Crt/Yoke Assemblies - JVC 250 Service Manual

5.10 CRT/Yoke Assemblies

CRT/Yoke Assemblies - Main Function
CRTs converts image signal to image light
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Yokes provide horizontal and vertical deflection for CRTs
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Yokes provide x-axis and y-axis convergence correction for CRTs
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CRT/Yoke Assemblies - Inputs
To Yokes
H_RGB_YOKE (pos.) - top of red, green, and blue horizontal yokes.
V_RGB_YOKE (pos.) - top of red, green, and blue vertical yokes.
RGB_LOCK (pos.) - interlock for red, green, and blue yokes (5 V when closed or
15 V when open).
X_RGB_YOKE (pos.) - top of red, green, and blue X-axis Convergence yokes.
Y_RGB_YOKE (pos.) - top of red, green, and blue Y-axis Convergence yokes.
To CRTs
Anode Voltage from High Voltage Power Supply (25 kV).
Focus Voltage from High Voltage Power Supply (7 kV).
RGB G - G grid signal from Video Amplifier PCB.
1 1
RGB G2 - G2 supply voltage from Video Amplifier PCB (about 600-800 V).
RGB_CATHODE - video output signal from the Video Amplifier PCB (about 40
Vpp with a peak voltage of about 70 V).
RGB_HEAT (pos.) - positive side of CRTs heater voltage (about 6.2 V).
CRT/Yoke Assemblies - Output
From Yokes
H_RGB_YOKE (neg.) - bottom of red, green, and blue horizontal yokes.
V_RGB_YOKE (neg.)- bottom of red, green, and blue vertical yokes.
RGB_LOCK (neg.) - interlock for red, green, and blue yokes (5 V when closed or
0 V when open).
X_RGB_YOKE (neg.) - bottom of red, green, and blue X-axis Convergence
yokes.
Y_RGB_YOKE (neg.) - bottom of red, green, and blue Y-axis Convergence
yokes.
From CRTs
RGB_HEAT (neg.) - negative side of CRTs heater voltage (0 V).
ARC_GND - CRTs ground (Anode supply return line).
Model 250 Service Manual
Chapter 5---Electronics
5-51