Author Topic: Dave's power supply mods.  (Read 42552 times)

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Offline Zad

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Re: Dave's power supply mods.
« Reply #100 on: March 08, 2012, 12:40:39 pm »
In this weeks' The Amp Hour, Dave points out that the regulator chip is now available in a switched mode equivalent.

Just sayin'....


Offline EEVblog

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Re: Dave's power supply mods.
« Reply #101 on: March 08, 2012, 05:07:37 pm »
In this weeks' The Amp Hour, Dave points out that the regulator chip is now available in a switched mode equivalent.

Close, but no cigar.

I think I'll shoot a new video tomorrow revealing all.
Rev 3 is coming along nicely and I'm quite pleased with this version. I've eliminated some chips, lowered some costs, increased some functionality, and improved the build at the same time.

Dave.
 

Offline dougg

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Re: Dave's power supply mods.
« Reply #102 on: March 08, 2012, 06:20:58 pm »
Just tried to hack up a USB power supply from a 5 volt, 2 amp switched mode wall slug. With USB D+ and D- floating it didn't work on two different tablets (HP and RIM). Then I followed Dave's power supply schematic which puts 2 volts on both with separate resistor dividers. That did not work either. The appropraite reference to look up is "USB dedicated charger". Seems that the USB folks standardized shorting D+ and D- together circa 2010. When I did that, it worked.
 

Offline EEVblog

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Re: Dave's power supply mods.
« Reply #103 on: March 08, 2012, 06:47:30 pm »
Just tried to hack up a USB power supply from a 5 volt, 2 amp switched mode wall slug. With USB D+ and D- floating it didn't work on two different tablets (HP and RIM). Then I followed Dave's power supply schematic which puts 2 volts on both with separate resistor dividers. That did not work either. The appropraite reference to look up is "USB dedicated charger". Seems that the USB folks standardized shorting D+ and D- together circa 2010. When I did that, it worked.

The iPhone/Pad/Pod is apparently different and requires those voltages.

Dave.
 

Online Monkeh

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Re: Dave's power supply mods.
« Reply #104 on: March 09, 2012, 12:22:11 am »
Just tried to hack up a USB power supply from a 5 volt, 2 amp switched mode wall slug. With USB D+ and D- floating it didn't work on two different tablets (HP and RIM). Then I followed Dave's power supply schematic which puts 2 volts on both with separate resistor dividers. That did not work either. The appropraite reference to look up is "USB dedicated charger". Seems that the USB folks standardized shorting D+ and D- together circa 2010. When I did that, it worked.

The iPhone/Pad/Pod is apparently different and requires those voltages.

Dave.

Yes, Apple aren't big on this whole standards thing.
 

Offline sacherjj

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Re: Dave's power supply mods.
« Reply #105 on: March 09, 2012, 01:05:26 am »
I thought the D+ D- tie was a change that allowed 1 A through USB for charging, rather than just 500 mA.  If those are not shorted, you are only allowed to pull 500 mA. 
 

Offline mtkaalund

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Re: Dave's power supply mods.
« Reply #106 on: March 09, 2012, 01:19:06 am »
I thought the D+ D- tie was a change that allowed 1 A through USB for charging, rather than just 500 mA.  If those are not shorted, you are only allowed to pull 500 mA.

I believe that the specification for the USB standard, says that 500mA is the maximum allowed current through an USB port. But correct me if I am wrong :D
"Keep buggering on" -- Winston Churchill
VIR => V = I*R, neat ;)
 

Offline Hideki

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Re: Dave's power supply mods.
« Reply #107 on: March 09, 2012, 03:08:13 am »
500 mA was correct for a long time, but as time went by various useful things were added to the specification.

See http://www.usb.org/developers/devclass_docs for the Battery Charging Specification documents.
 

Online Monkeh

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Re: Dave's power supply mods.
« Reply #108 on: March 09, 2012, 03:29:09 am »
I thought the D+ D- tie was a change that allowed 1 A through USB for charging, rather than just 500 mA.  If those are not shorted, you are only allowed to pull 500 mA.

I believe that the specification for the USB standard, says that 500mA is the maximum allowed current through an USB port. But correct me if I am wrong :D

500mA is the maximum current a USB 2.0 port can supply to a device, unless it complies with the USB Battery Charging Specification. Shorting D+ and D- is required to indicate a dedicated charging port, which can supply up to 5A.

USB 3.0 includes support for up to 900mA at reduced voltages (making allowance for cheap, nasty cables, basically).
 

Offline dougg

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Re: Dave's power supply mods.
« Reply #109 on: March 09, 2012, 03:34:31 am »
I thought the D+ D- tie was a change that allowed 1 A through USB for charging, rather than just 500 mA.  If those are not shorted, you are only allowed to pull 500 mA.

