Measuring wattage of LM380N amp.

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  • JonathanAnon
    Badcaps Veteran
    • Jul 2012
    • 457
    • Ireland
    #1

    Measuring wattage of LM380N amp.

    Hi guys,

    I'm building a few small amplifiers with the LM380N 14 pin IC... These are rated for 2.5W, but I'm trying to work out what is the best way to make sure that I dont overdrive them...

    I've seen a few guys on youtube that measure the output wattage by measuring the AC signal across the speaker, squaring it and then dividing by the impedance of the speaker... i.e. power = voltage squared divided by resistance... Is this sufficient to give me a rough idea of what wattage the chip is outputting?

    What's the best way of limiting the chip so that it doesnt output over a certain voltage.. Do I limit the inputs with fixed resistors?
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