EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: SharpEars on November 24, 2015, 03:03:27 pm
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It seems like any variable voltage/variable current power supply these days is very wide, very deep, very heavy and very loud.
Aren't there any small adjustable voltage/current supplies with passive cooling that provide a meager voltage/current output but also use very little desk space. I am looking for a small one that I can put on my computer desk. 0-10 V is fine and I don't need more than 250 mA, although more would be welcome if it comes in a small package.
With all of the switching regulators available these days, it's hard to believe no manufacturer has created a boxed up unit that is small and light. I mean seriously, I could stock up on a buck converter and a panel meter and build a tiny variable supply powered by a wall wart that takes almost no desk space. There has to be something already pre-fabbed that meets this description - I can't believe I am the first person to think of this.
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http://www.ebay.com/sch/i.html?_nkw=CPS-3205 (http://www.ebay.com/sch/i.html?_nkw=CPS-3205)
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http://www.ebay.com/sch/i.html?_nkw=CPS-3205 (http://www.ebay.com/sch/i.html?_nkw=CPS-3205)
Smaller! ..., and with front outputs for convenience.
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Smaller! ..., and with front outputs for convenience.
I guess there's no pleasing some people! :-//
http://www.ebay.com/itm/141812241288 (http://www.ebay.com/itm/141812241288)
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It seems like any variable voltage/variable current power supply these days is very wide, very deep, very heavy and very loud.
Aren't there any small adjustable voltage/current supplies with passive cooling that provide a meager voltage/current output but also use very little desk space. I am looking for a small one that I can put on my computer desk. 0-10 V is fine and I don't need more than 250 mA, although more would be welcome if it comes in a small package.
With all of the switching regulators available these days, it's hard to believe no manufacturer has created a boxed up unit that is small and light. I mean seriously, I could stock up on a buck converter and a panel meter and build a tiny variable supply powered by a wall wart that takes almost no desk space. There has to be something already pre-fabbed that meets this description - I can't believe I am the first person to think of this.
Most people like big testgear (to a certain point). I know I do (and have friends that do to) because bigger gear (usualy) has bigger screens and buttons to mash.
And most of them aren't exactly load... The high power ones are, and often the tiny ones are too because they don't have room for the big heatsinks, being tiny and all) and need whiny (smaller fans tend to whine harder due to turbulence magic afaik) fans.
If the one in the ebay link is already too small... I think you are better of building your own
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Smaller! ..., and with front outputs for convenience.
I guess there's no pleasing some people! :-//
http://www.ebay.com/itm/141812241288 (http://www.ebay.com/itm/141812241288)
Well, that is smaller! But where is the nice voltage/current display and current adjustment knob, not to mention case :) . :box:
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Philips made a series of cutie supplies. E.g. PE 1509 (30 V / 400 mA). They all have the same case, about 70 mm wide, maybe 120 mm tall and at most 200 mm deep.
HP made many similarly small power supplies with almost any combination of voltage / current up to a few hundred volts. The smallest ones have ~10 W output power and are so small, that there weren't really space for a IEC plug at the rear; the mains cable is fixed...
They also made some in the system 2(?) case (think HP 3400A), e.g. the 6226A/B.
Other P/Ns:
721A
6234A, 6235A
6216A, 6217A, 6218A
and many more
There are many Chinese models of "slim line lab supplies" available, but I think most are switchers, so not really an option...
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Maybe BK Instruments 1550? I have it - UI is little bit stupid (rotary encoders instead buttons, current limit can be read only with shorted outputs) but it is small and very light (it is switching mode supply). And what is most important there are no voltage peaks when load is rapidly changing.
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There are many Chinese models of "slim line lab supplies" available, but I think most are switchers, so not really an option...
If they have post regulators I don't see why not. I have homeplug on my mains, my linear power supply isn't getting anything cleaner to work with than a switcher post regulator.
