SU741196A1 - Method of discrete measuring of pulse duration - Google Patents

Description

The proposed method is characterized by the following: An electric signal pulse developed by the device circuit (for example, a flaw detector-thickness gauge), the duration of which is necessary to measure, is fed to the input of the measuring circuit. up to a predetermined level (usually this level is determined by the response threshold of the circuit elements). Then, the number of delayed pulses is recorded, the leading edge of which is within the interval of the measured pulse, the number of fixed pulses is counted, and multiplying it by the delay time, the duration of the measured pulse is obtained.

. FIG. 1 and 2 show variants of the device (block diagram of the proposed method.

The first device for implementing the method, the block diagram of which is shown in FIG. 1, consists of the following nodes and links. Match element 1 used only on one input, connected to trigger 2, the output of which is connected to the first input of match 3, - trigger 4, whose input is connected to the output of match 3, and the output to the first input of the next match 5, trigger 6 Matching elements 7 and trigger 8 are similarly connected. All second inputs of the matching elements are connected together with the input of the matching element 1 and form an input bus. All outputs of the flip-flops 2, .4, 6/8 are connected via elements 9a ... 9g of the release, respectively, to elements 10a ... 10g of the display. All triggers are covered by a general reset circuit.

The device works as follows.

The measured kmpulse enters the Bxorf bus. After a time corresponding to its speed and the speed of the coincidence element 1, trigger 2 is triggered; at its output, a signal arrives through the intersection element 9a, an indication indicator OO. From the output of trigger 2, the signal also arrives at the first input of element 3, since the second input also has a measured pulse signal, then its output is a signal switching trigger 4. The signal from its output also goes to the display element and to the first input of the coincidence element 5, etc. The process continues until the end of the measured pulse duration. The discrete fill signals are the leading edges of the trigger pulses and the coincidence element.

The duration of the measured pulse is defined as the number of triggers triggered, multiplied by the total duration of the leading fronts of the trigger and the coincidence element (the circuit uses the same triggers and the same match elements)

The second device for realization of the claimed method (Fig. 2), which differs from the first one in greater complexity, but also in greater accuracy, consists of the following nodes and connections. Elements 11, 12, 13 delays are connected in series. Logic elements or delay lines can fulfill their role. The first input of the matching element 14 is connected to the output of the dropping element 11. The output of this circuit is connected to the input of the trigger 15, the output of which is connected to the display element 20. The output of the delay element 12 is connected to the first input of the coincidence element 16, its output is connected to the trigger 17, and the output of the latter is connected to the display element 21. Other nodes are similarly combined: delay element 13, coincidence element 18, trigger 19, and display element 22. The second inputs of all matching elements are connected together and connected to the input of delay element 11 (device input). All triggers are covered by a general reset circuit.

The device works as follows.

A measured pulse arrives at the input and begins to pass through a circuit of series-connected elements 11, 12, 13 ..., etc., of the delay. After each element it is delayed in time (relative to the moment of arrival) by the value of T p T – j, where T is the delay time, n is the number of elements passed by the pulse. Signals after each delay element arrive at the first inputs of elements 14, 16, 18, and so on. Coincidence. A measured pulse arrives at their second inputs. The signals from the outputs of the matching elements switch the trigger 15, 17, 19it. d., and the latter include elements 20, 1, 23 of the display. Since the signals at the inputs of the coincidence elements are shifted in time by an amount increasing with an increase in their sequence number, then at the output of the matching element for which the signal at the input is delayed by the duration of the measured pulse, there will be no signal. All subsequent triggers and the display elements connected to them will remain in the initial state. The duration of the measured pulse is defined as the number of triggers triggered, multiplied by the length of the leading edge of the signals at the output of the element

delays. Matching elements can be made on resistors with an appropriate trigger level setting.

Claims (2)

1.Gorn LS and others. Elements of nuclear instrument making schemes, M., Atomizdat, 1970, cl 190-198. 2. Ermolov R. S. Digital frequency. measures. L., Energie 1974, p. 34-40. Fi, and. / 93