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Power supply

ArchiverArchiver Posts: 46,084
edited 2004-06-25 14:03 in General Discussion
I am designing a stamp driven data logging system that must operate for four
days on battery power. I have estimated that the system will draw 150mA. Is
there a viable way to power this unit for this period of time. Solar cells
are NOT a viable solution. Any reasonable suggestion would be appreciated.

I would appreciate a CC response to my e-mail address.

TIA
__________________________________________

Victor Fraenckel vfraenc1@n...
Home of the WindReader Electronic Theodolite
Read the WIND

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-05-04 03:18
    Victor:

    You need a 15A-hr battery.

    Joseph F. Mibelli



    Victorf wrote:

    > I am designing a stamp driven data logging system that must operate for four
    > days on battery power. I have estimated that the system will draw 150mA. Is
    > there a viable way to power this unit for this period of time. Solar cells
    > are NOT a viable solution. Any reasonable suggestion would be appreciated.
    >
    > I would appreciate a CC response to my e-mail address.
    >
    > TIA
    > __________________________________________
    >
    > Victor Fraenckel vfraenc1@n...
    > Home of the WindReader Electronic Theodolite
    > Read the WIND
  • ArchiverArchiver Posts: 46,084
    edited 2000-05-04 06:28
    At 09:08 PM 5/3/00 -0400, Victorf promulgated:
    >I am designing a stamp driven data logging system that must operate for four
    >days on battery power. I have estimated that the system will draw 150mA. Is
    >there a viable way to power this unit for this period of time. Solar cells
    >are NOT a viable solution. Any reasonable suggestion would be appreciated.
    >
    >I would appreciate a CC response to my e-mail address.
    Victor -

    If those are the only constraints, use a gel cel or sealed lead acid battery.
    If size, cost, weight or other factors are important, those need to be stated
    as well.

    Bruce

    >
    >TIA
    >__________________________________________
    >
    >Victor Fraenckel vfraenc1@n...
    >Home of the WindReader Electronic Theodolite
    > Read the WIND
    >
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-30 06:33
    Good evening,

    In a BS2 application, I have a 9V 500mA (unreg.) adaptor
    feeding a 5V regulator. I have the expected two stabalizing caps on the
    regulator.

    After about 2-10 minutes, the system--all logic loads, save
    one inductive load<100mA--shuts down. After a brief unplugging, I find
    the system works again. The logic/regulators are properly protected from
    the inductive load.
    Now: The open-circuit potential of the adaptor is 11.5V. When the
    system shuts off, with the regulator still connected to load, I read 12.7V
    from the adaptor.

    How is this possible?

    I am guessing the adaptor is malfunctioning (an older model from
    several years); I would try another but have none available for a
    few days. The stamp works fine otherwise.

    Thank you for your time,
    Paul
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-30 20:09
    Paul:
    Is the regulator overheating? If so, it goes into thermal self-protection
    mode where it may cycle on/off, ("burp mode"), which produces a pulsed load
    on the power source. If this happens, the transient response of the adapter
    may have voltage overshoots which are confusing your voltmeter. If you look
    at input voltage to the regulator with a scope, the answer may be apparent.

    Ray McArthur

    From: Paul J. Csonka <csonka@e...>
    To: <basicstamps@egroups.com>
    Sent: Monday, October 30, 2000 1:33 AM
    Subject: [noparse][[/noparse]basicstamps] Power Supply
    >
    > In a BS2 application, I have a 9V 500mA (unreg.) adaptor
    > feeding a 5V regulator. I have the expected two stabalizing caps on the
    > regulator.
    >
    > After about 2-10 minutes, the system--all logic loads, save
    > one inductive load<100mA--shuts down. After a brief unplugging, I find
    > the system works again. The logic/regulators are properly protected from
    > the inductive load.
    > Now: The open-circuit potential of the adaptor is 11.5V. When the
    > system shuts off, with the regulator still connected to load, I read 12.7V
    > from the adaptor.
    >
    > How is this possible?
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-30 20:14
    Hi Ray,

    The current from the regulator is well below its capacity, (1/3),
    and I don't believe it's overheating. But it may be in such a way that I
    can't tell...

    I was looking at the potential with a scope to be sure; haven't
    tried yet with a meter. So I believe the measurement is correct.
    There seems to be a clear jump to 12.7V, no decay curves or
    oscillations, etc.

