25
9. TECHNICAL DESCRIPTION
The Peak Detector (explanation about Front L CH)
1) First stage of QG01 <NJM4558DD> (on PG01) functions for comparator.
2) The input signal voltage at JE01 <INPUT Front L> (on PE01) is sent to the 3 pin of QG01 by way of CG01 (on PG01)
and RG01 (on PG01), part of Speaker Output voltage is sent to the 2 pin of QG01 by way of RN55 (on PT01), CG05
(on PG01) and RG06 (on PG01).
3) The 2 pin voltage is same to the 3 pin until about 1.5V input voltage at JE01. Therefor the 1 pin of QG01 output
voltage is 0V.
4) When input voltage at JE01 is more than 1.5V, Speaker Output voltage reaches at clipping level and the 2 pin
voltage is different from the 3 pin.
5) Then some voltage appears at the 1 pin of QG01.
6) Negative voltage is taken out by DG01 (on PG01) and DG02 (on PG01), then QG02 <2SA608SP/ETC> (on PG01)
becomes ON and PEAK LED turns on.
Notice: The PEAK LED turns on little in usual operation, This turns on when input voltage at JE01 becomes 1.5V over
and Speaker Output voltage is more than 36V.
To Next Page
Loading...
