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(off topic) Benchtop power supply — Parallax Forums

(off topic) Benchtop power supply

ArchiverArchiver Posts: 46,084
edited 2003-05-12 15:27 in General Discussion
(Sorry for the dumb question, but I don't want to waste $200!)

When they speak of series and parallel output options, I understand that
means you can double the output current or output voltage. So can I power
my circuit off of one output at 5 volts, and power the steppers off of
another output at 12 volts without frying anything?

Thanks in advance,

-John



>Dual output is cool for op-amp work, just be sure you can turn the voltage
>all the way down and that the power supplies can be tied together. One with
>a +5 and +/- 12 would be even better.
>
>
Original Message
>
>
> > Can anyone suggest a good bench top power supply and where to get it? I'm
> > starting to play with stepper motors, and my wall warts just aren't
>cutting
> > it. I'm tired of trying to find just the right one with enough capacity
>for
> > what I'm driving.
> > I'm not allergic to spending a couple of hundred dollars, just as long as
> > it is a good one.
> >
> > Dual outputs? Adjustable? Anything I left out?
>
>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>
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Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-05-12 01:13
    Typically a power supply with dual outputs will allow you to tie the grounds
    together so you can tie your 5-volt Stamp and 12-volt motor circuits
    together.

    The current limiting on the variable outputs is probably the best feature --
    this can keep you out of trouble if you short something goofing around.

    Original Message

    > (Sorry for the dumb question, but I don't want to waste $200!)
    >
    > When they speak of series and parallel output options, I understand that
    > means you can double the output current or output voltage. So can I power
    > my circuit off of one output at 5 volts, and power the steppers off of
    > another output at 12 volts without frying anything?
    >
    > Thanks in advance,
    >
    > -John
    >
    >
    >
    > >Dual output is cool for op-amp work, just be sure you can turn the
    voltage
    > >all the way down and that the power supplies can be tied together. One
    with
    > >a +5 and +/- 12 would be even better.
    > >
    > >
    Original Message
    > >
    > >
    > > > Can anyone suggest a good bench top power supply and where to get it?
    I'm
    > > > starting to play with stepper motors, and my wall warts just aren't
    > >cutting
    > > > it. I'm tired of trying to find just the right one with enough
    capacity
    > >for
    > > > what I'm driving.
    > > > I'm not allergic to spending a couple of hundred dollars, just as long
    as
    > > > it is a good one.
    > > >
    > > > Dual outputs? Adjustable? Anything I left out?
  • ArchiverArchiver Posts: 46,084
    edited 2003-05-12 01:22
    Nuts & Volts has a vendors links page on their web site -- might look in the
    test equipment section. Here is one example:

    http://www.web-tronics.com/30serdigrobe.html


    Here are the advertisers links:

    http://www.nutsvolts.com/adlinks.htm


    Original Message

    > Typically a power supply with dual outputs will allow you to tie the
    grounds
    > together so you can tie your 5-volt Stamp and 12-volt motor circuits
    > together.
    >
    > The current limiting on the variable outputs is probably the best
    feature --
    > this can keep you out of trouble if you short something goofing around.
    >
    >
    Original Message
    >
    > > (Sorry for the dumb question, but I don't want to waste $200!)
    > >
    > > When they speak of series and parallel output options, I understand that
    > > means you can double the output current or output voltage. So can I
    power
    > > my circuit off of one output at 5 volts, and power the steppers off of
    > > another output at 12 volts without frying anything?
    > >
    > > Thanks in advance,
    > >
    > > -John
    > >
    > >
    > >
    > > >Dual output is cool for op-amp work, just be sure you can turn the
    > voltage
    > > >all the way down and that the power supplies can be tied together. One
    > with
    > > >a +5 and +/- 12 would be even better.
    > > >
    > > >
    Original Message
    > > >
    > > >
    > > > > Can anyone suggest a good bench top power supply and where to get
    it?
    > I'm
    > > > > starting to play with stepper motors, and my wall warts just aren't
    > > >cutting
    > > > > it. I'm tired of trying to find just the right one with enough
    > capacity
    > > >for
    > > > > what I'm driving.
    > > > > I'm not allergic to spending a couple of hundred dollars, just as
    long
    > as
    > > > > it is a good one.
    > > > >
    > > > > Dual outputs? Adjustable? Anything I left out?
    >
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-05-12 02:37
    You can also use separate 5-volt Stamp and 12-volt motor supplies if you
    tie the grounds together. Two vendors that I use for power supplies are
    www.jameco.com and www.allelectronics.com .

    Dennis

    Original Message
    From: Rodent [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rtr_S6GljZKJBjDmfA0vqANlRvc26m1tms3rgmPfZSnYcM8QFdGphckrVAqfBV8Nwa1mqWp4WKy2U6c]daweasel@s...[/url
    Sent: Sunday, May 11, 2003 5:13 PM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] (off topic) Benchtop power supply


    Typically a power supply with dual outputs will allow you to tie the
    grounds together so you can tie your 5-volt Stamp and 12-volt motor
    circuits together.

    The current limiting on the variable outputs is probably the best
    feature -- this can keep you out of trouble if you short something
    goofing around.