    Thanks for your help,
    Paul


    On Mon, 30 Oct 2000, Ray McArthur wrote:

    > Paul:
    > Is the regulator overheating? If so, it goes into thermal self-protection
    > mode where it may cycle on/off, ("burp mode"), which produces a pulsed load
    > on the power source. If this happens, the transient response of the adapter
    > may have voltage overshoots which are confusing your voltmeter. If you look
    > at input voltage to the regulator with a scope, the answer may be apparent.
    >
    > Ray McArthur
    >
    > From: Paul J. Csonka <csonka@e...>
    > To: <basicstamps@egroups.com>
    > Sent: Monday, October 30, 2000 1:33 AM
    > Subject: [noparse][[/noparse]basicstamps] Power Supply
    > >
    > > In a BS2 application, I have a 9V 500mA (unreg.) adaptor
    > > feeding a 5V regulator. I have the expected two stabalizing caps on the
    > > regulator.
    > >
    > > After about 2-10 minutes, the system--all logic loads, save
    > > one inductive load<100mA--shuts down. After a brief unplugging, I find
    > > the system works again. The logic/regulators are properly protected from
    > > the inductive load.
    > > Now: The open-circuit potential of the adaptor is 11.5V. When the
    > > system shuts off, with the regulator still connected to load, I read 12.7V
    > > from the adaptor.
    > >
    > > How is this possible?
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-30 20:30
    Hi Paul,

    At one time we tested some TO-220 12 volt regulators in the overload mode.
    In order to get them into shutdown, they had to get much too hot to hold
    onto....so your regulators probably are not shutting down. Maybe your
    theory about a defective adapter is correct?

    Ray McArthur

    Original Message
    From: Paul J. Csonka <csonka@e...>
    To: <basicstamps@egroups.com>
    Sent: Monday, October 30, 2000 3:14 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Power Supply


    > Hi Ray,
    >
    > The current from the regulator is well below its capacity, (1/3),
    > and I don't believe it's overheating. But it may be in such a way that I
    > can't tell...
    >
    > I was looking at the potential with a scope to be sure; haven't
    > tried yet with a meter. So I believe the measurement is correct.
    > There seems to be a clear jump to 12.7V, no decay curves or
    > oscillations, etc.
    >
    > Thanks for your help
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-30 20:39
    Hi Ray,

    Could be the adaptor is ruined...(?), as you suggest.

    But I have to say, this would be a rare occurance!

    I get my lab supply back tomorrow, I will try with that. Until
    then, the stamp gets a long nap.

    Thank you for your help,
    Paul



    On Mon, 30 Oct 2000, Ray McArthur wrote:

    > Hi Paul,
    >
    > At one time we tested some TO-220 12 volt regulators in the overload mode.
    > In order to get them into shutdown, they had to get much too hot to hold
    > onto....so your regulators probably are not shutting down. Maybe your
    > theory about a defective adapter is correct?
    >
    > Ray McArthur
    >
    >
    Original Message
    > From: Paul J. Csonka <csonka@e...>
    > To: <basicstamps@egroups.com>
    > Sent: Monday, October 30, 2000 3:14 PM
    > Subject: Re: [noparse][[/noparse]basicstamps] Power Supply
    >
    >
    > > Hi Ray,
    > >
    > > The current from the regulator is well below its capacity, (1/3),
    > > and I don't believe it's overheating. But it may be in such a way that I
    > > can't tell...
    > >
    > > I was looking at the potential with a scope to be sure; haven't
    > > tried yet with a meter. So I believe the measurement is correct.
    > > There seems to be a clear jump to 12.7V, no decay curves or
    > > oscillations, etc.
    > >
    > > Thanks for your help
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-31 02:15
    At 10:33 PM 10/29/00 -0800, Paul J. Csonka wrote:

    >Good evening,
    >
    > In a BS2 application, I have a 9V 500mA (unreg.) adaptor
    >feeding a 5V regulator. I have the expected two stabalizing caps on the
    >regulator.
    >
    > After about 2-10 minutes, the system--all logic loads, save
    >one inductive load<100mA--shuts down. After a brief unplugging, I find
    >the system works again. The logic/regulators are properly protected from
    >the inductive load.
    > Now: The open-circuit potential of the adaptor is 11.5V. When the
    >system shuts off, with the regulator still connected to load, I read 12.7V
    >from the adaptor.
    >
    > How is this possible?

    I think that you will find that the regulator is shutting down, or a bad
    connection somewhere is opening. The clue is that the open circuit voltage
    is so high. I don't see how the adapter could be the problem since it *IS*
    putting out voltage (even though it is higher than you expect).

