Main Voltages and Over
Main Voltages and Over
-
-
voltage Protection
voltage Protection
22
When the unit is turned on, the TV_Main_On command (high) of IC1100 biases the transistor Q7212
into operation, causing its collector to go “low”. The low at the collector of Q7212 causes the transistor Q7225 to turn
off. As a result, IC7215 goes into operation to provide the Sound_15V output.
When the Panel_VCC_On command is issued, transistor Q7702 turns on causing Q7701 to turn off.
Consequently, IC7212 turns on and outputs 12V. This voltage enters the A board via the connector AP4/A4. It is also
provided to the LCD panel via the connector AP2/A2, the P board, and the connector P5 (not shown in the diagram).
The over-voltage protection circuitry affiliated with each of the regulators monitors for excessive current
and over-voltage conditions. It is designed to turn off the AC power by disabling the SUB_ON signal needed to turn
on the AC relay.
To Next Page
Loading...
