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Home > Archive > Electrical Engineering > March 2007 > Favorite bench supply circuit?
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Favorite bench supply circuit?
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| Usual Suspect 2007-03-05, 5:25 pm |
| I want to build a bench power supply, and am looking 'round the net for a
good circuit.
Requirements: 2 outputs, adjustable v, adjustable i, v & i meters (or
digits). Prefer 30v max, or similar. Preset v selections (5, 12, 15, etc.)
would be nice.
Here's one I found, complete with the designer's smiling face on each circuit
illustration:
http://members.shaw.ca/roma/supply-4.html
What's your favorite circuit? Features you like that I haven't mentioned?
Thanks,
--
Al, the usual
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| Usual Suspect 2007-03-05, 5:25 pm |
| miso@sushi.com sez:
> ...$20, which is what I pay for bench supplies.
Where?
--
Al, the usual
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| "Usual Suspect" <reply@thegroup.net> wrote in message
news:0001HW.C211B8F802889593F04076C8@news.sf.sbcglobal.net...
>I want to build a bench power supply, and am looking 'round the net for a
> good circuit.
>
> Requirements: 2 outputs, adjustable v, adjustable i, v & i meters (or
> digits). Prefer 30v max, or similar. Preset v selections (5, 12, 15, etc.)
> would be nice.
>
> Here's one I found, complete with the designer's smiling face on each circuit
> illustration:
>
> http://members.shaw.ca/roma/supply-4.html
>
> What's your favorite circuit? Features you like that I haven't mentioned?
>
> Thanks,
> --
> Al, the usual
>
Perhaps you should get a copy of the current issue (March 2007) of Nuts & Volts
magazine. It has a construction article that's just begging for you to look at
it. The article is "A Test Bench Power Supply". The power supply, as
presented, provides two 0-20V @ 1A supplies and one fixed +5V @ 1A supply. Your
other fixed supplies are easily added by using the appropriate power
transformers and regulators. The regulator circuits are trivial.
www.nutsvolts.com
They will send you a free copy to entice you to become a subscriber. (My own
subscription has been ongoing since 1/80)
--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)
Some days you're the dog, some days the hydrant.
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| Dave Plowman (News) 2007-03-05, 8:25 pm |
| In article <0001HW.C211B8F802889593F04076C8@news.sf.sbcglobal.net>,
Usual Suspect <reply@thegroup.net> wrote:
> I want to build a bench power supply, and am looking 'round the net for
> a good circuit.
While not wanting to put you off, unless you already have most of the
major parts it will cost you far more to make than to buy a ready made
one. Such is life these days.
--
*Two wrongs are only the beginning *
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
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| seanacais 2007-03-05, 8:25 pm |
| Here is a simple one for 0-30V @ 3A with current limiting
http://www.electronics-lab.com/proj.../003/index.html
If you read thru the forums you'll find a parts list and updated
schematic that expanded this to dual 0-30 @ 5A complete
with PCB's that can be downloaded.
Further reading will show how to add digital V and A meters.
Good luck
Kevin
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| Rich Grise 2007-03-05, 8:25 pm |
| On Mon, 05 Mar 2007 20:06:49 +0000, Usual Suspect wrote:
> I want to build a bench power supply, and am looking 'round the net for a
> good circuit.
>
> Requirements: 2 outputs, adjustable v, adjustable i, v & i meters (or
> digits). Prefer 30v max, or similar. Preset v selections (5, 12, 15, etc.)
> would be nice.
>
> Here's one I found, complete with the designer's smiling face on each
> circuit illustration:
>
> http://members.shaw.ca/roma/supply-4.html
>
> What's your favorite circuit? Features you like that I haven't mentioned?
>
It looks like a lot of fun, actually. To make it really sexy, you should
check the LM317 data sheet, and modify this one to be adjustable down to
0. :-) A current limit wouldn't hurt, and I guess you can do whatever
metering you want to.
I do kinda like the idea of presets - I even already have a circuit
in mind for n latching circuits for n spst switches. :-)
Have Fun!
Rich
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| TimPerry 2007-03-05, 8:25 pm |
| Usual Suspect wrote:
> I want to build a bench power supply, and am looking 'round the net
> for a good circuit.
