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lm317 regulator — Parallax Forums

lm317 regulator

ArchiverArchiver Posts: 46,084
edited 2000-07-02 08:11 in General Discussion
I am using lm313 to drive the following
BASIC stamp OEM, lt1298, NE555 Timer, Nand Gate, Frequency to voltage
converter, Interval timer.

I am feeding the the regulator from a nine volt battery and it is producing
5.2 volts. The I.C is getting warm. It is not heat sinked.
Is it normal for the I.C to get warm or is it that some thig is wrong?

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Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-06-30 17:11
    if its only warm - don't worry about it - however I doubt if the 9v battery
    will last very long

    is the lm313 a 5 volt reg - if it is I would worry why it is 5.2v rather
    than 5.02

    richard


    Original Message
    From: fernando hood <hoodey@h...>
    To: <basicstamps@egroups.com>
    Sent: Friday, June 30, 2000 10:56 AM
    Subject: Re: [noparse][[/noparse]basicstamps]lm317 regulator


    >
    > I am using lm313 to drive the following
    > BASIC stamp OEM, lt1298, NE555 Timer, Nand Gate, Frequency to voltage
    > converter, Interval timer.
    >
    > I am feeding the the regulator from a nine volt battery and it is
    producing
    > 5.2 volts. The I.C is getting warm. It is not heat sinked.
    > Is it normal for the I.C to get warm or is it that some thig is wrong?
    >
    > ________________________________________________________________________
    > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-06-30 20:19
    Linear regualtors like 78XX and LM317 will dissipate exceding
    voltage as heat like a simple resistor. It is built-in with temperature
    protection. Difference from input voltage - output voltage will be
    transformed in heat.This is not efficient. The 9 volt battery will
    quickly be empty.
    Switching regulators (DC-DC converters) are more efficient, but more
    complicated and expensive.

    ACJacques


    fernando hood wrote:
    >
    > I am using lm313 to drive the following
    > BASIC stamp OEM, lt1298, NE555 Timer, Nand Gate, Frequency to voltage
    > converter, Interval timer.
    >
    > I am feeding the the regulator from a nine volt battery and it is producing
    > 5.2 volts. The I.C is getting warm. It is not heat sinked.
    > Is it normal for the I.C to get warm or is it that some thig is wrong?
    >
    > ________________________________________________________________________
    > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
  • ArchiverArchiver Posts: 46,084
    edited 2000-06-30 21:24
    I may be mistaken, but isn't the LM317 an adjustable regulator,
    output set by external resistor?
    If so, you can make any voltage you want, up to nearly the Vin.
    Original Message
    From: fernando hood [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=eszEClNdsHlm864sxvdmb97vnxSFkKV4689VxbAjbsl8DbLKApPldTrMz563TarKS1HF2PhNkVhBAFoaTg]hoodey@h...[/url
    Sent: Friday, June 30, 2000 11:57 AM
    To: basicstamps@egroups.com
    Subject: Re: [noparse][[/noparse]basicstamps]lm317 regulator



    I am using lm313 to drive the following
    BASIC stamp OEM, lt1298, NE555 Timer, Nand Gate, Frequency to
    voltage
    converter, Interval timer.

    I am feeding the the regulator from a nine volt battery and it
    is producing
    5.2 volts. The I.C is getting warm. It is not heat sinked.
    Is it normal for the I.C to get warm or is it that some thig is
    wrong?

    _______________________________________________________________
    _________
    Get Your Private, Free E-mail from MSN Hotmail at
    http://www.hotmail.com
  • ArchiverArchiver Posts: 46,084
    edited 2000-07-02 08:11
    Also, why don't you see how much current this IC is drawing.... and compare
    it to the IC's specs..



    >From: "A.C.Jacques" <acjacques@i...>
    >Reply-To: basicstamps@egroups.com
    >To: basicstamps@egroups.com
    >Subject: Re: [noparse][[/noparse]basicstamps]lm317 regulator
    >Date: Fri, 30 Jun 2000 16:19:29 -0300
    >
    >Linear regualtors like 78XX and LM317 will dissipate exceding
    >voltage as heat like a simple resistor. It is built-in with temperature
    >protection. Difference from input voltage - output voltage will be
    >transformed in heat.This is not efficient. The 9 volt battery will
    >quickly be empty.
    >Switching regulators (DC-DC converters) are more efficient, but more
    >complicated and expensive.
    >
    >ACJacques
    >
    >
    >fernando hood wrote:
    > >
    > > I am using lm313 to drive the following
    > > BASIC stamp OEM, lt1298, NE555 Timer, Nand Gate, Frequency to voltage
    > > converter, Interval timer.
    > >
    > > I am feeding the the regulator from a nine volt battery and it is
    >producing
    > > 5.2 volts. The I.C is getting warm. It is not heat sinked.
    > > Is it normal for the I.C to get warm or is it that some thig is wrong?
    > >
    > > ________________________________________________________________________
    > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
    >
    >
    >
    >

    ________________________________________________________________________
    Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
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