Logarithmic Lcd Vu Meter

EE December 1987 LOGARITHMIC LCD VU METER Not so long ago, coloured LED bars were welcomed as the more robust and faster replace- ment for moving coil meters in VU (volume unit) indication units. An additional, important, advantage of the LED VU meter was that it enabled realizing the peak hold function, which is useful, if not indispensable, for determining the recording level on tapes. The major drawback of the LED based VU meter is its relatively high cur- rent consumption, which poses considerable problems in port- able equipment. The VU meter described here is based on a liquid crystal display (LCD) with modest power requirements. The read-out is logarithmic with a scale of 60 dB, which is ad- equate for the dynamic range of, for instance, a CD player. The built-in peak hold function has an option for automatic reset after approximately 2 seconds. Wire links or jumpers make it possible to select dot or bar indication, but it should be noted that the peak hold func- tion opera...