>
> Requirements: 2 outputs, adjustable v, adjustable i, v & i meters (or
> digits). Prefer 30v max, or similar. Preset v selections (5, 12, 15,
> etc.) would be nice.
ok as far as it goes but you need to specify a current, line regulation,
load regulation, curent limiting, crowbar protection,
switching or linear, and even line voltage. also voltage range i.e. 0-30
5 - 30 etc.
>
> Here's one I found, complete with the designer's smiling face on each
> circuit illustration:
>
> http://members.shaw.ca/roma/supply-4.html
>
> What's your favorite circuit? Features you like that I haven't
> mentioned?
>
> Thanks,
my favorite? that would be 7 or 8 200w or larger NPN transistors in parallel
with emitter resistors mounted on a huge heatsink driven by another 200 W
transistor powered by a very large transformer into matched 30A bridge
rectifiers.
the main filer cap is a very large "computer" cap (ok, if you are young
think of a "power stiffener" for car audio.)
the voltmeter is a large mirrored scale and "expanded" using switchable
precision zeners. i.e. 0-10, 10-20, 20 -30V
the ammeter is a matching large mirrored scale attached to a high current
meter shunt through a multi-turn calibration pot. the meter has diode
limiters to protect it from surges.
the supply can be driven from an internal or external reference. the
reference source is on a separate winding and is offset several volts below
common so as to achieve a zero volt output. for improved load regulation the
regulator references to the output terminals. voltage is controlled via a
multi-turn pot.
primarily intended for high current applications at 13.8 Vdc this unit was
result after many less robust supplies became shall we say... non
functional.
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| miso@sushi.com 2007-03-06, 3:25 am |
| On Mar 5, 2:16 pm, Usual Suspect <r...@thegroup.net> wrote:
> m...@sushi.com sez:
>
>
> Where?
> --
> Al, the usual
Electronics (ham) swap meets. Any used HP is fine. Some of the Lambda
late model supplies with digital readouts have problems, but the older
gear is good. None of mine have digital displays, but meters are
cheap. I even have one of the HP Harrison supplies, which are stone
age. Speak of the devil:
<http://cgi.ebay.com/HP-HARRISON-620...DC-BENCH-POWER-
SUPPLY_W0QQitemZ330093581220QQihZ014QQcategoryZ58286QQrdZ1QQcmdZViewItem>
This this the Lamba that often has trouble:
<http://cgi.ebay.com/ws/eBayISAPI.dll?
ViewItem&item=330094946204&ssPageName=MERC_VI_RUPX_Pr8_PcY_BID_Stores_IT&refitem=330093581220&itemcount=8&refwidgetloc=active_view_item&usedrule1=UpSell_LogicX&refwidgettype=cross_promot_widget>
Bench supplies are quite heavy. I'd sure hate to buy one on ebay
unless the seller double packs it. Still, I'd get a HP supply from
Ebay before building my own.
Speaking of supplies with digital readouts, I recall a chip I designed
that worked fine with any bench supply except those HP with the
readout. [I'd have to research to find the number.] It turns out HP
put in a nice soft start feature that was so "soft" it found a flaw in
my undervoltage lockout.
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| Esther & Fester Bestertester 2007-03-06, 3:25 am |
| THERES RAJ, BLR sez:
> http://www.electronicsforyou.com
You, sir, are a troll.
The site is nothing but one of those "faux" resource sites that crop up way
too often in Google results stating that they have [fill in whatever terms
you used in your Google search] at the right price. Sites like this must be
simply collecting hits, showing the numbers to potential advertisers, and
collecting $$.
If anybody has any other suggestion as to what purpose these
serious-waste-of-time sites serve, I'd be happy to hear.
FBt
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| N Cook 2007-03-06, 3:25 am |
| Usual Suspect <reply@thegroup.net> wrote in message
news:0001HW.C211B8F802889593F04076C8@news.sf.sbcglobal.net...
> I want to build a bench power supply, and am looking 'round the net for a
> good circuit.
>
> Requirements: 2 outputs, adjustable v, adjustable i, v & i meters (or
> digits). Prefer 30v max, or similar. Preset v selections (5, 12, 15, etc.)
> would be nice.
>
> Here's one I found, complete with the designer's smiling face on each
circuit
> illustration:
>
> http://members.shaw.ca/roma/supply-4.html
>
> What's your favorite circuit? Features you like that I haven't mentioned?
