SU600513A1 - Digital meter of quasiharmonic signal time period - Google Patents

Description

one

The invention relates to the field of measurement technology and can be used to improve the noise immunity of digital period meters and the purity of quasi harmonic signals.

The known period meter signals containing a forming device, a time relay, a series-connected generator of emulsions, a selector and pulse counters, as well as a reset circuit and an AND-I circuit {. However, such a meter has a low noise immunity.

Also known is a digital period meter of egigals containing a shaping device, a control device, a key, an immersion measuring counter, and an imizles generator 2. This device also has low noise immunity, especially with regard to wideband interference.

The aim of the invention is to improve noise immunity. This goal is achieved in that a digital meter containing a pulse shaper, a pulse generator and a serially connected control unit, a key and a pulse counter meter, additionally introduces a matching element and a successively connected trigger, key, imulse counter and code comparison unit, the second inputs of which are connected with the outputs of the measuring pulse counter, and the output with the trigger input. The second trigger input is connected to the pulse driver output, and the output is connected to the first input of the match element. Generator output

the pulses are connected to the second input of the additional key, and the second output of the pulse generator is connected to the second input of the coincidence element, the output of which is connected to the input of the control unit.

FIG. 1 shows a functional diagram of the proposed meter; in fig. 2 - voltage diagrams, measuring the operation of the meter.

The meter contains a pulse former 1, a soviaden element 2, a control unit 3, keys 4 and 5, a pulse generator 6, a measuring pulse counter 7, an emulsion counter 8, a trigger 9 and a comparison unit 10

COD01B.

The input signal to the driver, which forms the output and the short pulses at the moments of transition of the input signal through the zero level from bottom to top and the output b - at the moments of transition from above

way down. The impulses from the output through the element of the soviadena 2 enter the control unit 3, which forms an ir-carbon IMA.

pulse duration is 7; where k is the number of increments of 1 stroke during the measurement; G; - interval

between pulses entering the control unit. If there is no interference, the period of the input signal. In the prototype, for the period T, the input device receives not one, but a few more pulses, due to the level of noise. In this connection, the result measured w may differ from the true several times. To eliminate such errors, a coincidence element 2 is inserted in the meter, which closes for the duration of the "excess pulses." For this, the pulses from the output b of the driver 1, the trigger 9 is transferred to the state opposite to the initial state. Since in the initial state the coincidence element 2 is open and the key 5 is closed, after the arrival of the pulse on the trigger 9, the coincidence element 2 closes and the key 5 opens. The pulses from the generator 6 begin to flow to the counter 8. After the pulses arrive at the input of the counter 8, a pulse arises at the output of the comparison block 10, which returns the trigger 9 to the initial state.

Claims (2)

1. USSR author's certificate No. 327418, cl. G 04F 10/04, 1973. 2. Valitov, R.A., et al., Radio Measurement. M., “Soviet Radio, 1960, p. 421.