استخدام الدارات المتكاملة في مراحل التردد المتوسط .. كتاب التلفزيون الملون والعادي

8- 6 The use of integrated circuits in the medium frequency phases:

Integrated circuits are used in monochrome and color television, the circuit and its board are close to transistor circuits, but they do not require transformers or link circuits and matching impedances, and integrated circuits have (12) to 20 connection poles. The integrated circuit may have a mounting base as for the valve - and the IF circuit may include transistors and integrated circuits and is called a (hybrid) circuit. Some integrated circuits may include several phases together and in one cover

​​​​​1 - The medium frequency stage of the image.

2- The middle frequency stage of the sound.

3 - AFT (Automatic Fine Tuning) circuit.

4- Color circuit.

The box chart:

The box diagram, Figure (6) - (23), represents a simplification of the work of an integrated circuit in the intermediate frequency stage IF that can be used in monochrome and color TV - it consists of 20 connecting electrodes similar to the shape - and it contains - the first amplification stage IF image. The automatic gain control line AGC has a phase delay circuit

A delayed AGC circuit means that it does not start until the AGC voltage takes over the constant DC bias voltage. This will be explained in AGC circuits and their operation. It is also noted that this integrated circuit also includes some audio IF circuits and the primary amplifier for the video signal - an AGC amplifier - and a voltage regulator by means of Zener. The work carried out by this circuit is:

1- Enlarge the IF signal of the image.

2 - Linear detection of the image signal.

3- Enlarge the image signal.

4 - Image magnifier detector

5 - Delayed AGC circuit for the RF amplifier in the voter.

6- The output signal of the AFT operation circuit.

7 - Audio IF Carrier Detector.

8 - IF carrier amplifier.

9- A reference zener diode for the voltage regulator