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driving 8 ohm, 100 watts speaker — Parallax Forums

driving 8 ohm, 100 watts speaker

ArchiverArchiver Posts: 46,084
edited 2002-06-09 04:39 in General Discussion
Hello, I want to drive an 8 ohm, 100 watt speaker using freqout from the
stamp. Obviously a 386 op amp isn't going to provide enough power. Is
there a super high power version of a 386?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-06-08 21:22
    Dear Raoul:
    Go to www.national.com and check out the LM12C or the LM3886. The LM12C is an
    opamp in a TO-3 package that can deliver 80 watts of sine wave power into a 4
    ohm load. The LM3886 is a class ab amplifier that can deliver 65 watts of audio
    into a 4 ohm load. Both of these IC's are configured like an opamp. They each
    have two inputs an inverting and a noninverting depending on where you apply the
    signal the gain is -RF/RIN or (RF/RIN+1). I can gurantee playing: "Mary had a
    little lamb" with 80 watts RMS is going to be quite loud! ;-)
    -Good Luck!
    -=Randy Knutson



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    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2002-06-09 03:57
    Speakers are very inefficent. I found that an LM380N 2 watt power amp will
    drive my 80W 10 inch speakers OK at fairly loud volume. Remember, the human
    ear is logirythmic (that's why volume control Pots are logirythmic), so in
    order to get twice the power, you would to increase the power 10 tens to a
    20W amplifier, like the LM1875. Both chips are easy to use, however, the
    LM1875 needs + and - 30V rails, whereas the LM380N will work from about 6V
    to 18V single rail. There is also the LM12, 150W Power Op Amp, which I
    briefly played with once...

    Cheers,

    Ben, Wellington, New Zealand.
    --


    > From: raoul vaneigem <raoul@c...>
    > Reply-To: basicstamps@yahoogroups.com
    > Date: Sat, 08 Jun 2002 10:25:39 -0700
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] driving 8 ohm, 100 watts speaker
    >
    > Hello, I want to drive an 8 ohm, 100 watt speaker using freqout from the
    > stamp. Obviously a 386 op amp isn't going to provide enough power. Is
    > there a super high power version of a 386?
    >
    >
    > 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 2002-06-09 04:39
    Opps, typo:

    I meant to say: "...so in order to get twice the volume, you would need to
    increase the power 10 times..."


    > From: Ben Lennard <postmaster@s...>
    > Date: Sun, 09 Jun 2002 14:57:13 +1200
    > To: <basicstamps@yahoogroups.com>
    > Subject: Re: [noparse][[/noparse]basicstamps] driving 8 ohm, 100 watts speaker
    >
    > Speakers are very inefficent. I found that an LM380N 2 watt power amp will
    > drive my 80W 10 inch speakers OK at fairly loud volume. Remember, the human
    > ear is logirythmic (that's why volume control Pots are logirythmic), so in
    > order to get twice the power, you would to increase the power 10 tens to a 20W
    > amplifier, like the LM1875. Both chips are easy to use, however, the LM1875
    > needs + and - 30V rails, whereas the LM380N will work from about 6V to 18V
    > single rail. There is also the LM12, 150W Power Op Amp, which I briefly
    > played with once...
    >
    > Cheers,
    >
    > Ben, Wellington, New Zealand.
    > --
    >
    >
    >> From: raoul vaneigem <raoul@c...>
    >> Reply-To: basicstamps@yahoogroups.com
    >> Date: Sat, 08 Jun 2002 10:25:39 -0700
    >> To: basicstamps@yahoogroups.com
    >> Subject: [noparse][[/noparse]basicstamps] driving 8 ohm, 100 watts speaker
    >>
    >> Hello, I want to drive an 8 ohm, 100 watt speaker using freqout from the
    >> stamp. Obviously a 386 op amp isn't going to provide enough power. Is
    >> there a super high power version of a 386?
    >>
    >>
    >> 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/
    >>
    >>
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