SU949532A1 - Digital meter of relative square pulse duration - Google Patents

Description

A digital meter for the duty cycle of rectangular pulses relates to electrical measuring equipment and can be used in control and automatic control systems.

A device for measuring the duty cycle of rectangular pulses is known, comprising a generator of reference pulses, three keys, a pulse frequency divider, three triggers, a frequency divider by two, an AND gate, a logical HE element, and a pulse counter 1.

A disadvantage of this device is its low speed.

The closest in technical essence is a meter comprising a pulse generator of a reference frequency, first and second keys, a pulse frequency divider, a trigger, and a pulse counter C21.

However, such a meter-has a low-speed, as. the measurement time is determined by the time during which the key is open or the time during which N pulses of the reference frequency (where N is the division ratio) are input to the divider. Thus, the number of periods of the measured signal

n needed to get the result should be significantly greater than one, i.e.

5p 1.

The purpose of the invention is to increase speed.

To achieve this goal in a device containing a generator

10 pulses of the reference frequency, the first Si is the second key, a controlled pulse frequency divider and a pulse counter, the input bus is connected to the first input of the first 15 key, and the output of the reference frequency pulse generator is connected to the first input of the second key, additional keys are entered, pulse counter , as well as two pulse drivers,

20 delay lines and a logical element NOT, and the output of the pulse generator of the reference frequency is connected to the second input of the first key, the output of which is through an additional counter of 25 pulses and an additional key. connected to the control input of the pulse frequency divider, and the output of the second key is connected via a pulse frequency divider,

30 owls to the counting input of the main pulse counter, while the input bus is connected to the input of the logical element NOT whose output is connected to the second input of the second key, to the input of the delay line and to the input of the first pulse shaper, the output of which is connected to the second input additional key and to the installation input of the main pulse counter, and the output of the delay line through the second pulse shaper is connected to the installation input of the additional counter. The drawing shows the functional scheme of the device. Digital porosity meter contains the first key 1, the second key; 2, the generator 3 pulses of the reference frequency, the additional counter 4, the additional key 5, the control divider frequency b, the logical element HE 7, the counter 8, the delay line 9, drivers 10 and 11 impulse sov. The digital meter works as follows. At the initial time, the additional counter 4 pulses is in the zero position. When the first pulse, the duration G, of the measured sequence arrives at the input, the first key 1 opens on its leading edge and the pulses of frequency f from the generator 3 pulses of the reference frequency arrive at for the time T. counting input additional counter 4 pulses. As a result, the N code was fixed in an additional counter of 4 pulses. On the falling edge of the first pulse, the logical element NOT 7 starts the pulse former 11, which opens the key 5 with its impulse, and in the controlled divider 6 of the pulse frequency code N, a factor 1 K is set. The time 1,000 is recorded in the pulse counter 8 pulses ... O, where the number of characters after the comma is equal to / i 1,2. which is equivalent to the arrival of pulses at the input of the counter 8 pulses of 10 pulses. At the same time the logical element NOT 7 opens the second key 2 and the pulses of frequency fp through a controlled divider b of the pulse frequency with a coefficient K are fed to the counting input of the counter 8 pulses during T - t what the code is written in the counter)% ....,: a, Taking into account the position of the comma, we get the value of the pulse duty cycle; a (i ... On the falling edge of the pulse, the logical element NOT 7 triggers the pulse generator 10 pulses through the delay line 9, the output pulse of which turns the additional pulse counter 4 on. The leading edge of the second pulse opens the first key 1 and the measurement cycle repeats. Thus The proposed device makes it possible to significantly shorten the time to measure the duty cycle of rectangular pulses as compared to the known. Formula of the invention A digital meter for the duty cycle of rectangular pulses containing a generator the first and second keys, a controlled pulse frequency divider and a pulse counter, the input bus is connected to the first input of the first key, and the output of the reference frequency pulse generator is connected to the first input of the second key, which, in order to improve speed, it has additional keys and, a pulse counter, as well as two pulse drivers, a delay line and a logical element NOT, the output of the reference frequency generator is connected to the second input of the first key, output which through an additional pulse counter and additional key is connected to the control input of the pulse frequency divider, and the output of the second key is connected to the counting input of the main pulse counter via the pulse frequency divider, the input bus is connected to the input of the logical element NOT, the output of which is connected to the second input of the second key, to the input of the delay line and to the input of the first pulse shaper, the output of which is connected to the second input of the additional key and to the installation move the main pulse counter, and the output of the delay line through a second pulse shaper is connected to the mounting additional entry counter. . Sources of information taken into account during the examination 1. USSR author's certificate No. 550589, class C. 01 R 23/02, 1977. 2. Author's certificate USSR W 376728, class C. 01 R 23/02, 1973.

entrance

Claims (1)

Formula of the invention A digital pulse duty cycle meter comprising a pulse generator of a reference frequency, first and second keys, a controlled pulse frequency divider and a pulse counter, an input bus connected to the first input of the first key, and the output of the pulse generator of the reference frequency connected to the first input of the second key , characterized in that, in order to improve performance, additional keys and a pulse counter are introduced into it, as well as two pulse shapers, a delay line and a logical th element is NOT, and the output of the pulse generator of the reference frequency is connected to the second input of the first key, the output of which through the additional pulse counter and the additional key is connected to the control input of the pulse frequency divider, and the output of the second key through the pulse divider 'pulse repetition is connected to the counting input of the main a pulse counter, while the input bus is connected to the input of the logic element NOT, the output of which is connected to the second input of the second key, to the input of the delay line and to the input of the first a pulse shaper whose output is connected to the second input of the additional key and to the installation input of the main pulse counter, and the output of the delay line through the second pulse shaper is connected to the installation input of the additional counter. ''