EEVblog Electronics Community Forum
Electronics => Open Source Hardware => Topic started by: Schnibbelwind on January 20, 2015, 08:48:53 am
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Hi,
I'm a electrical engineering student in the first year from Germany and follow the EEVblog for about 3 years.
Yesterday I saw the ?Supply videos on Dave's Youtube Channel and thought, awesome thing. But what happened with the project? Was it compleded? Can I buy it anywhere?
Patrick
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Back burner.
When Dave gets inspired, he does some work on it.
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Was it compleded? Can I buy it anywhere?
No, and No.
Probably one of the first things I'll get the new hire to work on.
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Ah okay.
I got one thing that can be added to the microSupply, a USB Powerbank function
Just an idea ;)
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I think this project is a gap in the market.
still have nowhere to find a device like this
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I think this project is a gap in the market.
still have nowhere to find a device like this
And the market hasn't changed since I first had the idea 5 years ago.
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Id be interested in one of those hell even putting it together my self
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I think, the schematics on the eevblog-website are a good start. One should be able to build a working device out of those.
Alternatvely, a design based on the LTC1871 might also work (Voltage Regulation with digital Pot and current regulation by applying a voltage at the ITH-Pin). At least in LTSpice variable current limiting works this way :)
For lower noise, a linear regulator could be put in series with the LTC1871.
A LTC1624r should work too. The output-noise is kinda high though if used in SEPIC-Mode (desirable because of output-voltage "not limited" by Input-Voltage and iherent short circuit-protection) and needs an appropriate Filter.
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I played around with an LT3081 version in LTSpice the last weeks and honestly think there are some issues in the uSupply USB revB design.
Firstly, I guess it will be pretty slow. Especially since the opamp supply to generate the Vset voltage is created from the preregulator voltage which again raises only with Vset.
Besides, with this kind of design, it will be hard to have little ripple in current regulation and fast regulation. It's always a tradeoff.
Also in a short circuit situation, it won't be able to limit the current as much a it should do. Issues include
- LM324 not reaching 0V (up to 20mV)
- Vce saturation of the NPN (about 100mV)
- offset current coming from the LT3080 and always dropped at the 120Ohm resistor (-> 1.2mV), for the LT3081 this is even worse due to 50µA current source
- constant 5mA current source not working below 0.7V (which is the case in a short circuit situation).
So the voltage can't be dropped to 0 and thus the current flowing will be much larger than the set limit.
These issues can be partly overcome by using two opamps, a N-FET instead of the NPN and a negative rail supply.
Also the constant current source can be reworked to use FETs which extends the range to below 0.1V or so.
One more thing: the LT3080 used in Dave's design uses separate IN and VControl pin where the manual says
"The current flow into this pin is about 1.7% of the output current" which means 17mA at 1A.
The current measured is however only the one going into the IN pin. Which looks correct at first sight,
but the current through the load is Iin + Icontrol - Iset (where Iset is fixed to 10µA and thus can be ignored).
So when the current measured at the shunt is 1A, the current going through the load is 17mA higher.
The LT3081 is different in that it has only one common supply/input pin.
Also note that a clamping diode is missing from Vset to Out. Even for the LT3081 which has internal clamping diodes,
the manual warns that the internal clamping diodes are build to handle only up to +/-10V but e.g. a hard short circuit
on the output while Vset is still 15V could possibly damage the device.
Note that this clamping current is also not handled by the current limitation. It should flow only shortly though
to remove the charge from the Vset capacitor.
I have something that is somewhat working in LTSpice, but I'm not 100% happy with it.
As discussed above, it's hard to find a tradeoff between fast current regulation and low ripple.
When playing around with low resistance short circuits and/or high capacity loads, things soon get ugly.
Partly this might be caused by the simulation and using to "ideal" parts.
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Was it compleded? Can I buy it anywhere?
No, and No.
Probably one of the first things I'll get the new hire to work on.
Any news about it?
What about Dave2?
Are there hopes uSupply project would be resumed? What about using KiCad?