    Measure the voltage into and coming out of the regulator. Look for bad
    connections.

    dwayne



    Dwayne Reid <dwayner@p...>
    Trinity Electronics Systems Ltd Edmonton, AB, CANADA
    (780) 489-3199 voice (780) 487-6397 fax

    Celebrating 16 years of Engineering Innovation (1984 - 2000)

    * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
    Do NOT send unsolicited commercial email to this email address.
    This message neither grants consent to receive unsolicited
    commercial email nor is intended to solicit commercial email.
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-31 05:31
    Hi Dwayne:

    On Mon, 30 Oct 2000, Dwayne Reid wrote:

    > At 10:33 PM 10/29/00 -0800, Paul J. Csonka wrote:
    >
    > >Good evening,
    > >
    > > In a BS2 application, I have a 9V 500mA (unreg.) adaptor
    > >feeding a 5V regulator. I have the expected two stabalizing caps on the
    > >regulator.
    > >
    > > After about 2-10 minutes, the system--all logic loads, save
    > >one inductive load<100mA--shuts down. After a brief unplugging, I find
    > >the system works again. The logic/regulators are properly protected from
    > >the inductive load.
    > > Now: The open-circuit potential of the adaptor is 11.5V. When the
    > >system shuts off, with the regulator still connected to load, I read 12.7V
    > >from the adaptor.
    > >
    > > How is this possible?
    >
    > I think that you will find that the regulator is shutting down, or a bad
    > connection somewhere is opening. The clue is that the open circuit voltage
    > is so high.

    Perhaps I am misunderstanding you; normal open circuit voltage is
    11.3V measured with a scope.
    When the system fails (shuts off), the adaptor is still connected
    to load, and the scope reads 12.7V. This is higher than O.C., so I wonder
    how this happens or is even possible.



    > I don't see how the adapter could be the problem since it *IS*
    > putting out voltage (even though it is higher than you expect).

    ...sorry, maybe I didn't mention that the current drops to near
    zero.

    I will consider what you say, that the adaptor is not faulty.
    Thank you for your help,
    Paul

    (this should now probably go off-list, as it is off topic)

    >
    > Measure the voltage into and coming out of the regulator. Look for bad
    > connections.
    >
    > dwayne
    >
    >
    >
    > Dwayne Reid <dwayner@p...>
    > Trinity Electronics Systems Ltd Edmonton, AB, CANADA
    > (780) 489-3199 voice (780) 487-6397 fax
    >
    > Celebrating 16 years of Engineering Innovation (1984 - 2000)
    >
    > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
    > Do NOT send unsolicited commercial email to this email address.
    > This message neither grants consent to receive unsolicited
    > commercial email nor is intended to solicit commercial email.
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-11-03 04:06
    Greetings,

    I am looking to reduce a power supply to get a small unit.

    There is up to 24 VAC available for this circuit.
    What is needed ia 12VDC and only 12 ma.
    The 12 ma is the max for the circuit so it needs to be limited for
    power at 12ma.

    Any tips or tricks ?

    TIA.

    Dave
  • ArchiverArchiver Posts: 46,084
    edited 2000-11-03 17:15
    You could Rectify the AC with a diode bridge and filter the DC with a couple
    of electrolytic capacitors. use any one of the TO-220 type voltage
    regulators (either fixed or adjustable eg. LM317) to set your desired
    voltage. As for the current limiting, these devices can be set up as
    constant current sources also. Check out National Semiconductor's voltage
    regulator line.



    Jon Enoch,
    PCB Design Engineer,
    Northern Airborne Technology.




    I am looking to reduce a power supply to get a small unit.

    There is up to 24 VAC available for this circuit.
    What is needed ia 12VDC and only 12 ma.
    The 12 ma is the max for the circuit so it needs to be limited for
    power at 12ma.

    Any tips or tricks ?
  • ArchiverArchiver Posts: 46,084
    edited 2001-02-19 05:22
    Hello. I have been working with a Basic STAMP 2 and now am working with a STAMP
    2e chip. When I try to do a basic powerup and serial port connect, this chip is
    detected (serial port setup is ok) but it does not respond, even when I change
    the directive to 2e from 2. It says it is related to the power supply
    connection. When I go back to the STAMP 2 chip, everything is fine. Can anyone
    help? Thanks.

    Greg
    __________________________________________________________________
    Get your own FREE, personal Netscape Webmail account today at
    http://webmail.netscape.com/
  • ArchiverArchiver Posts: 46,084
    edited 2001-09-28 20:48
    Hello,

    In my project, i have several devices that require +5v so I'm using a 7805
    type regulator with a couple of capacitors. Will the stamp run off of +5
    volts from the regulator or does the on board regulator require higher
    voltage to make its own +5 volts? I'm running this off of a battery that
    may change from 9 to 18 volts so I'd rather use the external regulator that
    can handle a higher voltage input. I'm thinking that it would be safer too
    because hooking that little stamp directly to a motorcycle battery makes me
    nervous.

    Also, for polarity protection (in case someone accidentally gets the battery
    polarity wrong), will a diode in line with the battery be sufficient
    protection?

    Thanks,
    Stewart

    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2001-09-28 21:03
    Stewart,

    There are two possible ways to provide power to the Stamp.
    1) An external 7805 type regulator with the output connected to the
    Vdd pin (Pin 21 on the BS2)
    2) Provide 5.5 to 12v (7.5v recommended) to the Vin (pin24 on the
    BS2). In this case the Vdd pin (pin 21) is able to provide a limited
    amount (I do not recall the limit) of current to other devices.

