Forums

Benchtop Power Supply Options

Started by Jurd May 7, 2014
Hello again,

It is time for me to acquire a better bench top power solution.  Most of 
the time I will use it to power a breadboard for experimentation.  I 
used a wall wart for awhile until it got super noisy, and batteries are 
a hassle. I was about to go for something like this: 
http://tinyurl.com/qexphfy

And then attach something like this: http://tinyurl.com/qc5e9ma to the 
leads internally.  (and maybe add a power switch, mount it and the 
breadboard all to a piece of melamine board, etc).  I would of course 
verify output with the DVOM before I trusted the display.

For someone still in the larval stage, do you suppose this would be 
adequate?  Will 15V be enough for future growth? So far I've done mostly 
5V logic, 9V guitar stompboxery and small radio.  Occasionally I've done 
some 18V and 24V stuff, though.  I see that a lot of other power supply 
kits say they go up to 30V, but they cost upwards of 4x as much.

Am I being too cheap?  I was going to just buy/dumpsterdive the parts 
and use an online schematic, but I might not know enough to verify a 
schematic before I fry myself and burn the house down.  Therefore I 
think a kit is the way to go- should be correct, comes with all the 
right parts, and (hopefully) has instructions that'll teach me a thing 
or two.

I've looked at a bunch of kits and this Elenco one seems pretty idiot 
proof, but is there anything else you folks might suggest otherwise?

Thanks.

-J
In article <lkeb1e$7kf$1@news.albasani.net>, 
guitardorkspamspameggsandham74@gmail.com says...
> > Hello again, > > It is time for me to acquire a better bench top power solution. Most of > the time I will use it to power a breadboard for experimentation. I > used a wall wart for awhile until it got super noisy, and batteries are > a hassle. I was about to go for something like this: > http://tinyurl.com/qexphfy > > And then attach something like this: http://tinyurl.com/qc5e9ma to the > leads internally. (and maybe add a power switch, mount it and the > breadboard all to a piece of melamine board, etc). I would of course > verify output with the DVOM before I trusted the display. > > For someone still in the larval stage, do you suppose this would be > adequate? Will 15V be enough for future growth? So far I've done mostly > 5V logic, 9V guitar stompboxery and small radio. Occasionally I've done > some 18V and 24V stuff, though. I see that a lot of other power supply > kits say they go up to 30V, but they cost upwards of 4x as much. > > Am I being too cheap? I was going to just buy/dumpsterdive the parts > and use an online schematic, but I might not know enough to verify a > schematic before I fry myself and burn the house down. Therefore I > think a kit is the way to go- should be correct, comes with all the > right parts, and (hopefully) has instructions that'll teach me a thing > or two. > > I've looked at a bunch of kits and this Elenco one seems pretty idiot > proof, but is there anything else you folks might suggest otherwise? > > Thanks. > > -J
0-30V @ 3 AMps, digital display with current limiting controls for 49 bucks. get two if you can so you can generate dual rails, or look at that site and get a dual supply. I always send people here when low cost is in their plan! http://www.circuitspecialists.com/csi3003sm.html Jamie
On Wed, 07 May 2014 17:11:00 -0500, Jurd wrote:

