Amplifier output power-LA 4508

Discussion in 'General Electronics Chat' started by MIRINGU, Nov 8, 2009.

  1. MIRINGU

    Thread Starter Active Member

    Mar 18, 2007
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    0
    Hi, i've these parameters when i used my multimeter to take the readings of an amplifier using IC 4508 . I, had done all the connections ie from radio input to output speaker when taking data.
    Input voltage-12v,500mA. Speaker Output terminal-
    R 2.3 ohms,V 0.04 V.
    Help me get the total output POWER of the amp.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Gee, only about 17.4mA output current through a 2.3 Ohm resistor?
    That's about 695 microwatts.

    Either you're not making the measurements correctly, the IC is bad, or you have something connected up incorrectly. That IC should be able to output up to 2.5A on one channel - with a proper heat sink, of course.
     
  3. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    With a 12V supply its max linear output swing is only 4V peak which is a current of 1.25A into a 3.2 ohm impedance speaker. Its power is 2.5W at clipping into a 3.2 ohm impedance speaker.

    You could bridge its two outputs to drive 5W at clipping into a 6.4 ohm speaker.
     
  4. MIRINGU

    Thread Starter Active Member

    Mar 18, 2007
    75
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    I was using a 3W,4¤ Speaker.
    Audioguru, what does bridging the outputs mean?
     
  5. Audioguru

    New Member

    Dec 20, 2007
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    Bridging the outputs of power amplifiers is when one amplifier drives one wire of a speaker and a second amplifier connected with reverse phase drives the other wire of the speaker. The speaker has each wire driven push-pull. Then an output coupling capacitor is not needed and the voltage swing to the speaker is doubled which results in much more power.

    Car radio amplifiers are usually bridged.
     
  6. MIRINGU

    Thread Starter Active Member

    Mar 18, 2007
    75
    0
    Thanks 4 you replies
     
  7. mbui dennis

    New Member

    Oct 31, 2013
    3
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    Kiambu,si unisaidie na circuit schematics pliz,nko components za (la4508)amplifier lakini nmehata.
     
  8. mbui dennis

    New Member

    Oct 31, 2013
    3
    0
    Anyone with LA4508amplifier pcb wiring.pliz,Nairobi.
     
  9. mbui dennis

    New Member

    Oct 31, 2013
    3
    0
    Anyone with LA4508amplifier pcb wiring.pliz,Nairobi.
     
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