Technicolor - Thomson ICC19, Принципы и обслуживание

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POWER SUPPLY INTERLOCKS
Overloads and short circuits are detected by analysing the primary current in
the emitter resistor of TP060 (input at Pin 3 of circuit IP060).
The sensitivity of this stage was increased in Standby Mode to detect errors in
the low-voltage secondaries (RP065, TP027, and RP059). For this reason,
when an incident occurs in Steady State on a secondary other than U SYS, it
is necessary to go to Standby Mode to trigger the interlock.
- An overload or short circuit on voU VERT or +10 V STBY leads to
power supply VCC1 of the regulation and sweep circuit (IV001) disappearing.
- An overload or short circuit on +US causes TP190 and TP170 to conduct.
This forces the breathing interlock input of the regulation and sweep circuit
(IV001) to be triggered by a low level.
- An overload or short circuit on -US causes DP190 and TP170 to conduct,
and triggers the IV001 interlock.
In the event that external speakers with too low an impedance value are
connected (Dolby versions), or when incidents occur on the +5 V, simply shut
off the sweep to remove the overload:
- Excessive current in Resistor RP130 causes TP129 and TP170 to conduct,
and triggers the IV001 interlock (audio mute).
- A short circuit on the +5 V blocks TP175 through the action of DP178, and
causes TP170 to conduct (see sweep interlocks), causing the IV001 interlock
to trigger and the +13 V to disappear.
NOTES :
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