audio power meter

audio power meter elektor february 1981 - 2-03 Although this power meter was initially designed as an accessory for the 200 W power amplifier described in the January 1981 edition of Elektor, it can also be used with virtually any other amplifier with one proviso ... as the specification of the above amplifier is 200 W into 4 SZ, this power meter has been designed to be compatible with 4 Sr2 loudspeakers. In addition, the unit has two ranges: 0 ... 50 W and 0 ... 200 W. The easiest way to under- stand how the power meter works is to examine the circuit diagram. ing coil meter, a good quality power meter with a linear scale can be realised. As mentioned previously, the power meter has been equipped with two ranges: one for high power - 200 W, and one for low(er) power - 50 W. This is taken care of by the two potential divider networks, R1/R2/R4 and R3/P1/R4, and the range switch S1. Neither network has to be a precision type as the circuit is calibrated by means of the two pr...