> Hello again, > > It is time for me to acquire a better bench top power solution. Most of > the time I will use it to power a breadboard for experimentation. I > used a wall wart for awhile until it got super noisy, and batteries are > a hassle. I was about to go for something like this: > http://tinyurl.com/qexphfy > > And then attach something like this: http://tinyurl.com/qc5e9ma to the > leads internally. (and maybe add a power switch, mount it and the > breadboard all to a piece of melamine board, etc). I would of course > verify output with the DVOM before I trusted the display. > > For someone still in the larval stage, do you suppose this would be > adequate? Will 15V be enough for future growth? So far I've done mostly > 5V logic, 9V guitar stompboxery and small radio. Occasionally I've done > some 18V and 24V stuff, though. I see that a lot of other power supply > kits say they go up to 30V, but they cost upwards of 4x as much. > > Am I being too cheap? I was going to just buy/dumpsterdive the parts > and use an online schematic, but I might not know enough to verify a > schematic before I fry myself and burn the house down. Therefore I > think a kit is the way to go- should be correct, comes with all the > right parts, and (hopefully) has instructions that'll teach me a thing > or two. > > I've looked at a bunch of kits and this Elenco one seems pretty idiot > proof, but is there anything else you folks might suggest otherwise? > > Thanks. > > -J
Your plan is sound, except that you'll find that the case is much too small for the meter. Look here if you want complete solutions: http://www.mpja.com/Benchtop- Power-Supplies/products/2/. I've found that regardless of whether you're doing a 1-off or production, the box you put the electronics in almost always costs more than the electronics. So you're tossing quite a bit of value along with the box. You can also just use the power supply as-is, and check the voltage with a meter when you need to. That works well for me. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
On Wed, 7 May 2014 18:28:24 -0400, "Maynard A. Philbrook Jr."
<jamie_ka1lpa@charter.net> wrote:

