- on Audio/Video/Photography
- Published in issue 7/2008 on page 58
Simple Audio Power Meter
This simple circuit indicates the amount of power that goes to a loudspeaker. The dual-colour LED shows green at an applied power level of about 1 watt. At 1.5 watts it glows orange and above 3 watts it is bright red. The circuit is connected in parallel with the loudspeaker connections and is powered from the audio signal. The additional load that this represents is 470 Ohm (R1//R3) will not be a problem for any amplifier.