TX-DS494/HT-R490
GND
3.3k
10k
1SS133
3.3k
0.01 F
GND
0.1 F
35Vp-p
1. Confirmation of speaker relay
Confirm that the speaker relay turns ON approximate 5 seconds after the power switch is turned ON.
Confirm that the speaker relay turns OFF immediately after the power switch is turned OFF.
2. Confirmation of DC detection circuit
1. Press and hold down
CD
button, then press
SPEAKERS A
and
SPEAKERS B
buttons at the same time.
2. Press DVD button, while "
TEST-1_
" on the FLtube is displayed.
During "
TEST-1-00
" on the FL tube is displayed.
3. Press
SPEAKERS A
button button
During "
TEST-1-01
" on the FL tube is displayed.
4. Apply DC 1.5 3V to
MULTI CHANNEL INPUT
terminals with no load.
Confirm that the speaker relay turns OFF.
5. Apply DC -1.5 3V to
MULTI CHANNEL INPUT
terminals with no load.
Confirm that the speaker relay turns OFF.
3. Confirmation of Current detection circuit
1. Press and hold down
CD
button, then press
SPEAKERS A
and
SPEAKERS B
buttons at the same time.
2. Press
DVD
button, while "
TEST-1_
" on the FLtube is displayed.
During "
TEST-1-00
" on the FL tube is displayed.
3. Press
SPEAKERS A
button button
During "
TEST-1-01
" on the FL tube is displayed.
4. Connect Differentiator below and apply the 50Hz square signal to the
MULTI CHANNEL INPUT
terminals.
5. Adjust the attenuator or Volume so that the output level becomes 35V p-p.
6. Confirm that the speaker relay does not turn OFF when a 3.0 ohm load is connected.
7. Confirm that the speaker relay turns OFF when a 1.0 ohm load is connected.
Input
50Hz
Square wave
Output
Unit
Speaker
terminal
Load
Oscillo-
scope
Attenuator
Differentiator
AF Oscillator
CD
Terminal
Differentiator
CONFIRMATION
CONFIRMATION OF PROTECTION CIRCUIT
