Active Crossover Kit for DIY SpeakerBuilders
Loudspeaker 100 Watt Meter, Exponential Scale
This circuit will light up LED’s to show approximately howmuch wattage is being delivered to your speaker. I have never used it, so I can’tmake any promises about its validity. It was given to my by Dave Quakenbush (dhq@juno.com),in order to post it for a Bass List discussion. It seems R1 and R2 form a voltagedivider. Maybe raise R1 to scale for higher wattages?
The following GIF was kindly provided by Dave Dlugos of the TransmissionLine Speakers page.
D1 – D10 LED’s
R1 18k; this assumes a 8 ohm speaker;try 10k for a 4 ohm speaker (no idea about this advice)
R2 10k
R3 390 ohms, * watt
R4 2.7k
C1 10uF, 35V electrolytic
More info on the LM3915 may be found at National Semiconductor: http://www.national.com/pf/LM/LM3915.html