    A diode should be sufficient for polarity protection but don't
    forget that in the forward direction, depending on the current and
    type, you may drop up to 1v across the diode.

    Phil


    --- In basicstamps@y..., Stewart Mayer <stewlist@k...> wrote:
    > Hello,
    >
    > In my project, i have several devices that require +5v so I'm using
    a 7805
    > type regulator with a couple of capacitors. Will the stamp run off
    of +5
    > volts from the regulator or does the on board regulator require
    higher
    > voltage to make its own +5 volts? I'm running this off of a
    battery that
    > may change from 9 to 18 volts so I'd rather use the external
    regulator that
    > can handle a higher voltage input. I'm thinking that it would be
    safer too
    > because hooking that little stamp directly to a motorcycle battery
    makes me
    > nervous.
    >
    > Also, for polarity protection (in case someone accidentally gets
    the battery
    > polarity wrong), will a diode in line with the battery be sufficient
    > protection?
    >
    > Thanks,
    > Stewart
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2001-09-29 05:51
    Thanks for the help phil. Hooking up the 7805 to pin 21 should do the trick


    Stewart

    Original Message

    From: basicstamps@yahoogroups.com
    Date: Friday, September 28, 2001 03:02:17 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Re: Power Supply

    Stewart,

    There are two possible ways to provide power to the Stamp.
    1) An external 7805 type regulator with the output connected to the
    Vdd pin (Pin 21 on the BS2)
    2) Provide 5.5 to 12v (7.5v recommended) to the Vin (pin24 on the
    BS2). In this case the Vdd pin (pin 21) is able to provide a limited
    amount (I do not recall the limit) of current to other devices.

    A diode should be sufficient for polarity protection but don't
    forget that in the forward direction, depending on the current and
    type, you may drop up to 1v across the diode.

    Phil


    --- In basicstamps@y..., Stewart Mayer <stewlist@k...> wrote:
    > Hello,
    >
    > In my project, i have several devices that require +5v so I'm using
    a 7805
    > type regulator with a couple of capacitors. Will the stamp run off
    of +5
    > volts from the regulator or does the on board regulator require
    higher
    > voltage to make its own +5 volts? I'm running this off of a
    battery that
    > may change from 9 to 18 volts so I'd rather use the external
    regulator that
    > can handle a higher voltage input. I'm thinking that it would be
    safer too
    > because hooking that little stamp directly to a motorcycle battery
    makes me
    > nervous.
    >
    > Also, for polarity protection (in case someone accidentally gets
    the battery
    > polarity wrong), will a diode in line with the battery be sufficient
    > protection?
    >
    > Thanks,
    > Stewart
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]


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  • ArchiverArchiver Posts: 46,084
    edited 2004-03-06 15:24
    Hello,
    I want to use a BSII and a dc motor controller chip for a robot that
    I am building. I want to use one battery. Is it possible to split
    the battery(9v) to run the motor and the BSII pins(One Regulated 5.0
    v using a 7805 regulator). My project is to build a standard robot
    platform and then add pcb cards for such things as IR Module ect.. I
    then want to port to the sx microcontroller. I have built a test
    circuit and when I measure the voltage while the motor is running I
    get about 3.0 v. I don't want to interfer with the BSII.

    Thnaks,
    Curtis
  • ArchiverArchiver Posts: 46,084
    edited 2004-03-06 15:41
    Curtis,

    3V will not power the Stamp. However, you can do as you describe IF the
    battery can provide the voltage/current. So you may want to consider a
    different battery.

    Jonathan

    www.madlabs.info


    Original Message
    From: "cenlasoft" <cenlasoft@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Saturday, March 06, 2004 7:24 AM
    Subject: [noparse][[/noparse]basicstamps] Power Supply


    > Hello,
    > I want to use a BSII and a dc motor controller chip for a robot that
    > I am building. I want to use one battery. Is it possible to split
    > the battery(9v) to run the motor and the BSII pins(One Regulated 5.0
    > v using a 7805 regulator). My project is to build a standard robot
    > platform and then add pcb cards for such things as IR Module ect.. I
    > then want to port to the sx microcontroller. I have built a test
    > circuit and when I measure the voltage while the motor is running I
    > get about 3.0 v. I don't want to interfer with the BSII.
    >
    > Thnaks,
    > Curtis
    >
    >
    >
    >
    > 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.
    >
    > Yahoo! Groups Links
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2004-03-08 12:22
    Principally it is possible to use a single power source for the
    motors and the logic.
    But I would prefer a separate power supply (battery and regulator)
    with a common ground for the stamp and the motors. Motors are a
    source of glitches which can/will interfere with the digital control
    circuitry. Besides that, the motors may require a different voltage.