>In article <lkeb1e$7kf$1@news.albasani.net>, >guitardorkspamspameggsandham74@gmail.com says... >> >> Hello again, >> >> It is time for me to acquire a better bench top power solution. Most of >> the time I will use it to power a breadboard for experimentation. I >> used a wall wart for awhile until it got super noisy, and batteries are >> a hassle. I was about to go for something like this: >> http://tinyurl.com/qexphfy >> >> And then attach something like this: http://tinyurl.com/qc5e9ma to the >> leads internally. (and maybe add a power switch, mount it and the >> breadboard all to a piece of melamine board, etc). I would of course >> verify output with the DVOM before I trusted the display. >> >> For someone still in the larval stage, do you suppose this would be >> adequate? Will 15V be enough for future growth? So far I've done mostly >> 5V logic, 9V guitar stompboxery and small radio. Occasionally I've done >> some 18V and 24V stuff, though. I see that a lot of other power supply >> kits say they go up to 30V, but they cost upwards of 4x as much. >> >> Am I being too cheap? I was going to just buy/dumpsterdive the parts >> and use an online schematic, but I might not know enough to verify a >> schematic before I fry myself and burn the house down. Therefore I >> think a kit is the way to go- should be correct, comes with all the >> right parts, and (hopefully) has instructions that'll teach me a thing >> or two. >> >> I've looked at a bunch of kits and this Elenco one seems pretty idiot >> proof, but is there anything else you folks might suggest otherwise? >> >> Thanks. >> >> -J >0-30V @ 3 AMps, digital display with current limiting controls >for 49 bucks. get two if you can so you can generate dual rails, >or look at that site and get a dual supply. > > I always send people here when low cost is in their plan! > >http://www.circuitspecialists.com/csi3003sm.html > >Jamie
This costs a little more, but it's a linear, so will be less noisy. http://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/mastech-regulated-variable-dc-power-supply-hy3003d-30v-3a/prod_2.html I use one. It's very stable. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation
John Larkin <jjlarkin@highnotlandthistechnologypart.com> wrote:
> On Wed, 7 May 2014 18:28:24 -0400, "Maynard A. Philbrook Jr." > <jamie_ka1lpa@charter.net> wrote: >> In article <lkeb1e$7kf$1@news.albasani.net>, >> guitardorkspamspameggsandham74@gmail.com says... >> >>> And then attach something like this: http://tinyurl.com/qc5e9ma to >>> the leads internally.
Some of these little LCD and LED meters can measure their own power supply voltage and some can't. In other words, some of them *require* a 9 V battery to work. It usually says somewhere in the description.
>>> I would of course verify output with the DVOM before I trusted the >>> display.
Good idea.
>>> So far I've done mostly 5V logic, 9V guitar stompboxery and small >>> radio.
If you have any plans to do audio stuff that requires both positive and negative supplies, it might pay to buy a dual-output supply. You can interconnect the two supplies (either with built-in switches or by applying wires to the outputs) and get both positive and negative. On the fancy ones you can just turn one knob to vary both outputs. Don't forget that a "power supply" adjustable in 1.5 V increments is as close as all the AA batteries (and holders) you can scrounge. This is not the right thing for 5 V at 10 A but if you need an odd voltage at low current for a little while, it's hard to get anything simpler.
>>> I was going to just buy/dumpsterdive the parts and use an online >>> schematic, but I might not know enough to verify a schematic before >>> I fry myself and burn the house down.
Use the right size fuse in the AC input, be very meticulous with all the AC (120 V) wiring, and unplug the thing from the wall when you're not using it, and you are unlikely to burn the house down. If it develops a bad fault when you're sitting in front of it, it will usually heat up slowly enough that you can either shut it off and investigate, or (in urgent cases) toss it out the window. General advice: if you buy one, it will probably have a fuse in the AC input. Find out what type and size it is and put a few on your next Digi-Key or Mouser order. You shouldn't blow it too often, but it's a bummer to be out of commission for a 25 cent fuse. (If it keeps blowing and you don't know why, then there is a problem inside the supply. But sometimes you know why, like you accidentally connected that 300 A diesel starter motor to your 3 A supply.) It may or may not have a fuse in the DC output; most don't. Usually, if you try to draw too much current from the output, the voltage automatically drops lower (as low as maybe 1.5 V) to reduce the current.
> This costs a little more, but it's a linear, so will be less noisy. > > http://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/mastech-regulated-variable-dc-power-supply-hy3003d-30v-3a/prod_2.html
That design (or a clone of it) seems very popular. The oval power button and three binding posts are exactly the same on all of them; older ones had LED meters but the newer ones are LCD. I see the same thing sold (for more money) as an "HQ Power PS3003U", and Tektronix even rebadged the older LED-meter version. There is a wider version with dual variable outputs and a fixed 5 V output as well. I have used the Tektronix LED-meter version, plus someone else's clone of the LED-meter version, before, and they both worked well. The meters on someone else's clone were slightly inaccurate, but those specific units had also had several years of exposure to students. Personally, I use an 0-12V/6A, 0-24V/3A supply that I assembled from a kit about 25 years ago. It has served for almost all of the trouble I get into. It was designed by Western Electric engineers and I expect it to outlive me. :) Matt Roberds
On Wednesday, May 7, 2014 6:11:00 PM UTC-4, Jurd wrote:
> Hello again, >=20 >=20 > It is time for me to acquire a better bench top power solution. Most of=
=20
> the time I will use it to power a breadboard for experimentation. I=20 > used a wall wart for awhile until it got super noisy, and batteries are=
=20
> a hassle. I was about to go for something like this:=20 > http://tinyurl.com/qexphfy >=20 > And then attach something like this: http://tinyurl.com/qc5e9ma to the=20 > leads internally. (and maybe add a power switch, mount it and the=20 > breadboard all to a piece of melamine board, etc). I would of course=20 > verify output with the DVOM before I trusted the display. >=20 > For someone still in the larval stage, do you suppose this would be=20 > adequate? Will 15V be enough for future growth? So far I've done mostly=
=20
> 5V logic, 9V guitar stompboxery and small radio. Occasionally I've done=
=20
> some 18V and 24V stuff, though. I see that a lot of other power supply=
=20
> kits say they go up to 30V, but they cost upwards of 4x as much.=20 >=20 > Am I being too cheap? I was going to just buy/dumpsterdive the parts=20 > and use an online schematic, but I might not know enough to verify a=20 > schematic before I fry myself and burn the house down. Therefore I=20 > think a kit is the way to go- should be correct, comes with all the=20 > right parts, and (hopefully) has instructions that'll teach me a thing=20 > or two. >=20 >=20 > I've looked at a bunch of kits and this Elenco one seems pretty idiot=20 > proof, but is there anything else you folks might suggest otherwise?
If you've got more time than money, then I like the idea of building your o= wn power supply. Either from a kit... or better yet (more learning potenti= al) building it yourself from pieces/parts. There are lots of places that = will show you how to make a linear supply. ("Art of Electronics", for one.= )=20 And hey you can draw up a schematic and post it here for comments. If not, I also like the mastech linear supplies that John L. linked to. George H.
>=20 >=20 >=20 > Thanks. >=20 >=20 >=20 > -J
On Thu, 8 May 2014, mroberds@att.net wrote:

