Table of Contents
Advertisement
I. VIDEO AMP. CIRCUIT
I-1. VIDEO PRE. AMP.
The video pre-amp IC is U301 (KA2143B). The input signal is 0.7Vpp, then pre-amp IC U301 amplify the
video signal to 4~5Vpp. The WHITE BALANCE and CONTRAST shall be adjusted by adjustment the bias
voltage of U301. Fig.4 is the block diagram.
I-2. VIDEO AMPLIFIER
The video amplifier is U303 (LM2439), it amplify video signal to about 40Vpp. Video output signal add to
cathode by AC coupling. The DC bias is controlled by the output pwm of IC U302.
Fig.5 is the block diagram
I-3. BLOCK DIAGRAM
KA2143B
26
Advertisement
Table of Contents