    Regards
    Adrian
  • ArchiverArchiver Posts: 46,084
    edited 2004-03-08 20:40
    Put a capacitor right across any dc motor. A 1 uF or more. I made a system
    that ran a 12 Volt motor, and the 12 Volts went through a 5 Volt three
    terminal regulator. Got enough glitches to cause the stamp to reset at a
    high rate of speed. Placing back to back zener diodes across the motor,
    rated slightly more than 12 Volts, and the capacitor both at the motor and
    at the board end driving the motor made all the problems go away.

    If you are using the same Voltage for motor and stamp, then an inductor
    between the stamp and the supply, with capacitance on both sides of the
    inductor, as a low pass filter, might help.

    Note that it wasn't a stamp problem, but a system noise problem.

    Original Message
    From: Adrian Schneider [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=yxrlWdlNdxLQN_XJk_99ArPPE_gYJDI1jmeGzZ7ATW4jLgSGdDlC8sUb-pJ1mK0MK7gEJGXYhmvv1QEbL6f65fOkk2U]adrian.schneider@t...[/url
    Sent: Monday, March 08, 2004 7:23 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Re: Power Supply


    Principally it is possible to use a single power source for the motors and
    the logic. But I would prefer a separate power supply (battery and
    regulator) with a common ground for the stamp and the motors. Motors are a
    source of glitches which can/will interfere with the digital control
    circuitry. Besides that, the motors may require a different voltage.

    Regards
    Adrian



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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-23 20:34
    Erik and All,

    Before I place my order for the OEM BSII's, can you tell me if the
    12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or not? I need
    one or two, and if they are regulated, I'd like buy them from Parallax and
    include them in the order too.

    Thanks,

    Tim Medema



    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-23 21:06
    I confirmed with our technical support that it's unregulated. As a
    matter of fact, we don't carry any regulated power supplies.

    Erik Wood
    Parallax, Inc.


    Original Message
    From: Timothy Medema [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=cLuLDNXKntLfNSxKPHZm0bws3ZSqyLh5b-SnxI6ylzYy9QoZtxjKhbKDs2U9Xn--zxbvDW1PwFop50bP]timm@c...[/url
    Sent: Wednesday, June 23, 2004 12:34 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Power Supply


    Erik and All,

    Before I place my order for the OEM BSII's, can you tell me if
    the
    12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or not? I
    need
    one or two, and if they are regulated, I'd like buy them from Parallax
    and
    include them in the order too.

    Thanks,

    Tim Medema



    [noparse][[/noparse]Non-text portions of this message have been removed]



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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-23 21:17
    Thanks for checking that out and letting us know.

    Tim


    At 01:06 PM 6/23/2004, you wrote:
    >I confirmed with our technical support that it's unregulated. As a
    >matter of fact, we don't carry any regulated power supplies.
    >
    >Erik Wood
    >Parallax, Inc.
    >
    >
    >
    Original Message
    >From: Timothy Medema [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=qJ-zeUmdBCFfkyFYe0YtaDTRT6rIW6YEx2_H4QvyhozmI_xcVoDKLrMzwM1sHr4g60kSq0jJfTiE5KVsV3Ol6g]timm@c...[/url
    >Sent: Wednesday, June 23, 2004 12:34 PM
    >To: basicstamps@yahoogroups.com
    >Subject: [noparse][[/noparse]basicstamps] Power Supply
    >
    >
    >Erik and All,
    >
    > Before I place my order for the OEM BSII's, can you tell me if
    >the
    >12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or not? I
    >need
    >one or two, and if they are regulated, I'd like buy them from Parallax
    >and
    >include them in the order too.
    >
    >Thanks,
    >
    >Tim Medema
    >
    >
    >
    >[noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    >
    >To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    >from the same email address that you subscribed. Text in the Subject
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    >Yahoo! Groups Links
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-23 21:55
    So, when you say they are 'unregulated', I then
    assume they contain a small transformer with a
    half-wave or full-wave regulator, and MAYBE an
    output capacitor to reduce the ripple a little.

    Thus they DO output DC which is suitable for
    input into a 7805 or 3904-5 linear regulator.

    Actually having the regulator built-in to the
    wall-wart seems to have limited usefulness for
    the increase in price.

    I guess I don't understand Timothy's reluctance
    to buy 'unregulated' versus 'regulated' wall-warts.

