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14-4 Vertical Deflection Transistor Barrier Oscillator Circuit:

The schematic diagram (Fig. 4-14) shows the complete vertical deflection stage, containing a transistor barrier oscillator (Q601), driver (602), and vertical output stage (603).

It is noticeable that the barrier oscillator and a generator from the saw are completely similar to the work of the transistor circuit of the transistor barrier oscillator Q601 is the oscillator and the capacitor C604 that gives the sawtooth wave with the parallel resistance R606 in the radiator circuit. The Q601 transistor is of the (NPN) type, so the voltages are polar opposite compared to the diagram in Figure (14-1). It is also noted that the T601 inhibitor oscillator transformer has a third coil, and this coil secures the main connection of the vertical synchronization pulses to the base circuit of the Q601 transistor

Vertical actuator or vertical driver (V-Driver)

The vertical stimulus is the Q602 transistor, which has a common emitter or emitter connection - and we get out of the saw for the stimulus a capacitive connection. As for the vertical output stage 2603, it is inductively connected to the vertical deflection coils, by means of the primary coils of the vertical link transformer T602, and this provides the appropriate impedance for the compatibility between the output transistor and the deflection coils.

Frequency tuning:

The frequency of the vertical oscillator changes by changing the bias value applied through D601 to the base of the vertical oscillator (Q601) There are two controls: the vertical stabilizer R623 and the vertical assist R622 The resistance R622 must be set so that the correct vertical adjustment occurs when R623 is in the middle of it The output circuit of the barrier oscillator is a Q602 vertical trigger amplified sawtooth wave.

Output circuit:

The output of the Q602 is amplified by a vertical output transistor (Q603) and then applied to the vertical deflection coils - the function of the capacitor C611 is to block the DC component of the vertical output signal, and only allow the AC component to be applied to the vertical deviation coils.

Vertical linearity or vertical straightness:

The resistance R625 adjusts the vertical linearity and R605 with C605 form an integrated circuit.

It is used to regulate the sharpness of the sawtooth wave generated by the vertical oscillator barrier, and by changing the value of the resistance R625, the start of the vertical scan (the upper part of the image) can be controlled - and the resistors R612 and R607 and the capacitor C607 provide feedback, which works Correcting the extraneous distortion on the vertical circuit by (Q602 and Q603) - As for the resistance R607 and the capacitor C607, linearity is achieved at the end of the scan
The vertical lower part of the image - and the resistance R624 adjusts the vertical width of the image (height), and this resistance is present in the circuit of the vertical oscillator 2601 - it regulates and adjusts the vertical dimension of the image as well as the linearity of the lower part of the image.

Linear amplifier for output:

The vertical output transistor Q603 should act as a linear amplifier, and the 626 resistor used to adjust the bias works to regulate the linear action of this stage. Failure to adjust properly can make the top or bottom section of the image non-linear.

Q603 Protection:

​​​​​​​The thermistor (TH601) close to the vertical output transistor 2603 is designed to prevent the current passing in the collector circuit of the transistor from being exceeded, which may occur when the ambient temperature rises, and leads to a large current draw in the collector and damages the Q603 transistor. The high temperature of this transistor will lead to a decrease in the value of the resistance of the thermistor, and the incentive to operate Q603 will decrease, and thus the collector current will change. The Q603 transistor is also protected by the circuit consisting of vertical pulse selection diodes 601 -R617- C612 and