SU941904A1 - Device for determination of harmonic signal extremum moments - Google Patents

Description

This invention relates to a measurement technique.

A device containing a reversible counter, a generator, a phase detector, a mixer, a digital phase detector, a frequency divider 1 is known.

However, this device has the complexity of construction and gives a low accuracy in determining the moments of the extremum. one

The closest in technical essence is a device in which the duration of the positive half-cycle of the signal under investigation is first recorded in digital form, and then in the next half-period the point in time is recorded when during the counting process the contents of the counter reach a value corresponding to a quarter of the signal period 2.

A disadvantage of the known device is the structural complexity of the circuit, large hardware costs.

The purpose of the invention is to simplify the design.

Claims (1)

The goal is achieved by the device for determining the moments of extremes of the harmonic signal, containing a pulse generator, the first output of which is connected to the counting input of the first counter through the first key, a zero-body whose input is the input of the device, and the output is connected to the control input of the first key, and the second key, the output of which is connected to the counting input of the second counter, contains the OR element and the delay element, while the output of the null organ is connected to the zero counter input of the first counter through the delay element; the rows of which are connected to the information inputs of the second counter, the control input of which is connected to the output of the null organ, the outputs of the discharge of the second counter through the OR element are connected to the control input of the second key, the information input of which is connected to the second output of the pulse generator and the transfer output of the second bit counter is the output of the device. The drawing shows the block diagram of the proposed device. The device contains a zero-body 1 delay element 2, counters 3 and keys 5 and 6, the element OR 7, the generator 8 pulses, input 9, output 10 of the device. The device works as follows. In the initial state, the key 5 is opened by a signal from the output of the null organ 1, the key 6 is closed by a signal from the output of the element OR 7. From the outputs of the generator 8 to the inputs of the keys 5 and 6 are supplied pulse sequences, and to the input of the key 6 are double frequency pulses. At the moments of time when the input signal under study passes from negative values to positive and from positive to negative, i.e. 8 each half cycle nullorgan 1 forms a short voltage pulse. For the duration of the impulse, the key 5 is closed. In addition, the contents of counter 3 are rewritten into counter 4 in an additional code. After the time delay necessary to reliably transfer the contents of counter 3 to counter 4, the pulse resets counter 3 to the zero state. At the moment of termination and pulse, key 5 is opened. Through him, pulse 3 is sent to counter 3. In this way, in code 3, a code is formed that propagates half the period of the signal under study. As soon as the state of the counter becomes different from zero, the element OR 7 is triggered and the key 6 is opened. At counter k, key 6 receives a double-frequency pulse sequence. As soon as the number of pulses arriving at counter k from generator 8 is compared with the code rewritten from counter 3, a high pulse is generated at the output of the high bit of counter 4, the occurrence time of which corresponds to the extreme value of the signal under study. This pulse appears a quarter of a period after the start of counting and, therefore, corresponds to the appearance of the input signal extremum. At the moment of counter zeroing, the element OR 7 closes key 6. Next, the described process repeats and short pulses appear at the output of the device at times corresponding to the smallest and smallest values of the harmonic input signal. The technical and economic effect of using the invention is due to a decrease in hardware costs, an increase in the reliability of operation, as well as an improvement in the dynamic characteristics (the time required for comparing codes is excluded.) Invention The device for determining the moments of extrema of a harmonic signal containing a pulse generator, the first output of which is through the first the key is connected to the counting input of the first counter, the nullorgan, whose input is the input of the device / and the output is connected to the control the first key input, and the second key, the output of which is connected to the counting input of the second counter, characterized in that, for the sake of simplicity, the device contains an OR element and a delay element, while the zero-organ output is connected to the zero counter input through the first counter element The outputs of the bits of which are connected to the information inputs of the second counter, the control input of which is connected to the output of the nullorgan, the outputs of the bits of the second counter through the OR element are connected to the control input of the second key, the information input to torogo connected to the second output of the pulse generator, and the output transfer significant bit of the second counter is the output device. Sources of information taken into account in the examination 1. US patent number, class. I, publish. 1973. 2. Autonomous certificate of the USSR. G 01 R 23 / 16,1978 (prototype). t 1 i /