    --- In basicstamps@yahoogroups.com, "Erik Wood" <ewood@p...> wrote:
    > I confirmed with our technical support that it's unregulated. As a
    > matter of fact, we don't carry any regulated power supplies.
    >
    > Erik Wood
    > Parallax, Inc.
    >
    >
    >
    Original Message
    > From: Timothy Medema [noparse][[/noparse]mailto:timm@c...]
    > Sent: Wednesday, June 23, 2004 12:34 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Power Supply
    >
    >
    > Erik and All,
    >
    > Before I place my order for the OEM BSII's, can you tell
    me if
    > the
    > 12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or not?
    I
    > need
    > one or two, and if they are regulated, I'd like buy them from
    Parallax
    > and
    > include them in the order too.
    >
    > Thanks,
    >
    > Tim Medema
    >
    >
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    >
    > 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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    > Yahoo! Groups Links
    >
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    > abuse@p...
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-24 17:14
    Wall wart power supplies are made cheaply. So, they are rated, for example,
    at 12 Volts at one Amp. This means that when they are fully loaded at 1
    Amp, that they put out nominally 12 Volts. But if you don't draw one Amp,
    the Voltage goes up, a lot. I have seen as high as 16-17 Volts unloaded.

    Original Message
    From: Allan Lane [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=sM6JnihwehLmrISpHm_jPBvhWW8ZUWp5cXyfc_BCMyOTc-TGL_HcKgSqbn1Exe11yyjGpAWi5RPgrBykUrfawCUk6Q]allan.lane@h...[/url
    Sent: Wednesday, June 23, 2004 4:55 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Re: Power Supply


    So, when you say they are 'unregulated', I then
    assume they contain a small transformer with a
    half-wave or full-wave regulator, and MAYBE an
    output capacitor to reduce the ripple a little.

    Thus they DO output DC which is suitable for
    input into a 7805 or 3904-5 linear regulator.

    Actually having the regulator built-in to the
    wall-wart seems to have limited usefulness for
    the increase in price.

    I guess I don't understand Timothy's reluctance
    to buy 'unregulated' versus 'regulated' wall-warts.

    --- In basicstamps@yahoogroups.com, "Erik Wood" <ewood@p...> wrote:
    > I confirmed with our technical support that it's unregulated. As a
    > matter of fact, we don't carry any regulated power supplies.
    >
    > Erik Wood
    > Parallax, Inc.
    >
    >
    >
    Original Message
    > From: Timothy Medema [noparse][[/noparse]mailto:timm@c...]
    > Sent: Wednesday, June 23, 2004 12:34 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Power Supply
    >
    >
    > Erik and All,
    >
    > Before I place my order for the OEM BSII's, can you tell
    me if
    > the
    > 12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or not?
    I
    > need
    > one or two, and if they are regulated, I'd like buy them from
    Parallax
    > and
    > include them in the order too.
    >
    > Thanks,
    >
    > Tim Medema
    >
    >
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    >
    > 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.
    >
    > Yahoo! Groups Links
    >
    >
    >
    >
    >
    >
    >
    > This message has been scanned by WebShield. Please report SPAM to
    > abuse@p...




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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-24 17:42
    Hi Allan,

    I'm not really reluctant to buy an unregulated wall-wart, it's
    much more that I'm cheap and lazy. If the wall-wart is regulated, it saves
    me the time of including a regulator in the project, and usually a
    mass-produced regulated wall-wart is less expensive than building the
    regulator separately myself. Like I said, it's more that I'm cheap and
    lazy, that's all.

    Tim Medema


    At 01:55 PM 6/23/2004, you wrote:
    >So, when you say they are 'unregulated', I then
    >assume they contain a small transformer with a
    >half-wave or full-wave regulator, and MAYBE an
    >output capacitor to reduce the ripple a little.
    >
    >Thus they DO output DC which is suitable for
    >input into a 7805 or 3904-5 linear regulator.
    >
    >Actually having the regulator built-in to the
    >wall-wart seems to have limited usefulness for
    >the increase in price.
    >
    >I guess I don't understand Timothy's reluctance
    >to buy 'unregulated' versus 'regulated' wall-warts.
    >
    >--- In basicstamps@yahoogroups.com, "Erik Wood" <ewood@p...> wrote:
    > > I confirmed with our technical support that it's unregulated. As a
    > > matter of fact, we don't carry any regulated power supplies.
    > >
    > > Erik Wood
    > > Parallax, Inc.
    > >
    > >
    > >
    Original Message
    > > From: Timothy Medema [noparse][[/noparse]mailto:timm@c...]
    > > Sent: Wednesday, June 23, 2004 12:34 PM
    > > To: basicstamps@yahoogroups.com
    > > Subject: [noparse][[/noparse]basicstamps] Power Supply
    > >
    > >
    > > Erik and All,
    > >
    > > Before I place my order for the OEM BSII's, can you tell
    >me if
    > > the
    > > 12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or not?
    >I
    > > need
    > > one or two, and if they are regulated, I'd like buy them from
    >Parallax
    > > and
    > > include them in the order too.
    > >
    > > Thanks,
    > >
    > > Tim Medema
    > >
    > >
    > >
    > > [noparse][[/noparse]Non-text portions of this message have been removed]
    > >
    > >
    > >
    > > 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.
    > >
    > > Yahoo! Groups Links
    > >
    > >
    > >
    > >
    > >
    > >
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    > > This message has been scanned by WebShield. Please report SPAM to
    > > abuse@p...
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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-24 17:46
    Thanks!

