SU391482A1 - DEVICE FOR MEASUREMENT - Google Patents

Description

The invention relates to instrumentation engineering and can be used to measure the motion parameters of a magnetic carrier in magnetic recording devices.

Devices for measuring fluctuations in the speed of movement of a carrier carrier are known, based on the principle of measuring the frequency deviation of a playback signal on a test instrument of a measurement signal with a stable frequency signal, containing an input signal generator, a frequency modulated signal demodulator, frequency selectors, and a display circuit. However, in known devices, the influence of reproducible signals on the measurement results is not excluded.

The aim of the invention is to increase the measurement accuracy.

For this, the device is equipped with a fault indication circuit consisting of a series-connected pulse generator, a pulse counter, a waiting multivibrator and a loss indicator, and an adder connected by two inputs, respectively, to the outputs of the imaging unit and the waiting multivibrator, and the output to the demodulator input, with This second input of the pulse counter is connected to the input of the summator, and the third input of the counter, through an additional

differentiating circuit - with the output of the adder.

The drawing shows a block diagram of the proposed device.

The device contains a driver /, the output of which is connected to the input of the counter 2 pulses and the adder 3, to the other input of the counter 2 is connected the output of the generator 4 pulses. The output of counter 2 is connected to

the input of the standby multivibrator 5, and its output - with the input of the indicator 6 of interruptions and with another input of the adder 5. The output of the adder 3 through the differentiating circuit 7 is connected to the input of the counter 2 and directly to the input of the demodulator 8, the output of which is connected through frequency selectors 9 to display circuit 10.

The device works as follows. The input signal is fed to the input of imager 1, which generates non-rectangular pulses with a constant amplitude and a variable (due to speed fluctuations) tracking frequency. Shaper 1 output pulses disable pulse counting

generator 4 by the counter 2, in the intervals between the pulses of the shaper 1, the counter 2 produces the counting of the generator pulses. The pulse repetition frequency of the generator 4 b the capacity of the counter 2 is selected in such a way

that in the absence of interruptions in the input signals and maximum changes in the intervals between them, the counter does not overflow.

The output pulses of the driver 1 are also fed to the input of the adder tS and from its output, through the differentiating circuit 7, to the reset of the counter 2. There are no signals at the output of the counter 2. The driver / signal is fed through the adder 3, the demodulator 8 and the frequency selectors 9, which provide the transmission of a signal proportional to the fluctuations of speed, to the display circuit 10, which measures the received signal.

In the case of input signal loss, the absence of a counter-inhibiting pulse of the driver / results: counter 2 overflows, the output pulse of counter 2 is triggered by the waiting multivibrator 5, from the output of which the emulsions go to the 6 loss indicator.

At the same time, the pulses of the standby multivibrator 5 are fed through an adder 3 n differentiating circuit 7 to the reset of counter 2, and the device is brought to its initial state. From the output of the adder, 3 pulses are fed to the input of the demodulator 8. In case of the next pulse disappearing, the operation cycle is repeated. Thus, in the presence of failures, a continuous sequence of pulses arrives at the input of the demodulator.

Indicator 6 loss provides the possibility of accounting for inaccurate statements.

Subject invention

An apparatus for measuring fluctuations in the speed of movement of a magnetic carrier, comprising an input signal shaping device and a serially connected demodulator, frequency selectors and a measurement result indication circuit, characterized in that

increase the accuracy of measurements, it is equipped with a discontinuity indica- tion circuit consisting of a series-connected pulse generator, counter and pulses, a waiting multivibrator and a loss indicator, and an adder connected to two inputs, respectively, to the outputs of the driver and the waiting multivibrator, and the output to the input of the demodule the second input of the pulse counter is connected to the input of the adder, and the third input of the counter, via an additional differentiating circuit, to the output of the adder.