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Regarding my earlier post: Playing around with the voltage on the Ith-Pin of the LTC1871 does NOT work! Contrary to what LTSpice was promising me, the entire circuit oscillated like crazy (not only the Power-Part, but also the 5V-Rail powering the DAC with which I was applying a voltage to the Ith-Pin). Using an N-FET as a variable resistor as the current sensing resistor should be working though.
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Any news about it?
What about Dave2?
Are there hopes uSupply project would be resumed? What about using KiCad?
From bits and pieces from the Amp Hour, Dave2 started working on it.
Will be interesting to see how professional it will look.
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Any news about it?
What about Dave2?
Are there hopes uSupply project would be resumed? What about using KiCad?
From bits and pieces from the Amp Hour, Dave2 started working on it.
Will be interesting to see how professional it will look.
It would be interesting if Dave2/David2 shows some sneak peak about it? What about a video? That young guy seems nice and skilled! ;)
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It's been seven years -- where are we at? The previous posts don't say which revision they're discussing so I have no idea if their comments are relevant to RevC (current as of this posting) or not.
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It's been seven years -- where are we at? The previous posts don't say which revision they're discussing so I have no idea if their comments are relevant to RevC (current as of this posting) or not.
I've shown were it got to on many live shows and some other videos.
It has not been actively developed for 2 years now.
It got to a working final product, but needed a lot of extra work to go into production, which is something I have no interest in doing.
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seems like a great idea.
Could it also be used to power an Arduino VIA 18650?
Are the schematics available in Gerber format or other? (If only PDF, how to import them to kicad or firtzing?)
Thanks,
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That Arduino can be powered via the on-board USB. What would you gain with using a (µ)Supply?
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That Arduino can be powered via the on-board USB. What would you gain with using a (µ)Supply?
Ahh I was mislead by the project name, This is more of a stand alone Power supply.
I was thinking it was a 18650 shield for Arduino ( with a programmable voltage supply output)
Looks like another great Dave Jones project, Nice and simple.
There are few alternatives, MiniWare MDP-XP _ Expensive but quite nice
Or DIY a USB PD Powered RD3005 - seems like a great idea.
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I've shown were it got to on many live shows and some other videos.
It has not been actively developed for 2 years now.
It got to a working final product, but needed a lot of extra work to go into production, which is something I have no interest in doing.
Would you consider open-sourcing the plans, and/or offering a partial kit?
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I've shown were it got to on many live shows and some other videos.
It has not been actively developed for 2 years now.
It got to a working final product, but needed a lot of extra work to go into production, which is something I have no interest in doing.
Would you consider open-sourcing the plans, and/or offering a partial kit?
The source code is open source:
https://gitlab.com/eevblog
No to partial kits and likely all the stuff, as I will get stuck with endless suppprt requests for the next decade.
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It's shown in the latest mailbag @20:40
https://www.eevblog.com/2022/11/28/eevblog-1516-mailbag-bonanza/ (https://www.eevblog.com/2022/11/28/eevblog-1516-mailbag-bonanza/)
Dave is also buying an SMT machine:
https://www.eevblog.com/forum/manufacture/choosing-a-desktop-pick-and-place-machine/ (https://www.eevblog.com/forum/manufacture/choosing-a-desktop-pick-and-place-machine/)
So my guess would be he's ramping up for production of this gadget.
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Everybody has a ?supply project. The one where you solve -1 one requirements and add 2 more each time you touch it.
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So my guess would be he's ramping up for production of this gadget.
Sorry, nope. Or at least no immediate plans for that project.
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So my guess would be he's ramping up for production of this gadget.
Sorry, nope. Or at least no immediate plans for that project.
On esthetics alone, it is a very attractive gadget. It is shame that hard work isn't going to be realized. I can understand not producing it. I am unlikely to have purchased one even though it is a sexy beast
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It is shame that hard work isn't going to be realized.
Well, a lot of interesting content on Youtube etc. was realized, which is in fact Dave's main product. So I would consider this project a success. :-+
I sure learned a lot, for example about about manufacturing options like custom LCDs and keypads. Thanks again for teaching us, Dave!