Umbrella USB :
Why not just making a USB A->micro USB cable with only 2 wires (5V + GND) in it ?
It would just be more practical than a big/ugly dongle plugged in the wall...
because your Windows computer will provide only a fraction of the available power without correct device identification, so the umbrella has to identify itself to the operating system, ask for the highest possible power and pass through that power to the phone being charged.
Umbrella USB :
Why not just making a USB A->micro USB cable with only 2 wires (5V + GND) in it ?
It would just be more practical than a big/ugly dongle plugged in the wall...
because your Windows computer will provide only a fraction of the available power without correct device identification, so the umbrella has to identify itself to the operating system, ask for the highest possible power and pass through that power to the phone being charged.But in this case, it's exactly that. The umbrella intentionally doesn't have any USB power negotiation chips or bias resistors; it is purely disconnects the data lines.
Umbrella USB :
Why not just making a USB A->micro USB cable with only 2 wires (5V + GND) in it ?
It would just be more practical than a big/ugly dongle plugged in the wall...
because your Windows computer will provide only a fraction of the available power without correct device identification, so the umbrella has to identify itself to the operating system, ask for the highest possible power and pass through that power to the phone being charged.But in this case, it's exactly that. The umbrella intentionally doesn't have any USB power negotiation chips or bias resistors; it is purely disconnects the data lines.
actually it MUST HAVE a chip and it must disconnect the data lines on it's OUTPUT ONLY. otherwise it would be a piece of junk providing only 100mA of charging current.
Quote from: rob77 on June 14, 2014, 12:08:19 AM
actually it MUST HAVE a chip and it must disconnect the data lines on it's OUTPUT ONLY. otherwise it would be a piece of junk providing only 100mA of charging current.
QuoteQuote from: rob77 on June 14, 2014, 12:08:19 AM
actually it MUST HAVE a chip and it must disconnect the data lines on it's OUTPUT ONLY. otherwise it would be a piece of junk providing only 100mA of charging current.
In this case, THIS is a piece of junk, but in most cases, you will have 500mA (most of computers don't really care and just have a 500mA overcurrent protection on USB ports...)
QuoteQuote from: rob77 on June 14, 2014, 12:08:19 AM
actually it MUST HAVE a chip and it must disconnect the data lines on it's OUTPUT ONLY. otherwise it would be a piece of junk providing only 100mA of charging current.
In this case, THIS is a piece of junk, but in most cases, you will have 500mA (most of computers don't really care and just have a 500mA overcurrent protection on USB ports...)
That's actually not true on most modern motherboards. The USB ports typically are 'grouped' in groups of 2 or 4, and have a current limit of 1 or 2A. So yes, technically, you could only draw 500mA per port simultaneously, but you can draw more from a single port if the other ports are not drawing.
That's actually not true on most modern motherboards. The USB ports typically are 'grouped' in groups of 2 or 4, and have a current limit of 1 or 2A. So yes, technically, you could only draw 500mA per port simultaneously, but you can draw more from a single port if the other ports are not drawing.
Hi, my name is Brady Reed, I am currently a honors student and junior in a private high school.
The worse of it is that the person running the indigogo is not the same as the youtube channel.
https://www.indiegogo.com/projects/self-sustaining-electric-generator-prototype
I watched all of the 33 minute video and found it unbelievable... utterly unbelievable!
He should become a politician with statements at the end like "Our method of problem solving is by having a plan of action and then putting the plan into action."
https://www.indiegogo.com/projects/let-s-build-a-planetary-energy-transmitter
I tried to watch the video, got dizzy after some minutes, fast forwarded it several times. I didn't understand what he was trying to show, very unstructured and random explanations. All I see is a battery which powers something and is at 12.4 V at the beginning of the video with no load and at 12.2 V at the end of the video. I can't believe why the Youtube comments to the video are so positive
https://www.indiegogo.com/projects/let-s-build-a-planetary-energy-transmitterUnbelievable that already 700 people fell for the Tesla Tower "test setup".
I believe there is a separate thread on the topic: https://www.eevblog.com/forum/crowd-funded-projects/lets-power-the-world-with-a-tesla-coil/
https://www.indiegogo.com/projects/let-s-build-a-planetary-energy-transmitter
https://www.indiegogo.com/projects/self-sustaining-electric-generator-prototype
I watched all of the 33 minute video and found it unbelievable... utterly unbelievable!I tried to watch the video, got dizzy after some minutes
I tried to watch the video, got dizzy after some minutes, fast forwarded it several times. I didn't understand what he was trying to show, very unstructured and random explanations. All I see is a battery which powers something and is at 12.4 V at the beginning of the video with no load and at 12.2 V at the end of the video. I can't believe why the Youtube comments to the video are so positive
It's completely bizarre. There are three batteries but no real explanation of what each one is for except one is running the inverter.
Then there is the auxiliary motor - why does it need one? What does it actually do apart from start the thing which it seemed to do perfectly well without it to start with!
There are huge losses in the system - the drag of the auxiliary motor when it's running, the fact that the auxiliary motor is powered by a bench power supply, which is powered by an inverter... why not just use a 12V motor?
Then there's the statement about how you should always let it run down on his own, followed by him stopping it once by hand and another time when he removed the rubber band for the auxiliary motor!
And then there's the quantity of completely different switches and them being switched for no apparent reason!
Just noticed that at 5:37 he calls it a 'four-way bridge rectifier' - what's one of those? Full-wave rectification or bridge rectifier, isn't it?
The 'unbalanced battery bank charging circuit' looks like a bit of terminal strip with a handwritten label!
I will believe it when I see it in a Faraday cage whilst in a glass box, running for 30 days with no external inputs.
Probably the dodgiest of the dodgy: https://www.kickstarter.com/projects/324283889/potato-salad
Yes, he's making potato salad, but he hasn't even decided which kind he will make yet. Given the variety of potato salad recipes out there, contributors really have no idea what to expect. And yet, he's being funded.
Probably the dodgiest of the dodgy: https://www.kickstarter.com/projects/324283889/potato-salad
Yes, he's making potato salad, but he hasn't even decided which kind he will make yet. Given the variety of potato salad recipes out there, contributors really have no idea what to expect. And yet, he's being funded.