    --- In basicstamps@yahoogroups.com, Timothy Medema <timm@c...> wrote:
    >
    > Hi Allan,
    >
    > I'm not really reluctant to buy an unregulated wall-wart,
    it's
    > much more that I'm cheap and lazy. If the wall-wart is regulated,
    it saves
    > me the time of including a regulator in the project, and usually a
    > mass-produced regulated wall-wart is less expensive than building
    the
    > regulator separately myself. Like I said, it's more that I'm cheap
    and
    > lazy, that's all.
    >
    > Tim Medema
    >
    >
    > At 01:55 PM 6/23/2004, you wrote:
    > >So, when you say they are 'unregulated', I then
    > >assume they contain a small transformer with a
    > >half-wave or full-wave regulator, and MAYBE an
    > >output capacitor to reduce the ripple a little.
    > >
    > >Thus they DO output DC which is suitable for
    > >input into a 7805 or 3904-5 linear regulator.
    > >
    > >Actually having the regulator built-in to the
    > >wall-wart seems to have limited usefulness for
    > >the increase in price.
    > >
    > >I guess I don't understand Timothy's reluctance
    > >to buy 'unregulated' versus 'regulated' wall-warts.
    > >
    > >--- In basicstamps@yahoogroups.com, "Erik Wood" <ewood@p...> wrote:
    > > > I confirmed with our technical support that it's unregulated.
    As a
    > > > matter of fact, we don't carry any regulated power supplies.
    > > >
    > > > Erik Wood
    > > > Parallax, Inc.
    > > >
    > > >
    > > >
    Original Message
    > > > From: Timothy Medema [noparse][[/noparse]mailto:timm@c...]
    > > > Sent: Wednesday, June 23, 2004 12:34 PM
    > > > To: basicstamps@yahoogroups.com
    > > > Subject: [noparse][[/noparse]basicstamps] Power Supply
    > > >
    > > >
    > > > Erik and All,
    > > >
    > > > Before I place my order for the OEM BSII's, can you
    tell
    > >me if
    > > > the
    > > > 12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or
    not?
    > >I
    > > > need
    > > > one or two, and if they are regulated, I'd like buy them from
    > >Parallax
    > > > and
    > > > include them in the order too.
    > > >
    > > > Thanks,
    > > >
    > > > Tim Medema
    > > >
    > > >
    > > >
    > > > [noparse][[/noparse]Non-text portions of this message have been removed]
    > > >
    > > >
    > > >
    > > > 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.
    > > >
    > > > Yahoo! Groups Links
    > > >
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    > > >
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    > > >
    > > >
    > > >
    > > > This message has been scanned by WebShield. Please report SPAM
    to
    > > > abuse@p...
    > >
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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-25 01:31
    I have to agree with Allan on this one. It is good design practice to use "local regulation", where the voltage regulator is as close as possible to the device(s) to be powered. The main reason for this is to reduce the susceptibility of the circuit to high frequency noise. Such noise can be hard to detect, and will drive a Stamp crazy.

    Dave

    Timothy Medema <timm@c...> wrote:

    Hi Allan,

    I'm not really reluctant to buy an unregulated wall-wart, it's
    much more that I'm cheap and lazy. If the wall-wart is regulated, it saves
    me the time of including a regulator in the project, and usually a
    mass-produced regulated wall-wart is less expensive than building the
    regulator separately myself. Like I said, it's more that I'm cheap and
    lazy, that's all.

