Of course a series clipper would protect the speaker without shorting the amp. Needs a bit of auxiliary power, and would cause a bit of distortion, but nothing awful for a toy application.
Personally I’d just crank down the LM386’s supply voltage.
Cheers
Phil Hobbs
Sure you can. Wire the AC pins across the speaker and short the DC pins.
Cheers
Phil Hobbs
Of course an "8 ohm" speaker isn't really 8 ohms. Audio is such a mess.
A tiny speaker will have basically no bass efficiency, so a series (highpass) cap might protect it.
Imagine a true frequency-selective wattmeter, or a true-power spectrum analyzer.
John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
Doh. Of course. Thanks! Ed
PTC Resettable Fuses AKA polyswitches. 30mA for 0.25w etc...
The simplest and least obtrusive way to protect the speaker is with a potentiometer (pot) between your computer and the input to the amplifier IN(+), as shown figure 9-1 TI datasheet. Main terminals from computer output to COM and pot tap to 386. The 386 input impedance is 50k-Ohm , so a 5k-Ohm pot would keep things effectively linear.
Something cheap and readily available:
Almost anything will do.
Temporarily replace the speaker with a dummy load of 8 ohms. Then note the pot knob positions for SQRT(Pmax x 8) for your various speaker power ratings (0.1, 0.25, 0.5, and 1 Watt should do ) with your computer output turned all the way up. Mark this with an index, even a piece of paper on the shaft if necessary. The SQRT means that the pot adjusted all the way to the top for full 1W power, and 2/3 of the way to the bottom for 0.1W.
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