SU408229A1 - DIGITAL METER - Google Patents

Description

The invention relates to electrical measuring technology and can be used to create electronic counting meters for the duty cycle of a pulse sequence signal.

Known digital meters containing a forming device, a trigger, a strobe counter, a selector, a clock pulse generator, a block of counting decades, and a trigger pulse generator.

However, the known meters do not provide a measurement of the pulse ratio of the pulse sequence.

The aim of the invention is to measure the duty cycle of a pulse train.

For this, the meter is provided with an additional selector, the inputs of which are connected respectively to the output of the main selector and the shaping device, and the output is connected to the input of the gate counter.

The drawing shows a block diagram of the meter.

The digital meter contains the source of the signal under study 1, connected to the input of the forming device 2, the output of which is connected to the input of the additional selector 3. The output of the additional selector 3 is connected to the input of the strobe decade counter 4, the output of which is connected to the zero input of the trigger 5. The single output of the trigger 5 is connected with the input of the selector 6, the second input of which is connected to the output of the clock pulse 7. The output of the selector 6 is connected to the second input of the additional selector 3 and to the input of the block with even decades 8. The output of the trigger pulse 9 is connected to the unit input of the trigger 5, the output of which is also connected to the inputs of the zero setting of the gate counter 4 and the block of counting decades 8.

The device works as follows.

With the beginning of the measurement, the starting pulse shaper 9 generates a pulse that sets the trigger 5 to a single state, and the block of counting decades 8 and the strobe decade counter 4 to the zero state. The signal from the single output of the trigger 5 is fed to the input of the selector 6, to the second input of which clock pulses with a follow-up period much smaller than the duration of the measured pulses are received from the clock pulse generator 7. The clock pulses, having passed the selector 6, are fed to the block of counting decades 8 and to the input of the additional selector 3. The clock pulses pass the additional selector 3 only when a pulse obtained in the shaping device 2 from the measured pulses is present at its second input.

When overrun gating decade counter 4, having a fixed capacity

p, where n is the number of decades in the counter, the overflow pulse returns the trigger 5 to the zero state, thereby stopping the flow of clock pulses to the block of counting decades 10 and to the gate decade counter 4. During the measurement time, the clock pulses Ki go to the gate decade 4 frequencies, and in the block of counting decades 8 - K2 clock pulses. The durability of the signals Q is determined by the expression

K2

Q

TO,

The counting of pulses by a block of counting decades 8 and a gated decade counter 4 stops at the moment when Ki becomes equal to 10, while Ka is fixed by block of counting decades 8. Since Ki 10, division by Ki is performed by shifting the comma by n bits to the left, and since n is a fixed number embedded in the construction of the device, this shift is also made fixed. So

Thus, in the block of counting decades 8, a number equal to the duty ratio multiplied by 10 will be registered,

Subject invention

Digital meter containing a forming device, serially connected strobe counter and trigger, output

which is connected to one of the selector inputs, to the other input of which the output of the clock generator is connected, while the output of the selector is connected to one of the inputs of the block of counting decades, to the other input of which, as well as to the inputs of the strobe counter and trigger, the output of the trigger pulse generator is connected, characterized in that, in order to measure the pulse ratio of the pulse sequence, it is equipped with an additional selector, the inputs of which are connected respectively to the output of the main selector and the forming device -keeping, and an output connected to an input strobe counter.