    Tim Medema


    At 01:55 PM 6/23/2004, you wrote:
    >So, when you say they are 'unregulated', I then
    >assume they contain a small transformer with a
    >half-wave or full-wave regulator, and MAYBE an
    >output capacitor to reduce the ripple a little.
    >
    >Thus they DO output DC which is suitable for
    >input into a 7805 or 3904-5 linear regulator.
    >
    >Actually having the regulator built-in to the
    >wall-wart seems to have limited usefulness for
    >the increase in price.
    >
    >I guess I don't understand Timothy's reluctance
    >to buy 'unregulated' versus 'regulated' wall-warts.
    >
    >--- In basicstamps@yahoogroups.com, "Erik Wood" wrote:
    > > I confirmed with our technical support that it's unregulated. As a
    > > matter of fact, we don't carry any regulated power supplies.
    > >
    > > Erik Wood
    > > Parallax, Inc.
    > >
    > >
    > >
    Original Message
    > > From: Timothy Medema [noparse][[/noparse]mailto:timm@c...]
    > > Sent: Wednesday, June 23, 2004 12:34 PM
    > > To: basicstamps@yahoogroups.com
    > > Subject: [noparse][[/noparse]basicstamps] Power Supply
    > >
    > >
    > > Erik and All,
    > >
    > > Before I place my order for the OEM BSII's, can you tell
    >me if
    > > the
    > > 12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or not?
    >I
    > > need
    > > one or two, and if they are regulated, I'd like buy them from
    >Parallax
    > > and
    > > include them in the order too.
    > >
    > > Thanks,
    > >
    > > Tim Medema
    > >
    > >
    > >
    > > [noparse][[/noparse]Non-text portions of this message have been removed]
    > >
    > >
    > >
    > > 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.
    > >
    > > Yahoo! Groups Links
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > > This message has been scanned by WebShield. Please report SPAM to
    > > abuse@p...
    >
    >
    >
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-25 13:56
    Hi Dave,

    Good advice. I'd also agree that it is good design practice to
    use "local regulation". When I use a regulated wall-warts, I always add a
    lot of filtering at the project end for the very reasons you mentioned.

    Tim


    At 05:31 PM 6/24/2004, you wrote:
    >I have to agree with Allan on this one. It is good design practice to use
    >"local regulation", where the voltage regulator is as close as possible to
    >the device(s) to be powered. The main reason for this is to reduce the
    >susceptibility of the circuit to high frequency noise. Such noise can be
    >hard to detect, and will drive a Stamp crazy.
    >
    >Dave
    >
    >Timothy Medema <timm@c...> wrote:
    >
    >Hi Allan,
    >
    >I'm not really reluctant to buy an unregulated wall-wart, it's
    >much more that I'm cheap and lazy. If the wall-wart is regulated, it saves
    >me the time of including a regulator in the project, and usually a
    >mass-produced regulated wall-wart is less expensive than building the
    >regulator separately myself. Like I said, it's more that I'm cheap and
    >lazy, that's all.
    >
    >Tim Medema
    >
    >
    >At 01:55 PM 6/23/2004, you wrote:
    > >So, when you say they are 'unregulated', I then
    > >assume they contain a small transformer with a
    > >half-wave or full-wave regulator, and MAYBE an
    > >output capacitor to reduce the ripple a little.
    > >
    > >Thus they DO output DC which is suitable for
    > >input into a 7805 or 3904-5 linear regulator.
    > >
    > >Actually having the regulator built-in to the
    > >wall-wart seems to have limited usefulness for
    > >the increase in price.
    > >
    > >I guess I don't understand Timothy's reluctance
    > >to buy 'unregulated' versus 'regulated' wall-warts.
    > >
    > >--- In basicstamps@yahoogroups.com, "Erik Wood" wrote:
    > > > I confirmed with our technical support that it's unregulated. As a
    > > > matter of fact, we don't carry any regulated power supplies.
    > > >
    > > > Erik Wood
    > > > Parallax, Inc.
    > > >
    > > >
    > > >
    Original Message
    > > > From: Timothy Medema [noparse][[/noparse]mailto:timm@c...]
    > > > Sent: Wednesday, June 23, 2004 12:34 PM
    > > > To: basicstamps@yahoogroups.com
    > > > Subject: [noparse][[/noparse]basicstamps] Power Supply
    > > >
    > > >
    > > > Erik and All,
    > > >
    > > > Before I place my order for the OEM BSII's, can you tell
    > >me if
    > > > the
    > > > 12 VDC/1 Amp Power Supply, Stock#: 750-00007, is regulated or not?
    > >I
    > > > need
    > > > one or two, and if they are regulated, I'd like buy them from
    > >Parallax
    > > > and
    > > > include them in the order too.
    > > >
    > > > Thanks,
    > > >
    > > > Tim Medema
    > > >
    > > >
    > > >
    > > > [noparse][[/noparse]Non-text portions of this message have been removed]
    > > >
    > > >
    > > >
    > > > 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.
    > > >
    > > > Yahoo! Groups Links
    > > >
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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-25 14:03
    --- In basicstamps@yahoogroups.com, Timothy Medema <timm@c...> wrote:
    >
    > Hi Dave,
    >
    > Good advice. I'd also agree that it is good design
    practice to
    > use "local regulation". When I use a regulated wall-warts, I
    always add a
    > lot of filtering at the project end for the very reasons you
    mentioned.
    >
    > Tim

    Local filtering is a good idea if you are doing any switching as that
    can create spikes.

    also if you are doing any ADC inputs as the power supply is often the
    reference for the ADC chip.

    and if you are doing PWM as the high speed may create unwanted noise
    on the line.

    Dave
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