Technicolor - Thomson ICC19, Принципы и обслуживание

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GENERATION OF INTERNAL REFERENCES AND POWER SUPPLIES
The power supply at Pin 16 comes from:
On start-up, half-wave rectification of the mains by the mesh RP025, CP054,
and a diode of the bridge rectifier.
In Standby Mode, winding 9, 8 of LP020 (fly-back mode). 12 V obtained by
rectification (DP050, CP054) is applied to regulator IP050 (7809 applied to
Diode DP051), which supplies 9 V via DP052.
In Steady-State, winding 9, 10 of LP020 (fly-back mode). Rectification by
DP053 supplies a voltage of about 11 V.
Note that in this case Diode DP052 is blocked, and disconnects circuit IP02.
Resistor RP054 delivers the power supply to the final stage (Pin 15), and sets
its maximum current.
The circuit supplies several voltages and service signals according to
changes in the direct current voltage at Pin 16.
As soon as +Vdc reaches approximately 4V5, an internal reference of +2V5
is generated.
For +Vdc £ 5V5, a RESET pulse is produced.
When +Vdc reaches 10V3 (Vdc start), enabling of an internal power supply
Vdc int = 5 V. This stabilised voltage allows the circuit to perform well in a
wide voltage range on Pin 16.
This threshold also triggers the passage to high state of Vdc off, thus
enabling the interlock and limit management logic, and authorising pulse
output from Pin 14 (as long as +Vdc remains higher than +Vdc stop, i.e. 7V4
typ.).
For Vdc of 15V7 typ., passage to high state of Vdc max, and interlocking of
the circuit by the interlock and limit management logic.
NOTES :
CENTRE DE
FORMATION TECHNIQUE
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