دارة AFC الأفقية بالعناصر الصلبة (Solid-Dtate) ٢_a ..

By the transistor (T562) - The connection between the drive stage and the output stage is carried out by the transformer T561. It is an inductive link. The transistor (T563) amplifies the horizontal output, by amplifying the deflection pulses, and gives it to the horizontal output transformer (T562) of port number (2), and from there to the file (L563) that feeds the horizontal deflection coils to move the scanning beam horizontally.

The output is regulated by two transistors MJE344K MT420 and a transistor T421 (SPSS491) - the first changes its resistance between its collector and emitter according to its base voltage connected to the collector of the second transistor (SPS). This voltage, in turn, varies according to the difference between the mains supply voltage (70) and the horizontal output amplifier emitter voltage (73). The Zener diode (D422) between the two transistor radiators regulates a constant voltage difference, and any increase in the horizontal output amplitude leads to an increase in the internal resistance of the transistor (T420), which reduces the horizontal output feeding voltage. It is equal to the difference between the two voltages V - (5) and decreasing the horizontal output feed prevents an increase in the amplitude of the horizontal output pulses - and decreasing the amplitude of these pulses leads to a decrease in the internal resistance of the transistor (T420), which is followed by an increase in the horizontal output feed voltage, and thus the pulses remain with an almost constant amplitude. And he performs

We find that if the general supply is (220) (alternating volts AC, then the voltage Vs is equal to (235) volts), and the horizontal output transistor emitter voltage (BU204) is equal to (95) volts, and the horizontal output feeding voltage is (235) - 95 = 140 volts, which is = (3 - ).

16-4 Sinusoidal oscillators with impedance control:

With us, the AFC circuit voltage corrects the frequency and page of the horizontal oscillator directly, and there is another way to regulate the work of the oscillator by inserting a transistor (impedance) between the AFC circuit and the oscillator, as in Figure (8-16), which shows the simplified box diagram of the circuit, where it feeds the correction voltage ( Arising from the AFC circuit - impedance transistor circuit This transistor in turn rectifies

Synthesis that regulates and adjusts the sinusoidal oscillator. Changing the base bias impedance of the transistor (and the collector current) can increase or decrease the amount of circuit impedance, which in turn enables it to effectively adjust the frequency of the oscillator. The change of the base bias impedance of the transistor is provided by the AFC circuit to regulate the Hartley oscillator. It is of the Hartley type with a very accurate radiating conduction, and due to its very excellent frequency stability and discipline, the user of the device does not need the key to adjust and install the horizontal deviation.

There are two types of impedance transistors used:

1- With induction resistance

2- With a variable resistance connected in series with both types working with DC control voltage originating in the AFC circuit - and adjusting the tuning of the horizontal oscillator.


Variable Resistance Transistor Circuit Diagram:

​​​​​​The diagram of a complete circuit shows the waveforms. Figure (9-16). The capacitor C10 is connected from the collector Q to the base of the tuning oscillator circuit C13 - (L). The wave of form (3) and the output of the stimulus increases to (20) volts from peak to peak. It has a square wave of the shape (4), and the output of the stimulus is connected by means of a transformer to the horizontal output stage.

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