SU1319257A2 - Sawtooth voltage generator - Google Patents

Abstract

The invention relates to a pulse technique and can be used in scanners of transmitting television cameras with high resolution. Introduction of a key 14, a two-level comparator 15, and a peak detector 16 to the generator improves the stability of its operation by increasing the stability of the output pulse when there is interference on the sync bus. 2 Il. “(L SO SO oo 1 NJ fPu8.i

Description

The invention relates to a pulse technique, can be used in scanners of transmitting television cameras with high resolution and is an improvement of the device according to the author. St. No. 783965.

The purpose of the invention is to increase the stability of the device operation by increasing the stability of the output pulse range in the presence of noise along the timing bar.

FIG. 1 shows the structural electrical circuit of the device; in fig. 2 - plots showing his work.

The device contains a parallel-connected discharge switch 1, a source of charge current 2 and a storage capacitor 3, the first connection point of which is connected to a common busbar, and the second to the output busbar 4, connected in series an amplitude comparator 5, an integrator 6 and a compensating current source 7, the output of which is connected to the output 1 line 4, the standby multivibrator 8 and the element 9, the first input of which is connected to the input of the waiting multivibrator 8 and 10 times the synchronizing pulses, the output - to the control input of the dongle 1, and w The input is with the inverse output of the standby multivibrator 8, two analog switches 11 and 12, the control inputs of which are connected to each other and with the direct output of the standby multivibrator 8, and the outputs with the inputs of the amplitude comparator 5, and the signal input of the first analog switch 11 is connected to the output bus 4, and the signal input of the second analog switch 12 is connected to the bus 13 of the reference array, an additional switch 14, a two-level comparator 15, a peak detector 16, whose input is connected to the output bus 4, and the output to the first op A dual input comparator 15, the second reference input of which is connected to PP1NOY 17 of the reference voltage source, the signal input — with an output thickness of 4, and the output — with the control input of an additional switch 14 connected between the forward output of the waiting multivibrator 8 and the control input analog switches 11 and 12.

The sawtooth generator operates as follows.

During the forward stroke of the saw-tooth voltage, the storage capacitor 3 is charged with a direct current of the source 2 of the charging current and a linearly increasing voltage is formed on it 2, its voltage. With the arrival of the synchronizing pulse to the input (10) of the oscillator awhile, the multivibrator 8 is activated and its output impulse leads to switching of the analog switches 11 and 12, resulting in the inputs of the amplitude comparator 5

Two voltages are applied: the reference voltage EO (rail 13) and the voltage pulse from capacitor 3 (from output rail 4). Differential voltage

the output of the amplitude comparator 5 is fed to the input of the integrator 6, the output signal of which controls the value of the current of the source 7 of the compensating current. After the end of the pulse of the waiting multi-vibrator 8, the analog switches 12 and 11 are opened and the synchronizing pulse through the AND 9 element is fed to the input of the bit 1. The discharge key 1 is activated and the discharge of the capacitor 3 starts. After the synchronization pulse ends, the discharge key 1 opens and the formation of the forward stroke of the saw-tooth voltage begins in the device. From period to period, the voltage sweep on the output splint increases and reaches the EO value in 10-20

 periods of the signal (Fig. 2a).

When spurious or missing the necessary clock pulses appear, the operation of the device does not differ from that described above, but the additional key J4 remains open all the time and at the output of the integrator 6 the signal level does not change.

Consider the essence of this process in more detail.

0 Suppose that after establishing the nominal pulse width a false clock signal arrives (Fig. 26). The switches 11 and 12 do not activate, because at the time of this false pulse the voltage swing

5 on the output busbar is less than the output voltage of the peak detector 16 Un-a. The additional switch 14 will remain open, and the charge current of the capacitor 3 from source 2 and 7 does not change.

A similar phenomenon occurs when the clock pulse is passed (Fig. 2c), since in this case the sweep of the saw-tooth voltage exceeds the upper threshold of the comparator 15 (E).

5 Thus, in the proposed device, the required charging current of the storage capacitor is maintained unchanged despite the gaps or premature arrival of synchronizing pulses. Span adjustment

0 a sawtooth signal is automatically performed during periods of normal device operation.

Claims (1)

Invention Formula  Generator sawtooth voltage aut. St. No. 783965, characterized in that, in order to increase work stability by increasing the span stability output pulses in the presence of interference on the synchronization bus, an additional key, a two-level comparator, a peak detector, whose input is connected to the output bus, and an output to the first reference input of the two-level comparator, the second reference input of which are entered into it connected to the onopHOixi lui- source bus, the signal input to the output bus, and the output to the control unit. The second input is an additional key, which is connected between the direct output of the waiting multivibrator and the input of the analog switches. FIG. 2