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http://www.tme.eu/en/details/nsp-3630/one-channel-power-supplies/manson/ (http://www.tme.eu/en/details/nsp-3630/one-channel-power-supplies/manson/)
Pluses:
-small
-lightweight (2kg), easy to grab and move by using a single hand
-no fan (noiseless)
-solid metal chassis
-big display, easy to read from various angles
-quite cheap, around 130$
Minuses:
-one channel only
-output voltage is relatively noisy
-no USB/LAN connection
I have one and I'm happy with it.
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http://www.ebay.com/itm/141812241288 (http://www.ebay.com/itm/141812241288)
Well, that is smaller! But where is the nice voltage/current display and current adjustment knob, not to mention case :) . :box:
Do I have to do everything around here?
http://www.ebay.com/itm/181863444001 (http://www.ebay.com/itm/181863444001)
http://www.ebay.com/itm/400982197535 (http://www.ebay.com/itm/400982197535)
http://www.ebay.com/itm/151876252952 (http://www.ebay.com/itm/151876252952)
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With some patience, these small HPs can be found on the 'bay, typically (again with some patience) in the $30-$60 range. They're 5-1/4"w x 8"d x 3-1/4"h (133 x 368 x 83mm), and weigh about 4-1/2 lb each.
The 6216A is 0-25V @ 0-400mA; the 6218A is 0-50V @ 0-200mA; and the 6212A is 0-100V @ 0-100mA. There is also a 0-10V one, but I don't have one of those. All are constant voltage/constant current supplies, with coarse and fine adjustments for each. The downside is that with only 1 meter (switchable), you can only read one parameter at a time. Other than that. they're solid, silent little buggers.
-Pat
(https://pmanning.smugmug.com/Electronics/Misc-test-equipment/i-MpBtGfj/0/L/IMG_2597-L.jpg)
(https://pmanning.smugmug.com/Electronics/Misc-test-equipment/i-39Wmm69/0/L/IMG_2596-L.jpg)
(https://pmanning.smugmug.com/Electronics/Misc-test-equipment/i-Jcc6LtS/0/L/IMG_2598-L.jpg)
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With some patience, these small HPs can be found on the 'bay, typically (again with some patience) in the $30-$60 range. They're 5-1/4"w x 8"d x 3-1/4"h (133 x 368 x 83mm), and weigh about 4-1/2 lb each.
Cute :) looks like the ones we used at school.
...but much bigger then the one I posted, which was still far too big for Mr. Fussy-Pants OP
...and if something the size of a paperback book is too big, then... :-//
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These are my favourite:
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/ (https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/)
You just can't break them. :-+
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With some patience, these small HPs can be found on the 'bay, typically (again with some patience) in the $30-$60 range. They're 5-1/4"w x 8"d x 3-1/4"h (133 x 368 x 83mm), and weigh about 4-1/2 lb each.
Cute :) looks like the ones we used at school.
...but much bigger then the one I posted, which was still far too big for Mr. Fussy-Pants OP
...and if something the size of a paperback book is too big, then... :-//
:-//
I like 'em (obviously, looking at the pile of them) - they're small, quiet, have current limit and stack. Not to mention well made. ;D
-Pat
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I like 'em
I can tell. ;)
The only thing that worries me is the accuracy of the voltage display/setting. It doesn't look easy to dial exactly (eg.) 3.3V without using an external multimeter.
Edit: I just noticed they aren't all the same. There's one that only goes to 30V on the scale, that one might not be too bad.
There's a few on eBay right now for about $60 but shipping something that heavy to Spain would destroy me. :(
they're small, quiet, have current limit and stack.
Mine, too.
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I like 'em (obviously, looking at the pile of them) - they're small, quiet, have current limit and stack. Not to mention well made. ;D
Kind of makes you wonder why someone hasn't made a knock off of these, instead of building the same old junk over and over like they do.
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There are many Chinese models of "slim line lab supplies" available, but I think most are switchers, so not really an option...
