best to survive human behaviour.