SU856024A1 - Device for detecting and converting video signals - Google Patents

Description

one

The invention relates to radio engineering and measurement techniques and can be used in devices for matching the receiving path with the analyzing equipment in terms of detecting and isolating video signals against the background of interference in various radio electronic systems.

A device for detecting and converting video signals is known, comprising a series-connected matching unit, a key, an integrator, a DC amplifier and a limiter, another input of which is connected to the output of the matching unit, as well as the first delay element and a peak detector whose output is connected through the driver of the reference signal to the first input of the comparison unit, the second input of which is connected to the output of the second delay element 1.

However, this device has a low detection accuracy.

The chain of invention is to increase credibility.

The goal is achieved by introducing two adders and a potentiometric sensor into the device for detecting and converting video signals.

the output of which is connected to the primary input of the first adder, the second input of which is connected to the first input of the second adder and the input of the DC amplifier, while the output of the limiter is connected to the first input of the peak detector, the input of the second delay element, the second input of the key and the second input of the second

10 of the adder, and the output of the comparison unit is connected to the second input of the peak detector through the first transponder element, the output of the first adder being connected to another input of the form of the reference signal body.

The drawing shows a structural electrical circuit of the proposed device.

20

The device contains a matching unit 1, a key 2, an integrator 3, a DC amplifier 4, a limiter 5, a first delay element b, a peak detector 7, a driver 8

25 reference signal, comparison unit 9, second delay element 10, first and second adders 11 and 12, potentiometric sensor 13.

The device works by tracking around 30 times.

The signal from the output of the limiter 5 is fed to the signal input of the peak detector 7, to the input of the key 2, to the input of the second delay element 10, to the input of the second adder 12. The signal delayed by the transition time in the peak detector 7, from the output of the second element 10 goes to the first input of block 9. The reference signal formed with the peak detector 7 and shaper 8 is fed to the second input of block 9. However, in the latter case, the first adder 11 takes part in generating the reference signal. Since the first input of the 9-signal block L output: 5 limiter comes to the amplitude and. gi -tl {4) Orpi l -P | where TJ is the detection threshold;

and - the amplitude of the given pulse signal, then for the comparison of the level from the top of the pulse it is necessary for the shaper 8 to form the reference signal according to the condition

.h CUorpi- Un)) i - U Un Un-U U -Uq i (g)

q 6bixa -C (Ui-Un), (b)

where Urtj is the proportionality coefficient (relative to the level), i.e. the subtraction function in the first case (2) and addition in the second (3) can actually implement a similar-adder, for example, based on an operational amplifier. Therefore, the second inputs of the first and second adders 11 and 12 are supplied with the voltage Up of the detection threshold from the output of the DC amplifier 4, and to the subtracting voltage of Of from the potentiometric sensor 13. The output voltage of the first adder 11 is fed to the second input of the rammer 8, which implements an operation to divide or multiply according to the nature of the coefficient K.

For the subsequent amplitude measurements, using the second adder 12, the amplitude of the i-th pulse is restored as

iiogr1-un - Ci-ip) (4)

Since the time constant of integrator 3 is much longer than the duration of the 1st signal, then the change in Uj during the conversion time can be neglected. In addition, the reduction in the delay of the second element 10 is also positive in this solution, since only the transient process in the peak detector 7 is taken into account, and there is no need to take into account the existence of a signal below the threshold U-.

The proposed device reduces the distortion of the shape and amplitude of the pulses during the conversion process and increases the reliability of the selection of signals.

Claims (1)

1. The patent of Germany 1291791, cl. 21 a 36/15, 1970 (prototype). entrance