AF power indicator

The indicator is intended primarily heavy-duty PA (Public Address) for loudspeakers. Connected simply to the loudspeaker input terminals. it displays the power applied to the speaker by a row of five LEDs: the larger the power. the more diodes will light. Since the power provided by the output amplifier also influences the total current through the diode array. the brightness with which the LEDs light also increases with increasing power. In this way, only five LEDS give a fairly good indication of the applied power.