SU1290561A1 - Vertical output stage - Google Patents

Abstract

The invention relates to television and provides enhanced functionality by providing operation in an arbitrary type of sweep. The sawtooth voltage of the frame frequency generated by the sweep signal generator 1 is compared in the comparator 2 with the signal generated by the deflection current sensor 5 and the OS adjustment unit 6. The voltage is high or low from the output of the comparator 2 through the key amplifier 3 is fed to the integrating unit 4. In this unit, the choke 13 and the capacitor 15 together with the inductance of the frame deflecting coil 14 form a low-pass filter. This filter selects in the frame deflection roll 14 the first harmonic of the frame deflection current. The introduction of the OS adjustment block 6 allows the invention to be used in device scanners in displaying information with both raster and non-periodic scanning, since no synchronization of the PWM signal with the horizontal scanning frequency is required. 1 il. a G N: With a

Description

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The invention relates to television technology and can be used in information display devices with raster and non-periodic scanning.

The purpose of the invention is to expand the functionality by providing work with an arbitrary type of sweep.

The drawing shows a structural electrical circuit output frame vertical scan.

The frame output stage comprises a sweep signal generator 1, a comparator 2, a key amplifier 3, an integrating unit 4, a deflection current sensor 5, a feedback control unit 6, and a power source 16. In this case, the key amplifier 3 contains the first 7 and second 8 resistors, the first 9, second 10 and third 11 transistors; The integrating unit 4 comprises a transition capacitor 12, a choke 13, a frame deflecting coil 14 and an integrating capacitor 15.

Output stage frame scan works as follows.

The scan signal generator 1 generates a ramp voltage of the frame frequency, the shape of which corresponds to the required shape of the frame deflection current. The signal from the output of the generator 1 is fed to the Jersey input of the comparator 2, to the second input of which is fed from the deflection current sensor 5, through the feedback control unit 6, a voltage proportional to the deflection current. Depending on the ratio of the voltages at the inputs of the comparator 2, a high or low voltage is generated at the output of the latter, which is fed to the input of the key amplifier 3. After amplification by a pre-output cascade (resistors 7 and 8 and transistor 9) and terminal stage (transistors 10 and 11 rectangular pulses are fed to the input of the integrating unit 4. The capacitor 12 serves to eliminate the constant component of the output signal of the key amplifier 3, and the choke 13 and the capacitor 15 together with the inductance of the vertical deflection cat shki 1 form a lowpass filter, koto

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It is intended to isolate the first harmonics of the current deviation in a frame deflection coil 14.

The frame output sweep stage operates with pulse-width modulation (PWM) in the self-oscillation mode, which is ensured by the appropriate and by selecting the depth and phase shift of the feedback signal fed to the second input of the comparator 2 through the feedback adjustment unit 6, which can be made in the form of an adjustable resistive-capacitive divider. In fact, the frequency of self-oscillations should be 3–4 orders of magnitude higher than the frequency of the frame sweep, which will ensure the effective suppression of the switching frequency in the frame current deviation.

The proposed frame scanning output stage does not require synchronization of the PWM signal with the horizontal scanning frequency and can be used in scanners of information display devices with both raster and non-periodic scanning.

Claims (1)

Invention Formula A frame output stage, containing a sweep signal generator, whose input is a frame sync pulse input, and an output is connected to the first input of a comparator, the output of which is connected to the first input of a key amplifier, the second input of which is connected to the first output of the power source, and the output is through the serially connected an integrating unit and a deflection current sensor are connected to a common bus and to a second power supply terminal that is different. In order to expand the functionality by providing work with an arbitrary type of sweep, a feedback control block is inserted, the input of which is connected to the output of the integrating unit, the first output is connected to the common bus, and the second output is connected to the second: comparator input, and the power source is designed as a constant voltage source, Subscription