Circuit Descriptions, Abbreviation List, and IC Data Sheets
9.
Role of Other Components
•
The capacitors 2U06 and 2U10 are filtering the ripple
current generated by the commutation of power MOS-FET
7U04 (about 700 mA_rms, while the capacitor 2U08 is
filtering the output voltage.
•
Coil 5U02 and capacitor 2U15 prevent that noise
generated by the switching will disturb other circuits
supplied from +11V.
•
Coils 5U05 and 5U06 and capacitors 2U23 and 2U31 are
supplementary filtering of the output voltage for the two
load circuits (PIP and Feature Box).
•
Beads 5U03 and 5U04 damp oscillations during the
switching of the power MOS-FETs.
•
Components 2U01, 2U02, and 6U02 are not present (the
voltage "+3V3-ILINK" is not used).
Service Tips
•
When a power MOS-FET is found defective, replace the
other power MOS-FET, the fuse 1U01, and the diode 6U06
as well.
•
When a driver transistor (7U01, 7U02, 7U08, or 7U09) is
found defective, replace the complementary transistor as
well (
example:
replace also 7U08 if 7U02 is defective).
•
For a normal operation of the converter, it is important to
check the switching frequency, the value of the boost
voltage, and the amplitude of the gate voltage of transistor
7U04 (it should be close to the boost voltage).
9.3.3
Power Balance
The total output power is max. 160 W.
Table 9-1 Total power balance overview
9.3.4
Switch On/Off
The set can be switched "on" or "off" via the ON/OFF knob, or
by (dis)connecting the AC power power cord to the power
socket with the ON/OFF knob "on".
9.3.5
Power States
There are four different power states. Some characteristics of
these are summarized in the "Power states overview" table.
Table 9-2 Power states overview
Events from OFF to SEMI-STANDBY or ON
See also figure "Step wise start-up diagram" in chapter
"Service Modes, Error Codes, and Fault Finding".
1.
The set is in "off" state until the ON/OFF switch is switched
to "on". The standby supply starts, +5V2 becomes present,
the OTC resets, the I/O pins are initialised, and the
watchdog is enabled. The set comes in standby mode. The
sets leaves the stand by mode if:
–
A time extraction must be started (after every start up).
–
The Standby bit is set to "off"; when a user switches on
the set, the standby bit is also set to "off".
2.
To ensure a quick start-up of the set, the hardware start-up
of the set should start within 500 ms after an OTC reset is
received, or within 250 ms after a "leave stand by"
commando is received. The total initialisation should be
finished at least within 1500 ms after the OTC reset.
3.
The STANDBY line is set to "low", the +5V_SW is "on", the
relay closes, and the LCD AUX supply starts up (8V6 is
present).
4.
The rest of the ICs are initialised. The EBILD is initialised
min 400 ms after the standby line is set to "low".
5.
If the standby bit was set, the set goes into semi-standby
until the time extraction is done.
6.
If the standby bit was not set, the LCD is switched "on" via
the EBILD.
Events in SEMI-STANDBY
1.
The set can be in semi-standby during "time extraction",
the semi-standby state is ended when:
–
Time extraction has finished.
–
A user event "On"
–
The set goes into protection.
2.
If the standby bit is not set (after user event), the LCD is
switched "on".
3.
If the standby bit is set, the set goes to standby.
Events from ON to SEMI-STANDBY/STANDBY
1.
The set can be switched to standby:
–
Via the RC.
–
Via a protection.
2.
The running instructions are finished.
3.
The LCD is switched "off"; this is controlled by the EBILD.
First, the +24V power is switched "off", and then the power
supply to the LCD is switched "off".
4.
Sound is muted
5.
Protections are disabled.
6.
The OTC sets the STANDBY line "high", this switches "off"
the main power supply, and only the standby supply
remains working.
7.
The set is in standby.
Voltage
Value
Current
P_max
5V2
5.2 V
0.6 A
3.18 W
8V6
8.6 V
0.5 A
4.3 W
+12V_sound
12.3 V
0.24 A continue, 0.81 A
peak
3 W continue, 10
W peak
-12V_sound
12.3 V
0.24 A continue, 0.81 A
peak
3 W continue, 10
W peak
V_tune
50 V
4 mA
0.1 W
12V
12.3 V
0.9 A
11 W
24V_lamp
24 V
5 A
120 W
Total
160 W peak
Power state
On/Off
switch
Remarks
OUT (AC power cord
disconnected)
X
No power.
OFF
OFF
Only standby supply is working.
OTC not powered.
Main supply not working.
No LED is "on".
STAND BY
ON
Standby supply is working.
Red LED is "on".
SEMI STAND BY
ON
Standby supply is working.
Main supply is working.
LCD and LCD-lamps are not active.
Time extraction.
Red and Green LEDs are "on".
ON
ON
The set is working.
Green LED is "on".
Power state
On/Off
switch
Remarks
FTL13U_AA_AB_312278513481.book Page 142 Thursday, December 30, 2004 1:50 PM