I believe that the specification for the USB standard, says that 500mA is the maximum allowed current through an USB port. But correct me if I am wrong :D

"The great thing about standards are that there are so many to pick from." You were correct but as one standard supersedes another you are probably not correct now. I am familiar with SCSI standards and recent USB-3 external disks should be using UASP rather than the (dreadful) mass storage class (block mode). I'm still looking for the first example in a real product.
 

Offline EEVblog

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Re: Dave's power supply mods.
« Reply #110 on: March 13, 2012, 09:35:07 pm »
Part 11 is rendering now, the biggest and most rambling episode yet, at 1:15min!  :-[

The true original purpose of the PSU will be revealed, along with the substantial changes.

Damn, 1:15min, I must be insane. Now I'm thinking if there is somehow a way to split it?...

Dave.
 

Offline markus_b

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Re: Dave's power supply mods.
« Reply #111 on: March 13, 2012, 10:08:54 pm »
Dave, just keep it like it is. People always can fast-forward !
Markus

A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible.
 

Online firewalker

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Re: Dave's power supply mods.
« Reply #112 on: March 14, 2012, 12:07:58 am »
I am guessing 4xNiMh batteries and a boost convert.

Alexander.
Become a realist, stay a dreamer.

 

Offline Tooms

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Re: Dave's power supply mods.
« Reply #113 on: March 14, 2012, 03:52:13 am »
Part 11 is rendering now, the biggest and most rambling episode yet, at 1:15min!  :-[

The true original purpose of the PSU will be revealed, along with the substantial changes.

Damn, 1:15min, I must be insane. Now I'm thinking if there is somehow a way to split it?...

Dave.

love them as they are, so dont split it.

Tooms
 

Offline sacherjj

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Re: Dave's power supply mods.
« Reply #114 on: March 14, 2012, 07:33:07 am »
Am I the only one that checked about a dozen times today, each time when I got back to my desk, for a new 1:15 monster video on YouTube?
 

Offline Noize

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Re: Dave's power supply mods.
« Reply #115 on: March 14, 2012, 09:18:10 am »
Am I the only one that checked about a dozen times today, each time when I got back to my desk, for a new 1:15 monster video on YouTube?

No  :)
 

Offline PeterG

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Re: Dave's power supply mods.
« Reply #116 on: March 14, 2012, 11:55:13 am »
Its getting on  for midday. I am thinking something may have gone horribly wrong with the video causing delays. :(

Regards
Testing one two three...
 

Offline IanB

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Re: Dave's power supply mods.
« Reply #117 on: March 14, 2012, 12:49:45 pm »
Yup, it's been hours and it hasn't appeared yet. I think Dave broke YouTube  8)
I'm not an EE--what am I doing here?
 

Offline BravoV

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Re: Dave's power supply mods.
« Reply #118 on: March 14, 2012, 12:59:46 pm »
Nah .. after waking up this morning, Dave decided to scap and redo new version again, and going to re-shoot the vid ...

....j/k. :D

Seriously, I think he hasn't upload it yet and probably he was rendering it overnight.

Offline EEVblog

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Re: Dave's power supply mods.
« Reply #119 on: March 14, 2012, 01:45:48 pm »
I decided to try splitting into two, a hardware/case part, and the schematic part.
Plus I had to baby sit Sagan for half the day!

Dave.
 

Offline mtkaalund

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Re: Dave's power supply mods.
« Reply #120 on: March 14, 2012, 08:18:47 pm »
I decided to try splitting into two, a hardware/case part, and the schematic part.
Plus I had to baby sit Sagan for half the day!

Dave.
When can we expect the schematic part? I was looking forward to see it, but i like the system design aspect of this video.
Sagan, an electronic engineer in the making?
"Keep buggering on" -- Winston Churchill
VIR => V = I*R, neat ;)
 

Offline EEVblog

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Re: Dave's power supply mods.
« Reply #121 on: March 14, 2012, 09:12:46 pm »
It STILL doesn't have Bluetooth!!?

It's got a socket with SPI interface, plug in anything you want!

Dave.
 

Online firewalker

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Become a realist, stay a dreamer.

 

Offline PeterG

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Re: Dave's power supply mods.
« Reply #123 on: March 15, 2012, 09:03:55 am »
To my thinking, Bluetooth makes more sense than Ethernet. I think Ethernet defeats the purpose of being battery powered and portable.

I would have liked to see the accuracy increase rather than decrease. It would be great to have 1mV and 1mA accuracy but i feel that is outside the scope of this project for now.

But thats just my 2 cents.

Regards
Testing one two three...
 

Offline McMonster

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Re: Dave's power supply mods.
« Reply #124 on: March 15, 2012, 09:23:39 am »
To my thinking, Bluetooth makes more sense than Ethernet. I think Ethernet defeats the purpose of being battery powered and portable.

I would have liked to see the accuracy increase rather than decrease. It would be great to have 1mV and 1mA accuracy but i feel that is outside the scope of this project for now.

But thats just my 2 cents.

Regards

I agree, it'd be nice to figure out a way to either plug a Bluetooth or Ethernet module there.
 


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