TV Receiver Vertical (TVRV)

Substance:

VERTICAL DEFLECTION
VERTICAL GENERATOR
REMP GENERATOR
VERTICAL OUTPUT GENERATOR
VERTICAL FEEDBACK
PUMP UP
DISCRIMINATION
VERTICAL DEFLECTION CIRCUIT
PULSE AMPLIFIER
HORIZONTAL DEFLECTION
HORIZONTAL OSCILLATOR
HORIZONTAL DRIVE
HORIZONTAL OUTPUT
HORIZONTAL AFC (Automatic Frequency Control)
GRAPHIC OF WORKING WAVES IN AFC CIRCUIT

1. Vertical Deflection

This section functions to provide current with a sawtooth signal to the deflection yoke so that the electron beam can scan in the vertical direction of the screen.

2. Vertical Generator

It is a circuit that functions to generate vertical frequency pulses with a frequency of 50Hz for the CC IR system (for the FCC 60 Hz system). Older TV models are sometimes still found using an RC Oscillator circuit that has a "V Hold control adjustment" but currently almost all TVs use a vertical countdown system that does not require any adjustment at all.

3. Remp. Generator

Functions to form sawtooth pulses from Oscillator pulses.

4. Vertical Output Generator

To provide sawtooth current to the deflection yoke coil, a voltage in the form of a "TRADESOID" is required. This is because the vertical coil is not purely inductive but also has receptive properties from the resistance of the coil material itself:

Vertical Output Generator

5. Vertical Feedback

Because there is non-linearity in the parts, oscillator section, remp.regulator or vertical output amp, it causes the resulting sawtooth current to be non-linear, this causes the GB. to become elongated at the top or shortened at the bottom of the screen to eliminate the defect, a negative feedback circuit must be installed from the vertical output amp section to the remp.generator.

Two types of feedback are needed to improve the linearity of the vertical section, namely:

DC feedback, namely DC voltage feedback from the vertical out pin to the remp.generator.
AC feedback, namely pulse feedback from the vertical output after passing through the capacitor couple to the ramp generator.

DC and AC feedback circuit on IC 201

AC/DC Feedback Circuit

6. PUMP UP

It is a circuit that functions for power efficiency, so the vertical out uses 2 types of source voltage, this is still found in TV circuits that still use transistors for the vertical out amp section as follows:

Low voltage is applied during vertical scanning.
High voltage is applied when the vertical pulse retrace

Pump-up functions to produce a high voltage supply from a low voltage supply.

Pump up

7. Discrimination

This is a part that functions to differentiate the vertical frequency of the received video signal and will output an "H" voltage if the vertical frequency = 50 Hz and "L" if the horizontal frequency = 60 Hz.

8. Vertical Deflection Circuit

Vertical Deflection Circuit

The sync signal from the sync separator circuit is integrated by C401 which is connected to pin 35 of IC 601, where the sync.HOR. signal which has a narrow pulse width is discarded.
Oscillation of 50Hz works according to the switching TR. which is in IC601, oscillation will occur along with the charge and discharge on C400 which is connected to pin 34 IC601, the vertical oscillation frequency depends on the charge/discharge time of C400.
A sawtooth pulse can be generated at pin 33 of IC601 which is connected to C420.
The drive pulse for the vertical output comes from pin 31 of IC601, then is fed to pin 4 of IC401 (Vertical output hybrid IC).
The vertical output pulse comes out of pin 2 of IC401 and is fed to the deflection yoke.

Vertical Deflection Circuit Block 2

9. PULSE AMPLIFIER

In the first 1/2 period of the vertical pulse, Q1 is on and Q3 is off, the electric current flows towards the deflection yoke, charging C418. In the next 1/2 period, Q2 is off and Q3 is on, the C418 charge releases its contents which flow towards Q3 then GND via the deflection yoke. At the same time, C412 charges as much as the supply voltage. When the vertical pulse is in the blanking period (retrace), Q5 becomes cut off so that D410 is also off. Therefore, during the blanking period, the voltage at pin 3 of IC401 is 2x 24Volt = 48Volt.

10. HORIZONTAL DEFLECTION

This current functions to provide a sawtooth current, which will later be fed to the deflection coil so that the electron beam on the CRT can scan in the horizontal direction correctly, in addition the Horizontal circuit is also used as a high voltage generator for the CRT anode and to generate several other types of medium and low voltages.

The parts of the Horizontal Deflection circuit include:

11. HORIZONTAL OSCILLATOR

It is a horizontal frequency pulse generator for the CCIR system with a frequency of 15,625 Hz and the FCC system has a frequency of 15,750 Hz.

12. HORIZONTAL DRIVE

This is the part used to amplify the Horizontal frequency of the Oscillator, in order to provide sufficient current to drive TR.HOR.OUT, so that during the "ON" period, TR can fully saturate or truly be "ON".

13. HORIZONTAL OUTPUT

This section functions to provide sawtooth current power for feed to the Horizontal deflection coil of TR.HOT which is then capacitively coupled to the deflection coil.

14. HORIZONTAL AFC (Automatic Frequency Control)

This circuit functions to eliminate interference in the Horizontal section, so the osc.hor is always equipped with an AFC circuit that functions to keep the frequency and phase of the HOR. scanning signal always stable.

The HORIZONTAL range includes:

Horizontal Oscillator, Horizontal Drive and AFC (Automatic Frequency Control) circuit where the AFC circuit will compare the pulse generator (OSC.HOR) with the sync.HOR signal and the difference in the output is in the form of voltage. In the Horizontal driving pulse generator which seems to create a stable sync. by directly measuring the sync pulse. hor. because the frequency of the hor. pulse is very high, the sync. is easily disturbed by noise from outside.

15. WORKING WAVE CHART OF AFC CIRCUIT

Working Wave Chart of AFC Circuit