Why not? HP has many lab switchers which pack a big punch in a relatively small and lightweight box. Small Chinese ones can be found but may be less well filtered so less suitable for very sensitive circuits but perfectly suitable for powering many other devices.
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I like 'em (obviously, looking at the pile of them) - they're small, quiet, have current limit and stack. Not to mention well made. ;D
Kind of makes you wonder why someone hasn't made a knock off of these, instead of building the same old junk over and over like they do.
I'm guessing from the weight that they have a huge-ass transformer in them. Nobody makes those transformers cheaply any more. Not cheap enough to compete with the switch-modes anyway.
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These are my favourite:
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/ (https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/)
You just can't break them. :-+
Do they have an output enable switch or just a big honking on/off button?
(I mean, can you see the displays and make adjustments then they're "off"?)
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These are my favourite:
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/ (https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/)
You just can't break them. :-+
Do they have an output enable switch or just a big honking on/off button?
(I mean, can you see the displays and make adjustments then they're "off"?)
No.
Read the thread.....NO over or undershoot.
Ask nctnico, he got one based on what he read in the thread.
I'll say this; for all low current use at any voltage, the fan will never turn on. :-+
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These are my favourite:
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/ (https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/)
You just can't break them. :-+
Do they have an output enable switch or just a big honking on/off button?
(I mean, can you see the displays and make adjustments then they're "off"?)
Be sure to read the entire thread because these small PSUs certainly have issues (including ones with safety). I wouldn't recommend them unless they are rebuild properly to good safety standards.
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can you see the displays and make adjustments then they're "off"?
No.
Bummer.
Still, I guess it's easy enough to put a switch in your wires. Just nice to have one on the PSU though.
Read the thread.....NO over or undershoot.
That wasn't the question :P
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I'm guessing from the weight that they have a huge-ass transformer in them. Nobody makes those transformers cheaply any more. Not cheap enough to compete with the switch-modes anyway.
If you check on ebay you'll find plenty. Just look for a new (buy it now), variable, bench type power supply. Most of what you'll find under $100 will be cheap linear supplies with transformers.
http://www.ebay.com/sch/DC-Power-Supplies-/58288/i.html?LH_ItemCondition=1000&_nkw=variable+power+supply&_sop=15 (http://www.ebay.com/sch/DC-Power-Supplies-/58288/i.html?LH_ItemCondition=1000&_nkw=variable+power+supply&_sop=15)
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Be sure to read the entire thread because these small PSUs certainly have issues (including ones with safety). I wouldn't recommend them unless they are rebuild properly to good safety standards.
Looks like there's dozens of manufacturers as well. That's never good when buying Chinese products - you don't know what you're getting.
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I'm guessing from the weight that they have a huge-ass transformer in them. Nobody makes those transformers cheaply any more. Not cheap enough to compete with the switch-modes anyway.
If you check on ebay you'll find plenty. Just look for a new (buy it now), variable, bench type power supply. Most of what you'll find under $100 will be cheap linear supplies with transformers.
http://www.ebay.com/sch/DC-Power-Supplies-/58288/i.html?LH_ItemCondition=1000&_nkw=variable+power+supply&_sop=15 (http://www.ebay.com/sch/DC-Power-Supplies-/58288/i.html?LH_ItemCondition=1000&_nkw=variable+power+supply&_sop=15)
I'd be tempted to buy one of those modules with an LED display, add a proper potentiometer with knob, put it in a nice case and power it from a switched mode 2A 24VDC wall wart.
http://www.ebay.com/itm/DC-DC-Blue-High-Efficiency-Variable-Power-Supply-Kit-With-Voltage-Display-2A-Out-/290866921083?hash=item43b904fe7b:g:d8sAAMXQhuVRJFpC (http://www.ebay.com/itm/DC-DC-Blue-High-Efficiency-Variable-Power-Supply-Kit-With-Voltage-Display-2A-Out-/290866921083?hash=item43b904fe7b:g:d8sAAMXQhuVRJFpC)
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Here's another for your consideration. It's linear:
http://www.mpja.com/0-18VDC-0-3-A-Variable-Benchtop-Power-Supply/productinfo/29600%20PS/ (http://www.mpja.com/0-18VDC-0-3-A-Variable-Benchtop-Power-Supply/productinfo/29600%20PS/)
I've been tempted to pick one up, but haven't yet, so I can't vouch for the output or build quality.
