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Power Usage — Parallax Forums

Power Usage

ArchiverArchiver Posts: 46,084
edited 2001-05-23 16:12 in General Discussion
Hi everyone

I am not new to electronics, but have never really grasped the concept of
power usage of a circuits.
I have a mobile platform controlled by a Stamp2sx with various other modules
on board (eg 2x stepper controllers, ultrasonic, radio modem ect.).
I run each one of a single 9v Dry cell since none of them consume more than
about 100mA.
But this is now where I get lost. I want to run all of them from one power
source. I have lots of rechargeble cellpacks with 2400mAh rating, but I am
worried if I use them I will put too much current through the circuits. In
other words, if my stamp uses 60mA and I connect it to a 2400 source, will
it damage it?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2001-05-22 18:26
    The circuits are just going to take what they need.

    Original Message
    From: "Okkie Vermeulen" <okkie@i...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, May 22, 2001 12:21 PM
    Subject: [noparse][[/noparse]basicstamps] Power Usage


    > Hi everyone
    >
    > I am not new to electronics, but have never really grasped the concept of
    > power usage of a circuits.
    > I have a mobile platform controlled by a Stamp2sx with various other
    modules
    > on board (eg 2x stepper controllers, ultrasonic, radio modem ect.).
    > I run each one of a single 9v Dry cell since none of them consume more
    than
    > about 100mA.
    > But this is now where I get lost. I want to run all of them from one power
    > source. I have lots of rechargeble cellpacks with 2400mAh rating, but I am
    > worried if I use them I will put too much current through the circuits. In
    > other words, if my stamp uses 60mA and I connect it to a 2400 source, will
    > it damage it?
    >
    >
    >
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2001-05-22 18:32
    Sorry hit the send before I was finished. No It shouldn't damage your stamp
    as long as you don't try and sink more than 30 ma through any one I/O pin or
    exceed 100 ma for your total power consumption if your using the external 5
    volt regulator.
    Original Message
    From: "Okkie Vermeulen" <okkie@i...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, May 22, 2001 12:21 PM
    Subject: [noparse][[/noparse]basicstamps] Power Usage


    > Hi everyone
    >
    > I am not new to electronics, but have never really grasped the concept of
    > power usage of a circuits.
    > I have a mobile platform controlled by a Stamp2sx with various other
    modules
    > on board (eg 2x stepper controllers, ultrasonic, radio modem ect.).
    > I run each one of a single 9v Dry cell since none of them consume more
    than
    > about 100mA.
    > But this is now where I get lost. I want to run all of them from one power
    > source. I have lots of rechargeble cellpacks with 2400mAh rating, but I am
    > worried if I use them I will put too much current through the circuits. In
    > other words, if my stamp uses 60mA and I connect it to a 2400 source, will
    > it damage it?
    >
    >
    >
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2001-05-22 21:06
    What about the +5V on the stamp, how much can it handle?


    Original Message
    From: Ricky Konvicka [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=oboITP7EdxCKviWZOozdNq0nJ17sJ_JLgpfrI-hX9YHQzv2h7ylh75MaICwM5y5KcXqt1XfxIwYuATGL_6tpzg]ricky@m...[/url
    Sent: 22 May 2001 18:32
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Power Usage


    Sorry hit the send before I was finished. No It shouldn't damage your stamp
    as long as you don't try and sink more than 30 ma through any one I/O pin or
    exceed 100 ma for your total power consumption if your using the external 5
    volt regulator.
    Original Message
    From: "Okkie Vermeulen" <okkie@i...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, May 22, 2001 12:21 PM
    Subject: [noparse][[/noparse]basicstamps] Power Usage


    > Hi everyone
    >
    > I am not new to electronics, but have never really grasped the concept of
    > power usage of a circuits.
    > I have a mobile platform controlled by a Stamp2sx with various other
    modules
    > on board (eg 2x stepper controllers, ultrasonic, radio modem ect.).
    > I run each one of a single 9v Dry cell since none of them consume more
    than
    > about 100mA.
    > But this is now where I get lost. I want to run all of them from one power
    > source. I have lots of rechargeble cellpacks with 2400mAh rating, but I am
    > worried if I use them I will put too much current through the circuits. In
    > other words, if my stamp uses 60mA and I connect it to a 2400 source, will
    > it damage it?
    >
    >
    >
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >




    Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
  • ArchiverArchiver Posts: 46,084
    edited 2001-05-22 21:48
    The 5 volt on the stamp will source or sink no more than 75 ma total (all 16
    I/O pins).
    Original Message
    From: "Okkie Vermeulen" <okkie@i...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, May 22, 2001 3:06 PM
    Subject: RE: [noparse][[/noparse]basicstamps] Power Usage


