Re: J107 Tantalum cap burning inside a USB hub?
The problem is that when it occurred, I wasn't in the car. The car is constantly powering the USB port to record data to a dashcam, so even if there was a switch on it -- most likely the failure happened when I wasn't there to notice it.
Hopefully the manufacturer put the appropriate fire-resist/self extinguishing plastic around the USB hub. (Maybe they did since the plastic only melted and didn't fully catch fire)....
zman78
Member
Last Activity: 08-04-2021, 01:33 PM
Joined: 06-28-2021
Location: Los Angeles, CA
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Re: J107 Tantalum cap burning inside a USB hub?
Ahhh interesting, so the USB is a 5V power supply, and the J107 is a 6.3 volt cap?
So do you think there wasn't enough voltage margin for spikes that may have caused this failure?Leave a comment:
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Re: J107 Tantelum cap burning inside a USB hub?
Oops for some reason the photo didnt post in the original, I'm attaching the photo again....Leave a comment:
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J107 Tantalum cap burning inside a USB hub?
I have a USB hub specifically to fit in my car. It stopped working and i saw a burned J107 capacitor (see picture). It looks like it might have briefly caught fire as you can see the plastic under the capacitor deformed. It was hot enough that the other side (outside of the plastic box) also melted a little.
I'm curious - does anyone know what might cause a cap like this to catch on fire like that? Is it just a random manufacturing defect that can happen to anyone, or was there a design issue with the USB hub?
Also, does anyone know if these can burn hot enough to actually... -
Re: Screw-In Barrel Adapter for LED light array gets really hot?
I decided to buy the JOVNO supply i linked earlier and it solved my problem! Thought it would be good form to report what the final solution was.
The JOVNO supply came with a matching connector. This time the connector screws heated/stabilized to about 101 degrees, and the barrel connector side was a few degrees warmer. Same amount of torque, same wires as before.
The power brick itself also stayed a relatively cool 102 degrees (versus 145 degrees with the other power brick.)
...Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
It does not, when not connected (barrel connector side) but still connected to AC power, neither the power brick nor the end of the barrel plug get hot....Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
I found this one searching on amazon:
[url]https://www.amazon.com/dp/B08763KYFR/ref=emc_b_5_t[/url]
Interestingly it seems to come WITH a matching screw-in terminal. Anyone know if I might have better luck with this? The brand is "JOVNO" which i don't recognize. anyone know if that's a reasonable brand?Re: Screw-In Barrel Adapter for LED ...mc_b_5_t[/url]...Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
Actually, I don't mind spending on a better PSU. This just happened to be the one i found on Amazon without knowing any better what was a good, and what was a bad PSU.
Any recommendations on links of what to buy (perhaps also WHERE to buy in case Amazon doesn't have any good ones)? I need 24 Volts 2 Amps for 12-14 hours per day. Hopefully something that can last about 3-5 years (rated lifetime of the LEDs im running)
Thanks!...Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
Actually both of them are getting hot. the connector a bit hotter (and faster). I noted the connecter being a problem because as it heated and cooled it broke the connection so the lights wouldn't turn back on the next day.
But the PSU is definitely getting hot as well. It is nearly at it's limit using 2A of (3A rated) with my 120V supply. The product actually claims 6A @ 24V, but from the comments on Amazon this only applies if it's sourced with 240V? (I don't understand how that works)....Last edited by zman78; 07-02-2021, 02:44 PM.Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
Thanks for the info! I'm ok with making it permanent so I will cut and solder. It would have been nice to be able to swap a different power supply in and out easily (for example if this one also fails).
It jumps to around ~110 degrees within a few minutes, but then slowly gets to 140f. Maybe about 20 minutes until it's fully warm.
By the way since you know the DC power supplies well -- the one I bought, the case temperature of the brick also gets to about 140 degrees after...Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
Oh wow you're right! I took a look inside with a flashlight. The power supply has two very thin strips of conductor to make contact in its barrel plug. Whereas the same-gendered screw-in terminal has a solid conductor all around on the inside.
How did you see that from just the picture on Amazon? Do you think the heat could be because the mismatched connectors?
I guess i am better off just cutting the thing off and hard wiring it....Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
Maybe I need to just chalk it up to the cheap connectors from an unknown brand name? I tried to crank that + terminal as much as i could and didn't get much better.
So let's say I ditch the screw-in terminals. Instead, i cut off the barrel connector from the power supply side. Does anyone know if i will get 3 wires or two wires? I saw a different power supply (NOT the one i bought!!) [url]https://www.amazon.com/ALITOVE-100-240V-Adapter-Converter-5-5x2-1mm/dp/B01GC6VS8I/[/url] shows there...Last edited by zman78; 07-01-2021, 06:20 PM.Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
Only that I went back to my order history and verified the size of the barrel adapter on the power supply based on their advertising. Just to make sure i didn't do a bone-head move and ordered mismatching size! I don't have any tools to actually measure it though so i'm entirely depending on their specs being correct....Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
OK Starting with cold, I measured the following points:
P1) The screw attached to the white wire
P2) The screw attached to the red wire
P3) The exposed metal ring of the screw-in adapter side
P4) The exposed metal ring of the power supply side
They tracked pretty closely with each other, but there was a consistent temperature gap between them.
- The red screw (P2) was 3 degrees hotter than the white screw (P1).
- The white screw...Leave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
Thanks for the suggestion, I double checked and the power supply has a 2.1mm center and 5.5mm outer dimension. Looks like it "should" match the screw-in barrel connector well. This is the exact power supply in question:
[url]https://www.amazon.com/gp/product/B01CYIFOHE/[/url]
I had a bag of 5 of the screw-in terminals and tried swapping out to a different one in case one of them was bad, and had the same issue as well.Re: Screw-In Barrel Adapter for LED ...ay gets reallyLeave a comment:
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Re: Screw-In Barrel Adapter for LED light array gets really hot?
Thanks for the reply! I attached a photo of the attachment to help describe the situation.
I took a thermocouple and tested the temperatures at various points. Both the positive and negative screw are at 141 degrees. The metal parts of the barrel connector still showing (both the top and bottom halves) are also 141 degrees. The black/plastic parts reads 133f but that's probably just because of the poor heat transfer through the non metal material.
So it seems like the whole assembly...Leave a comment:
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Screw-In Barrel Adapter for LED light array gets really hot?
Hi All,
I have an LED Light array that had a built-in AC-DC 24v 45 watt power supply. The power supply failed so I desoldered the LED Light array power input wires from the power supply and then screwed it into barrel connector jack (ends still tinned with the original solder).
This is the barrel connect or jack [url]https://www.amazon.com/gp/product/B07Q6YMM6F/[/url]
Then I bought an external 24Volt/3Amp power brick (with same size barrel connector output) and plugged it in.
Everything works fine, except that the screw-in barrel connector... -
Re: New Members - please post your introductions here
Hello from Cali,
Looking to get information on DIY repairing some electronics and it seems like there are many knowledgeable and friendly folks here!
Thanks!Leave a comment:
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