- Published in issue 7/1990 on page 0
Audio power indicator
The LM3915 from National Semicanductor contains virtually everything for making a simple, yet reliable, audio power meter with a bar-type read-out. The circuit has one drawback in that it requires a separate power supply. This is compensated, however, by the fact that it is pretty sensitive (0.2 W min.) arid does not degrade the sound quality in any way, since it does not present an additional load to the amplifier (in centrast, many irrexpensive AF power indicators derive their display current frorn the amplifier).