    Original Message

    > (Sorry for the dumb question, but I don't want to waste $200!)
    >
    > When they speak of series and parallel output options, I understand
    > that means you can double the output current or output voltage. So
    > can I power my circuit off of one output at 5 volts, and power the
    > steppers off of another output at 12 volts without frying anything?
    >
    > Thanks in advance,
    >
    > -John
    >
    >
    >
    > >Dual output is cool for op-amp work, just be sure you can turn the
    voltage
    > >all the way down and that the power supplies can be tied together.
    > >One
    with
    > >a +5 and +/- 12 would be even better.
    > >
    > >
    Original Message
    > >
    > >
    > > > Can anyone suggest a good bench top power supply and where to get
    > > > it?
    I'm
    > > > starting to play with stepper motors, and my wall warts just
    > > > aren't
    > >cutting
    > > > it. I'm tired of trying to find just the right one with enough
    capacity
    > >for
    > > > what I'm driving.
    > > > I'm not allergic to spending a couple of hundred dollars, just as
    > > > long
    as
    > > > it is a good one.
    > > >
    > > > Dual outputs? Adjustable? Anything I left out?




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  • ArchiverArchiver Posts: 46,084
    edited 2003-05-12 03:24
    One last question, and I promise I'll stop.

    I'm finding very few of the power supplies offer negative voltage. Being
    I'm a electronics noobie, what would I need negative voltage for? I've
    seen you guys talk about some LCD's requiring a negative voltage, but other
    than that, would I be shorting myself if I didn't have negative voltage? I
    always attempt to buy for the future, so the next project doesn't send me
    back to the store [noparse]:)[/noparse]

    Thanks in advance,

    -John
  • ArchiverArchiver Posts: 46,084
    edited 2003-05-12 03:38
    Except for the LCD and some op-amp IC's, you will probably never need a
    negative supply. However, if the power supplies have a removable jumper that
    connects chassis ground to the negative output terminal, you should be able
    to tie them together to get a +/- supply. Some of the high-end units offer
    this as a feature -- essentially you put the two supplies in series and your
    ground point is referenced on the positive terminal of the negative supply
    and the negative terminal of the positive supply. Like having a center-tap
    on a set of batteries.

    Like I mentioned, a 0-30 volt 2-3 amp supply with meters or displays is
    ideal, and the adjustable current limiting is the second best feature. If
    you can find one with +5 and +12 or +/- 12 then you would be set.

    Original Message

    > One last question, and I promise I'll stop.
    >
    > I'm finding very few of the power supplies offer negative voltage. Being
    > I'm a electronics noobie, what would I need negative voltage for? I've
    > seen you guys talk about some LCD's requiring a negative voltage, but
    other
    > than that, would I be shorting myself if I didn't have negative voltage?
    I
    > always attempt to buy for the future, so the next project doesn't send me
    > back to the store [noparse]:)[/noparse]
  • ArchiverArchiver Posts: 46,084
    edited 2003-05-12 03:43
    The first thing that pops into my head is you ever build something that uses
    a 741 Op amp. While it's one of the older Op amps on the market, it still
    has a lot of life in it. But... you have to feed it with both a positive and
    negative voltage.

    I haven't read the other replys yet, but have you thought about building a
    power supply? You can get a good book on power supply projects from Radio
    Shack. So not only will you get a ps, you'll learn about one of the most
    basic items needed by both the electronics dude and the circuit. Plus you'll
    be able to fix the thing if it ever needs it.

    Tom
    kf4yyd

    Original Message
    From: John Walton [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=_vTkstPbjpg87webq0t2R5iYR0gOobr9PJ_4fXFY_9_CJj-4Qb0ESE3l7V57Y0zxxnAW2AXOnNg5]john@l...[/url
    Sent: Sunday, May 11, 2003 10:24 PM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] (off topic) Benchtop power supply


    One last question, and I promise I'll stop.

    I'm finding very few of the power supplies offer negative voltage. Being
    I'm a electronics noobie, what would I need negative voltage for? I've
    seen you guys talk about some LCD's requiring a negative voltage, but other
    than that, would I be shorting myself if I didn't have negative voltage? I
    always attempt to buy for the future, so the next project doesn't send me
    back to the store [noparse]:)[/noparse]

    Thanks in advance,

    -John



    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
    from the same email address that you subscribed. Text in the Subject and
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  • ArchiverArchiver Posts: 46,084
    edited 2003-05-12 15:27
    If you are doing analog circuits using op-amps, it's
    nice to have a negative voltage, so you can get
    a negative swing to your output.

    RS-232 uses -12 volts for its drivers -- which
    people don't use much, as the MAX232 chips
    generate their own -12 volts.

    Some really old (1978) IC's used three voltages
    (-5, +5 and +12).

    Many bench supplies offer multiple voltages, and
    they are constructed so that you can configure
    negative voltages simply by using the proper
    connections to 'Ground'. I believe these are
    called 'floating' supplies.

    --- In basicstamps@yahoogroups.com, John Walton <john@l...> wrote:
    > One last question, and I promise I'll stop.
    >
    > I'm finding very few of the power supplies offer negative voltage.
    Being
    > I'm a electronics noobie, what would I need negative voltage for?
    I've
    > seen you guys talk about some LCD's requiring a negative voltage,
    but other
    > than that, would I be shorting myself if I didn't have negative
    voltage? I
    > always attempt to buy for the future, so the next project doesn't
    send me
    > back to the store [noparse]:)[/noparse]
    >
    > Thanks in advance,
    >
    > -John
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