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bigmik

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Joined: 20/06/2011
Location: Australia
Posts: 2947

Posted: 10:36am 23 Mar 2016

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Hi All,

I have just found THIS Adjustable PSU on Banggood.com

It seems pretty impressive for $6.66AUS inc shipping..

It requires 5-23V (I suggest a 19V laptop power supply} and it offers 0-16.5V @3A (peak current so probably means continuous current at somewhat less than 3A)

Anyway for the price it looks OK.

Regards,

MIck

Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<

HankR
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Joined: 02/01/2015
Location: United States
Posts: 209

Posted: 10:58am 23 Mar 2016

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Great find, Mick.

I wish they provided a spec for ripple and noise, but one of us can measure that and report our findings. For the price I'll probably get one just out of curiosity.

My lab is brimming with an assortment of high grade voltage/current regulated supplies so don't need another, although this would be smaller than any of those, but switchers are not the best for general lab use either.

As far as this one lacking current limiting, as has already been stated, current limiting during development of projects is almost an essential. However, it might not be too big a deal, for those desiring current limiting even if it were fixed at 3 amps, to add that on as an outboard, optional accessory.

Justplayin

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Joined: 31/01/2014
Location: United States
Posts: 327

Posted: 11:30am 23 Mar 2016

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bigmik said I have just found THIS Adjustable PSU on Banggood.com

Wow, I was just looking at that on Banggood before checking messages here. For $5US I was thinking about giving one a try.

--Curtis

Edit: Ordered... Now I have to wait for that slow boat from China.

Edited by Justplayin 2016-03-25

I am not a Mad Scientist... It makes me happy inventing new ways to take over the world!!

plover

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Joined: 18/04/2013
Location: Australia
Posts: 305

Posted: 03:20am 24 Mar 2016

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Whoever get their hands on one of these, please report the IC used, I would like to see the circuit diagram.

Justplayin

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Posted: 05:58am 24 Mar 2016

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Just received notice my order has shipped. If all goes well, I should have it in 7-10 days.

--Curtis

I am not a Mad Scientist... It makes me happy inventing new ways to take over the world!!

MicroBlocks

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Joined: 12/05/2012
Location: Thailand
Posts: 2209

Posted: 07:55am 24 Mar 2016

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Add a resetable fuse in the lead to your prototype and you have a current limited power supply. :)

Joking aside, i like the one Metherp made. Looks simple and effective.

Microblocks. Build with logic.

robert.rozee
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Joined: 31/12/2012
Location: New Zealand
Posts: 2428

Posted: 01:38am 25 Mar 2016

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this one has slightly less fancy LED displays, but analog control of both voltage and current, and a serial output to log voltage and current with an attached PC:
http://www.ebay.com/itm/272097473122

it could be mounted in a box with a nice 10 turn panel-mounted pot for voltage, standard pot for current, and your ex-laptop brick psu in the back.

cheers,
rob :-)

Grogster

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Posted: 02:23am 25 Mar 2016

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How about the best of both worlds?

Mick's LCD on different PCB with V and A adjustments

A little more expensive, yes, but that would be the one I would go for.

On-board USB sockets too, so you can easily use it for any USB thing - including the likes of the Micromites.

Smoke makes things work. When the smoke gets out, it stops!

robert.rozee
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Posted: 02:41am 25 Mar 2016

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yes, i saw that one, but the price wasn't right

going the other direction, one could go for one of these:
http://www.ebay.com/itm/351617546797
and one of these:
http://www.ebay.com/itm/261912296007
then have a micromite controlling everything and driving an LCD module.

cheers,
rob :-)

panky

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Joined: 02/10/2012
Location: Australia
Posts: 1114

Posted: 05:14pm 25 Mar 2016

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@Rob

Nice find - I have put in a description so when I search in years to come I can find more easily.

Quote
going the other direction, one could go for one of these:
http://www.ebay.com/itm/351617546797 3 - 40VDC in to 1.5 - 35VDC out stepdown
and one of these:
http://www.ebay.com/itm/261912296007 5A current sense using ACS712 hall effect
then have a micromite controlling everything and driving an LCD module.

Cheers, Doug.

... almost all of the Maximites, the MicromMites, the MM Extremes, the ArmMites, the PicoMite and loving it!

Grogster

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Posted: 04:00am 26 Mar 2016

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This is not so cheap(US$22), but as we are talking about PSU modules, this is one I have used before, and it works well:

7A Buck/Boost current-limited PSU module

This one can be fed with a low input voltage - say 12v - and the output can be adjusted anywhere from 1v through to 30v, even with only a 12v input.
Fully adjustable output voltage, under-voltage and current limit.

Here is a video on YT of a guy making a PSU with this module...

Smoke makes things work. When the smoke gets out, it stops!

twofingers

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Joined: 02/06/2014
Location: Germany
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Posted: 04:22am 26 Mar 2016

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Thanks Grogster!

Grogster said This is not so cheap(US$22), but as we are talking about PSU modules, this is one I have used before, and it works well:

This one looks very similar (~US$14). There are more ... just look for LTC3780.

Regards
Michael

causality ≠ correlation ≠ coincidence

Grogster

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Posted: 09:29pm 26 Mar 2016

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Danke. Ja, das ist die...same.

Sorry can't remember German for 'same' - need to practise my German.

I'm just a beginner, so only know a few words at this stage.
(translation for others: 'Thank you. Yes, this is the...same')

That one is a good price - better then my link, so that would be a pretty good one to go for I would think.

Gr��e.

Smoke makes things work. When the smoke gets out, it stops!

robert.rozee
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Posted: 12:40am 27 Mar 2016

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i've always thought that what is needed is THREE displays:
1. output voltage (v)
2. output current (mA)
3. maximum current (mA)

you'd have a 10 turn pot for adjusting output voltage (1.) connected directly to the buck-converter. the output current display (2.) would be exactly that, no adjustment control needed, but the current reading would be available to a micro.

the maximum current display (3.) would be generated by a small micro (micromite or arduino nano). the micro would have a rotary encoder input to adjust the setting of maximum current. also a switch to select between modes: 'overload trip' and 'limit current'.

when 'limit current' is selected, the PSU would act as expected, throttling back the buck converter until the output current (2.) is no more than the maximum current (3.). this would be most suitable for charging batteries.

when 'overload trip' is selected, the PSU shuts down if the output current (2.) ever exceeds the maximum current (3.) and remains shut down until manually reset. this mode is specifically for protecting an attached circuit.

one major change in usage is that one does not need to short the output of the PSU in order to set the current limits.

an interesting concept?

cheers,
rob :-)

twofingers

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Posted: 04:56am 27 Mar 2016

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@Grogster,@all:
happy Easter/frohe Ostern!

I like the internationality of this forum.

Michael

causality ≠ correlation ≠ coincidence

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