Open source - travlers adaptor anti fire add on (in series with .. ) - Page 1
Forum section: electronics / projects

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 22, 2015, 08:55:13 am
content: As you may have guessed , my assumpion is shitty el-cheapo adaptors have no minimal load on the 5V output rail and hence vornabole to no load situationsI have no real in depth reaserch to those cases , but my intuition when i hear my 25$ adaptor noisy when my phone is unpluged , is that the transformer is saturated and hence the noise , please correct me if I'm wrong here .50-100mA load should solve that and perhaps save the day for most cases , and that leads me to my call to you guys to push A open source project , leading someone to mass produce "Add on" to most adaptors , simply drawing 250-500mW in series with the load we call our cell phone , so that has to be just plug and usb port ad small and durabole as possible , perhaps smd/To-92 solution , 1-5$ deviceHoping to statistically lower the fire cases , please write here your opinion and input , i want to hear itThank you in advance

author: Rerouter
author_rank: Super Contributor
timestamp: September 22, 2015, 09:04:08 am
content: The fire cases are purely that the adapters are rubbish, no matter what you put on the output is going to prevent that, Either a component is grossly underrated or the transformers insulation is so thin that voltage ends up where it shouldn't,Almost no plug packs have a mains transformer anymore, They rectify to ~340V DC then pulse through a isolation transformer to make a crude 5V, entering a hiccup mode when unloaded, as the output caps slowly droop, causing it to kick over for another pulse,

author: amyk
author_rank: Super Contributor
timestamp: September 22, 2015, 09:54:02 am
content: If anything, the cheap adapters are failing because of transients on the mains side since they don't have any internal surge protection. It's nothing to do with the load. Plugging them into a surge protector will help.

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 22, 2015, 10:10:12 am
content: My will is to prevent failing into fire .Statistically reduce the odds , if ther's some practical way i'd like to hear about it .As you can see i thought about it very little , just one way of thinking , hence asked you guys for some input .If so that means nothing can be done that way ?

author: wraper
author_rank: Unknown
timestamp: September 22, 2015, 10:31:11 am
content: Quote from: eevblogfan on September 22, 2015, 08:55:13 amOnly crap chargers will feature some internal load beyond what voltage stabilization circuit is already consuming as it increase power consumption and doesn't help to save environment at all. Also they won't get energy efficiency certifications.QuoteQuote from: eevblogfan on September 22, 2015, 10:10:12 amAdding the load will only increase power consumption and heating, and reduce it's life. Buzzing might be because it is skipping cycles. If the adapter is capable of catching fire, it is Chinese crap (likely counterfeit) and shouldn't be able to pass safety tests anyway.Quote

author: wraper
author_rank: Unknown
timestamp: September 22, 2015, 10:34:31 am
content: QuoteSpecial product for members of anti-environmental movement.

author: DmitryL
author_rank: Regular Contributor
timestamp: September 22, 2015, 10:43:03 am
content: Quote from: wraper on September 22, 2015, 10:34:31 amCome on! Put a blue LED inside and call it "Loadizer". That might work!

author: Siwastaja
author_rank: Super Contributor
timestamp: September 22, 2015, 01:00:21 pm
content: Sorry - chargers that go in flames are fundamentally broken and cannot be fixed with any limitation of output current or any other external circuit. You won't even get much statistical benefit; the most common failure mode isn't (probably) a simple overload.The only way is to support high-quality charger design.

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 22, 2015, 01:23:23 pm
content: HeyI am happy to hear your commentsNo i am not supporting low effeciancy , i am supporting seafty as my first concern .No i don't give A toss about bennefit of sneak oil products it wasn't any final idea , so don't get lough out of me , not that wayI don't feel any safer rhough i can now see that probably no one care enough about mains safety in those products .. money passes those needs any time he can .Well thank you anyhow

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 23, 2015, 03:33:09 am
content: Some good quality PSUs will make noise at light loads as well. That's especially true of variable output units that often have to implement switching frequency adjustment (PFM mode, AKA period skipping or period stretching depending on implementation) to work properly over the entire output voltage range.

author: eevblogfan
author_rank: Frequent Contributor
timestamp: September 26, 2015, 03:27:06 pm
content: Thank you guys i really uppreciate those commentsNext time i should scratch my head more before posting such ideaCheers