Changhong Electric PF2939, Руководство по обслуживанию, Страница: 16 / 47

SERVICE MANUAL
14
3) Terminal Function
Table 14
PIN No. NAME FUNCTION
1 Offset canceling filter
DC offset canceling filter for bass boost.
Connect a capacitor (10uF) between this terminal and
GND.
2
3
4
5
φ
4
φ
3
φ
2
φ
1
Terminals for capacitors of the phase shift blocks.
Value of phase shift each block is [deg.]=-2tan-1(2 fCR).
C is capacitance of external capacitor.
R is resistance of internal resister (10k (Typ.)).
Ω
6
8 Lch input
Rch input
Audio input terminals.
7 GND GND terminal.
9 Bias filter
Filter for noise rejection of the bias.
Connect a capacitor (4.7[uF]) between this terminal and
GND.
10
15 Bass LPF (R)
Bass LPF (L)
LPFs for bass control circuits.
Connect capacitors (0.027[uF]) between each terminals
and GND.
11
14 Treble HPF (R)
Treble HPF (L)
HPFs for treble control circuits.
Connect capacitors (8200[pF]) between each terminals
and GND.
12
13
16 Wch output
Rch output
Lch output
Audio output terminal.
17
18
19 Woofer LPF 1
Woofer LPF 2
Woofer LPF 3
LPFs for bass boost circuit.
Connect a capacitor (0.033[
μ
F]) between terminal 17
and GND.
Connect a capacitor (0.047[
μ
F]) between terminal 18
and GND.
Connect a capacitor (0.022[
μ
F]) between terminal 19
and GND.
20 Vcc
Vcc terminal.
Recommended operation voltage is 9[V]+-10[%].
21 Volume filter
Smoothing filter for volume control.
Connect a capacitor (0.01[
μ
F]) between this terminal and
GND.
22 Woofer filter
Smoothing filter for bass boost level control.
Connect a capacitor (3.3[
μ
F]) between this terminal and GND.
This filter is also for ALS circuit.
23 SCL SCL
24 SDA SDA