> John Larkin <jjlarkin@highnotlandthistechnologypart.com> wrote: >> On Wed, 7 May 2014 18:28:24 -0400, "Maynard A. Philbrook Jr." >> <jamie_ka1lpa@charter.net> wrote: >>> In article <lkeb1e$7kf$1@news.albasani.net>, >>> guitardorkspamspameggsandham74@gmail.com says... >>> >>>> And then attach something like this: http://tinyurl.com/qc5e9ma to >>>> the leads internally. > > Some of these little LCD and LED meters can measure their own power > supply voltage and some can't. In other words, some of them *require* > a 9 V battery to work. It usually says somewhere in the description. >
If not, grab a small transformer out of a clock radio or something and make a little linear power supply for it. The meter won't require much power. I suppose at this point, there are plenty of switching type AC adapters that could be put in a box without taking much space. Michael

"Michael Black" <et472@ncf.ca> wrote in message 
news:alpine.LNX.2.02.1405081039270.10885@darkstar.example.org...
> On Thu, 8 May 2014, mroberds@att.net wrote: > >> John Larkin <jjlarkin@highnotlandthistechnologypart.com> wrote: >>> On Wed, 7 May 2014 18:28:24 -0400, "Maynard A. Philbrook Jr." >>> <jamie_ka1lpa@charter.net> wrote: >>>> In article <lkeb1e$7kf$1@news.albasani.net>, >>>> guitardorkspamspameggsandham74@gmail.com says... >>>> >>>>> And then attach something like this: http://tinyurl.com/qc5e9ma to >>>>> the leads internally. >> >> Some of these little LCD and LED meters can measure their own power >> supply voltage and some can't. In other words, some of them *require* >> a 9 V battery to work. It usually says somewhere in the description. >> > If not, grab a small transformer out of a clock radio or something and > make a little linear power supply for it. The meter won't require much > power. I suppose at this point, there are plenty of switching type AC > adapters that could be put in a box without taking much space.
IIRC - old ethernet cards have a handy switcher transformer, presumably dimensioned for a 5V supply, I think the secondary is about right for 9V or so - that would suit probably most of the commercially available digital display modules.
On Wednesday, May 7, 2014 3:11:00 PM UTC-7, Jurd wrote:
> Hello again, > > > > It is time for me to acquire a better bench top power solution. ...
> I've looked at a bunch of kits and this Elenco one seems pretty idiot > proof, but is there anything else you folks might suggest otherwise?
For fiddling about, you'll want one or more adjustable supplies. If you are comfortable doing the low-voltage parts, it's often suitable to pick up a carcass of some disused appliance, and adapt its supply to your bench (like, get an old PC power supply for gobs of +12 and +5V, or a newer one for those and +3.3). Add indicator lights, at least one for each independent section, or you'll not notice an overload/short circuit and shutdown or fuse-blowing response. Variable voltage is nice, and variable current limit is very useful (like, for charging batteries); consider a time switch, as well (to prevent overcharging batteries). Both voltage-variable and current-limit-variable supplies benefit from a built-in (ALWAYS CONNECTED) meter. Whenever you adjust the knob, you'll want to watch the voltmeter, or (for current limit) you'll want to short the output while watching the ammeter. Watch for sales on inexpensive multimeters... like at HarborFreight. If AC power is important in your experimentation, get a GCFI module, an isolation transformer, and a variac (variable autotransformer).
On 2014-05-08, Ian Field <gangprobing.alien@ntlworld.com> wrote:

> IIRC - old ethernet cards have a handy switcher transformer, presumably > dimensioned for a 5V supply, I think the secondary is about right for 9V or > so - that would suit probably most of the commercially available digital > display modules.
yeah it's a dc-dc converter producing an isolated 9VDC from a 5VDC supply This is used to power the thinnet tranceiver. so look for cards with BNC connectors. -- umop apisdn --- news://freenews.netfront.net/ - complaints: news@netfront.net ---