>
> Thanks,
> --
> Al, the usual
>
Assuming your 2 supplies are from isolated secondaries or separate mains
transformers and the outputs will parallel, then series/isolated
pair/parallel switch is easy to add to double volts or current range (single
rail).
If for repair or soak testing then something I would have had a use for is a
presettable current monitor that sounds a sounder if the current drain goes
above or below a settable amount from the initial free, ie below any current
limit , current drain, for instability/thermal/intermittant fault checks
--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
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| cr500r 2007-03-06, 1:25 pm |
| I like this one:
http://www.wikihow.com/Convert-a-Co...ab-Power-Supply
who doesn't have an old PC sitting around?
-Jeff
"Usual Suspect" <reply@thegroup.net> wrote in message
news:0001HW.C211B8F802889593F04076C8@news.sf.sbcglobal.net...
>I want to build a bench power supply, and am looking 'round the net for a
> good circuit.
>
> Requirements: 2 outputs, adjustable v, adjustable i, v & i meters (or
> digits). Prefer 30v max, or similar. Preset v selections (5, 12, 15, etc.)
> would be nice.
>
> Here's one I found, complete with the designer's smiling face on each
> circuit
> illustration:
>
> http://members.shaw.ca/roma/supply-4.html
>
> What's your favorite circuit? Features you like that I haven't mentioned?
>
> Thanks,
> --
> Al, the usual
>
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| cr500r 2007-03-06, 1:25 pm |
| They can be a bit noisy (understatement), but PC supplies are shielded, the
regulation is usually really good, and the amperage is great, as well as the
efficiency compared to linear.
It all depends on how much radiated noise you can accept, you can always
filter the wires coming out of it.
"Usual Suspect" <reply@thegroup.net> wrote in message
news:0001HW.C212E85402CFAF32F01826C8@news.sf.sbcglobal.net...
> cr500r sez:
>
> http://www.wikihow.com/Convert-a-Co...to-a-Lab-Power-
> Supp
>
> Aw, but they're *switchers*. A last resort for a bench supply, imho.
> --
> Al, the usual
>
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| Tzortzakakis Dimitrios 2007-03-07, 1:25 pm |
|
? "Usual Suspect" <reply@thegroup.net> ?????? ??? ??????
news:0001HW.C211B8F802889593F04076C8@news.sf.sbcglobal.net...
> I want to build a bench power supply, and am looking 'round the net for a
> good circuit.
>
> Requirements: 2 outputs, adjustable v, adjustable i, v & i meters (or
> digits). Prefer 30v max, or similar. Preset v selections (5, 12, 15, etc.)
> would be nice.
>
> Here's one I found, complete with the designer's smiling face on each
circuit
> illustration:
>
> http://members.shaw.ca/roma/supply-4.html
>
> What's your favorite circuit? Features you like that I haven't mentioned?
>
I don't know if you find that interesting, but for my thesis in Kozani I
built a high-voltage 1kV 100 mA power supply.220 V/750 V transformer(with a
6.3 V tetriary for the valves' filaments)bridge rectifier with 16 (4*4)
1n4004 (?) diodes with a 100 nF 1kV capacitor and a 1kohm bleeder across
each diode, 3*450 V 100 uF capacitors, again with bleeders, switching on
through the primary.Anything robust enough to stay intact to a little
voltage fluctuation can be virtually supplied with a bridge rectifier and a
large capacitor.
--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
dimtzort AT otenet DOT gr
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| yep, older hp,harrison bricks!
an hp6200b has been my companion for YEARS!
analog meter, basic controls, two plug terminals front, all sorts of useless
terms on the rear too!
stay with a basic type, no frills that will distract u from the task at
hand.
"Usual Suspect" <reply@thegroup.net> wrote in message
news:0001HW.C211B8F802889593F04076C8@news.sf.sbcglobal.net...
> I want to build a bench power supply, and am looking 'round the net for a
> good circuit.
>
> Requirements: 2 outputs, adjustable v, adjustable i, v & i meters (or
> digits). Prefer 30v max, or similar. Preset v selections (5, 12, 15, etc.)
> would be nice.
>
> Here's one I found, complete with the designer's smiling face on each
circuit
> illustration:
>
> http://members.shaw.ca/roma/supply-4.html
>
> What's your favorite circuit? Features you like that I haven't mentioned?
>
> Thanks,
> --
> Al, the usual
>
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