Elektornado (NF-Endstufe mit LM391, 2N3055, 2x50W)

Various meters based on the Siemens UAA 170 LED voltmeter IC have previously been featured in Elektor (issue 12, April 1976 and issue 17, September 1976). This article describes a voltmeter circuit using a companion IC - the UAA 180. The voltmeter can be combined with the PPM drive circuit described elsewhere in this issue (`peakmeter`) to make a compact audio level meter, and a novel board layout allows extension of the meter to any required number of LEDs.