JVC 340 SC Vertical Deflection Board P/N 102521VDB, Interlocks and Protection, Inputs, Output

Chapter 2—Functional Descriptions

	System Power Supply
Inputs	Description
+48V	Power for horizontal deflection
+15V	Power for the analog section of the HDB
-15V	Power for the analog section of the HDB
+5V	Power for the digital devices on the HDB
GND	Return for HDB

Interlocks and Protection

Input

None

Output

HSENSRED - Used to shut down the CRT beams in the event of horizontal sweep failure.

HSENSGRN - Identical to HSENSERED.

HSENSBLU - Identical to HSENSERED.

Internal

+INLCK

Prevents the horizontal output section from being turned on when 1 or more deflection coils not connected.

-INLCK

!Part of +INLCK circuit.

!Minimum Frequency on Oscillators and PLLs

!Ensures that there will be a sweep in both the horizontal and vertical directions when the sync pulse disappears. This is for protection of the CRT phosphor.

Vertical Deflection Board P/N 102521(VDB)

The Vertical Deflection Board plugs into the electronics card cage and is the second board from the front in the card cage.

The following functions are provided by the VDB:

Drive main vertical deflection coils to provide vertical raster scan for all three (3) CRTs.

Drive all correction coils to provide convergence and geometry correction.

Scan failure detection for all six main deflection circuits.

Vertical size adjustment.

Vertical linearity adjustment.

2-32 Model 330. 340SC, and 370SC Service Manual