    > What about the +5V on the stamp, how much can it handle?
    >
    >
    >
    Original Message
    > From: Ricky Konvicka [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=kkMbU5ctK3UIHERj8mk5LHn_LHcTgyqsapiDf7Fg5ym6oodEcN5M2XWKLalCbHrFOpDBULC1lw6MY8yxiCqsQMXXobPH]ricky@m...[/url
    > Sent: 22 May 2001 18:32
    > To: basicstamps@yahoogroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] Power Usage
    >
    >
    > Sorry hit the send before I was finished. No It shouldn't damage your
    stamp
    > as long as you don't try and sink more than 30 ma through any one I/O pin
    or
    > exceed 100 ma for your total power consumption if your using the external
    5
    > volt regulator.
    >
    Original Message
    > From: "Okkie Vermeulen" <okkie@i...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Tuesday, May 22, 2001 12:21 PM
    > Subject: [noparse][[/noparse]basicstamps] Power Usage
    >
    >
    > > Hi everyone
    > >
    > > I am not new to electronics, but have never really grasped the concept
    of
    > > power usage of a circuits.
    > > I have a mobile platform controlled by a Stamp2sx with various other
    > modules
    > > on board (eg 2x stepper controllers, ultrasonic, radio modem ect.).
    > > I run each one of a single 9v Dry cell since none of them consume more
    > than
    > > about 100mA.
    > > But this is now where I get lost. I want to run all of them from one
    power
    > > source. I have lots of rechargeble cellpacks with 2400mAh rating, but I
    am
    > > worried if I use them I will put too much current through the circuits.
    In
    > > other words, if my stamp uses 60mA and I connect it to a 2400 source,
    will
    > > it damage it?
    > >
    > >
    > >
    > >
    > >
    > > Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    > >
    > >
    > >
    >
    >
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2001-05-23 00:01
    It doesn't matter how much current is available - the load will only
    take what it needs. The 2400mAH rating only indicates how long the
    battery will last at any given load current.

    It does matter what the source voltage is. You didn't say what voltage
    the 2400mAH pack will provide. This must be no greater than the
    regulators or other circuits can deal with.

    In the case of the Stamp on board regulator, it depends on the
    particular model of Stamp. Some are limited to 15v maximum, others
    higher to 40 volts.

    Another consideration if you are using the on board +5 volt regulated
    output for auxiliary circuits: The higher the input voltage to the
    regulator, the less total current you can use from the +5v regulator
    output because of the power (voltage in minus voltage out times
    current) that must be dissipated in the regulator.

    For example, the BS1-1C regulator is limited to 50mA with a 9v source,
    40mA with a 12v source, 10mA with a 25v source, and 2-3mA with a 40v
    source (page 10 of Basic Stamp Manual v1.8 by Parallax). But if your
    auxiliary circuits are powered directly from the battery (not from the
    Stamp +5v regulator), then those loads don't enter into this
    discussion.

    If you are already powering everything from individual 9 volt
    batteries, then you should have no problem powering them all from a
    single 9 volt higher capacity source.

    Dick Ballard
    ballardr@a...



    On Tue, 22 May 2001 18:21:58 +0100, you wrote:

    >I am not new to electronics, but have never really grasped the concept of
    >power usage of a circuits.
    >I have a mobile platform controlled by a Stamp2sx with various other modules
    >on board (eg 2x stepper controllers, ultrasonic, radio modem ect.).
    >I run each one of a single 9v Dry cell since none of them consume more than
    >about 100mA.
    >But this is now where I get lost. I want to run all of them from one power
    >source. I have lots of rechargeble cellpacks with 2400mAh rating, but I am
    >worried if I use them I will put too much current through the circuits. In
    >other words, if my stamp uses 60mA and I connect it to a 2400 source, will
    >it damage it?
  • ArchiverArchiver Posts: 46,084
    edited 2001-05-23 16:12
    Thanx you guys for the help.

    What I am gonna try to do now is to use make up a NiCD rechargable pack of
    about 9.6V and build a circuit to provide 2 outputs (5V ,9V) and use this
    then to power all the modules. That way I can safeguard the Stamps inbuild
    regulator.




    Original Message
    From: Dick Ballard [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=IllMB04AD-UjL9TXzLeMRq_wj_jeX5D8WQGy296f5O4I_zpOyNhT20pQWBhfP7VV9w0pxmM1pPA]ballardr@a...[/url
    Sent: 23 May 2001 00:02
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Power Usage


    It doesn't matter how much current is available - the load will only
    take what it needs. The 2400mAH rating only indicates how long the
    battery will last at any given load current.

    It does matter what the source voltage is. You didn't say what voltage
    the 2400mAH pack will provide. This must be no greater than the
    regulators or other circuits can deal with.

    In the case of the Stamp on board regulator, it depends on the
    particular model of Stamp. Some are limited to 15v maximum, others
    higher to 40 volts.

    Another consideration if you are using the on board +5 volt regulated
    output for auxiliary circuits: The higher the input voltage to the
    regulator, the less total current you can use from the +5v regulator
    output because of the power (voltage in minus voltage out times
    current) that must be dissipated in the regulator.

    For example, the BS1-1C regulator is limited to 50mA with a 9v source,
    40mA with a 12v source, 10mA with a 25v source, and 2-3mA with a 40v
    source (page 10 of Basic Stamp Manual v1.8 by Parallax). But if your
    auxiliary circuits are powered directly from the battery (not from the
    Stamp +5v regulator), then those loads don't enter into this
    discussion.

    If you are already powering everything from individual 9 volt
    batteries, then you should have no problem powering them all from a
    single 9 volt higher capacity source.

    Dick Ballard
    ballardr@a...



    On Tue, 22 May 2001 18:21:58 +0100, you wrote:

    >I am not new to electronics, but have never really grasped the concept of
    >power usage of a circuits.
    >I have a mobile platform controlled by a Stamp2sx with various other
    modules
    >on board (eg 2x stepper controllers, ultrasonic, radio modem ect.).
    >I run each one of a single 9v Dry cell since none of them consume more than
    >about 100mA.
    >But this is now where I get lost. I want to run all of them from one power
    >source. I have lots of rechargeble cellpacks with 2400mAh rating, but I am
    >worried if I use them I will put too much current through the circuits. In
    >other words, if my stamp uses 60mA and I connect it to a 2400 source, will
    >it damage it?




    Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
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