They also have some switchers like this one:
http://www.mpja.com/0-30VDC-0-3A-Variable-Benchtop-Power-Supply/productinfo/29616%20PS/ (http://www.mpja.com/0-30VDC-0-3A-Variable-Benchtop-Power-Supply/productinfo/29616%20PS/)
It has a fine adjust knob which is nice. The ripple spec is not so great, but that's probably under full load, so it depends what you want to use it for.
They have a bunch in the tall style. Here's the list:
http://www.mpja.com/Benchtop-Power-Supplies/products/2/ (http://www.mpja.com/Benchtop-Power-Supplies/products/2/)
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I'd be tempted to buy one of those modules with an LED display, add a proper potentiometer with knob, put it in a nice case and power it from a switched mode 2A 24VDC wall wart.
http://www.ebay.com/itm/DC-DC-Blue-High-Efficiency-Variable-Power-Supply-Kit-With-Voltage-Display-2A-Out-/290866921083?hash=item43b904fe7b:g:d8sAAMXQhuVRJFpC (http://www.ebay.com/itm/DC-DC-Blue-High-Efficiency-Variable-Power-Supply-Kit-With-Voltage-Display-2A-Out-/290866921083?hash=item43b904fe7b:g:d8sAAMXQhuVRJFpC)
Get one with volts/amps display and current limiting. They don't cost much more...
I've got one of these somewhere: http://www.ebay.com/itm/391036308115 (http://www.ebay.com/itm/391036308115)
It works well enough for that price. It would be a lot better with some proper pots on it instead of fiddly trimmers.
(Edit: In fact it costs half as much as the one you linked to :-DD )
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Another thread recently mentioned the modules like this one. Button control over both voltage setting and current limit, digital display selectable between voltage and current.
http://www.ebay.com/itm/Digital-controlled-Constant-Current-Voltage-DC-Step-Down-LED-Driver-Module-/151864371948?hash=item235bd26aec:g:150AAOSwl9BWL4Q6 (http://www.ebay.com/itm/Digital-controlled-Constant-Current-Voltage-DC-Step-Down-LED-Driver-Module-/151864371948?hash=item235bd26aec:g:150AAOSwl9BWL4Q6)
This is a 3-amp one; there are others with different magnetics that can go up to 10 amps.
EDIT: Here's the other thread. Post #33 includes a video review of the 40V 3A module. Post 35 shows another module that would be more of a snap-in solution. https://www.eevblog.com/forum/beginners/what-do-you-think-about-these-very-inexpensive-benchtop-power-supplies/ (https://www.eevblog.com/forum/beginners/what-do-you-think-about-these-very-inexpensive-benchtop-power-supplies/).
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blackdog built his own into a tiny cisco enclosure, schematics and everything available:
https://www.eevblog.com/forum/chat/show-your-favorite-and-mostly-used-benchtop-psu/msg194801/#msg194801 (https://www.eevblog.com/forum/chat/show-your-favorite-and-mostly-used-benchtop-psu/msg194801/#msg194801)
and there's this one in, what looks like, a 1U enclosure:
https://www.eevblog.com/forum/chat/show-your-favorite-and-mostly-used-benchtop-psu/msg223863/#msg223863 (https://www.eevblog.com/forum/chat/show-your-favorite-and-mostly-used-benchtop-psu/msg223863/#msg223863)
A number of other alternatives in that same (very nice) thread, started by BravoV.
--deckert