SU883854A2 - Device for clamping pulse temporary position - Google Patents

Description

one

The invention relates to a pulse technique and can be used to measure the time intervals between pulses having a different front slope and a large dynamic range in amplitude.

According to the main author. St. No. 553587, there is known a device for fixing the temporal position of pulses, containing lower and upper level discriminators, the inputs of which are combined and are the device input, the output of the lower level discriminator is connected to the first input of the sawtooth generator with an adjustable slew rate, the output of which is connected in series with the output discriminator and standard pulse shaper, the output of which is the output of the device, and the output of the upper-level discriminator is connected to the second input of the sawtooth generator with an adjustable slew rate 11.

The disadvantage of this device is the low noise immunity of the device when it operates in a wide dynamic range of amplitudes of the input pulses, as in the case when the level of interference is high, the low threshold of the low level discriminator must be set, which necessitates an increase in the high level of the discriminator of the upper level. In this case, it is possible that the input pulse does not reach the threshold of the upper discriminator, which leads to incorrect fixation of the time position of the pulse.

To eliminate the phenomenon of incorrect fixation of the temporal position of pulses having a large dynamic range in amplitude, it is necessary to lower the threshold of the low level discriminator,

20 which reduces the immunity of the device and leads to the fixation of false impulses.

The purpose of the invention is to improve the noise immunity of the device when

25 providing a wide dynamic range of input pulses.

The goal is achieved by the fact that a device for fixing the temporal position of the pulses, containing the discriminators of the lower and

the upper level, the inputs of which are combined and are the input of the device, the output of the discriminator of the lower level is connected to the first input of the sawtooth generator with an adjustable slew rate, the output of which is connected in series with the output discriminator and the standard pulse former whose output is the output of the device A trigger has been entered, the information input of which is connected to the output of the upper-level discriminator, the setup input is connected to the output of the device, first and second outputs of the flip-flop are respectively connected to the second input of the sawtooth generator and the control input of the discriminator.

Figure 1 shows the device; figure 2 - timing diagrams illustrating the operation of the device.

The device contains a discriminator

1 lower level, generator 2 saw-tooth voltage with adjustable slew rate, discriminator 3 upper level, output discriminator 4, shaper 5 standard pulse, trigger 6, device input 7, outputs 8 and 9 of discriminator 1 and 3, outputs 10 and 11 of trigger b, output 12 devices.

The device works as follows.

Pulses are received at the device input 7. (Figure 2c (). The threshold level of the discriminator 1 can be set below the noise level. The threshold level of the discriminator 3 is set above the noise level and above the threshold level of the discriminator 1, for example,

2 times. At the time points when the useful impulse or interference signal reaches the threshold level of the discriminator 1, a signal appears at the output 8 of the latter (Fig. 25, the front of which determines the beginning of the formation of the sawtooth voltage by generator 2 at speed V, (Fig. 2a). At that, the duration of the formed sawtooth pulse is determined by the duration of the input pulse according to the level of the discriminator trigger threshold.

1. The amplitude of the sawtooth pulse may be sufficient to trigger the output discriminator 4, but this does not occur, since the latter is blocked by the output from 11 of the trigger 6.

When the input pulse reaches the actuation level of the discriminator 3, the latter triggers (Fig. 2b; and causes switching of the trigger 6 (Fig. 2d). From the output 10 of the trigger b, the differential voltage goes to the generator 2 of the sawtooth, while the speed of the sawtooth changes to V / 2 (Fig. 2c; and from output 11, trigger b - to output discriminator 4, allowing it to be triggered. When the impulse is reached, a sawtooth voltage with speed

V

2 discriminator thresholds

4 it works. From the output of the discriminator 4, the pulse arrives at the shaper 5 of the standard pulse normalized in duration and arrives at the output 12 of the device {Fig.2 The pulse from the output of the shaper 5 sets the trigger b to its initial state, which turns off the generator 2 sawtooth.

 The time interval between the pulses of the imaging unit 5 is equal to the time interval between the beginning of the edges of the input useful signals. Thus, the introduction of the trigger b blocks the output discriminator 3 until the input pulse reaches the trigger threshold of the discriminator 3, which eliminates the appearance of a pulse at the output of the imaging unit 5 when the device has input amplitudes and pulses in the interval

  ReR.

those. in the proposed device, the amplitude of the interference signal may approach the value 2UnoR, (B known - to the value Upop) | 4To means an increase in the noise immunity of the device 2 times.

The relative increase in noise immunity can be any and is determined by the ratio of the levels of sometimes discrimination.

Thus, the proposed device in comparison with the known has a high noise immunity.

Claims (1)

1. USSR author's certificate 553587, cl. G OL F IO / 0O, 1977. Exit about