SU868691A1 - Device for automatic selection of time interval - Google Patents

Description

(54) DEVICE FOR AUTOMATIC SHBORL TIME INTERVAL

one

The invention relates to a pulse technique and can be used to automatically select a time interval.

A device for automatically selecting a time interval is known, comprising a driver of reference time intervals, elements AND and. triggers 1.

However, the known device is characterized by insufficient speed.

Closest to the proposed technical entity is a device containing a pulse counter, a decoder, triggers, and elements AND, 2.

The specified device also differs to -K insufficient speed.

The purpose of the invention is to increase speed.

The goal is achieved in that the device for automatic time interval selection, which contains a pulse counter, a decoder, triggers, and AND elements, is inserted into a reference time generator, an OR element, and a two-input AND element whose output is connected

to the input of the pulse counter, the input of the two-input element AND through the OR element is connected to the outputs of the AND elements, the first inputs of which are connected to the outputs of the reference time interval generator and to the inputs of D-flip-flops, the outputs of which are connected to the second inputs of the And elements, the synchronization inputs of the triggers are connected via a decryptor to the outputs of the pulse counter, the input of the zero setting of which is connected to the input of the zero setting of the flip-flops and the generator of the reference time intervals.

15 The drawing shows the functional diagram of the device.

The device for automatic selection of an interval contains the element

20 And 1 connected to the bus 2 input signals and to the element OR 3, the output of the element And 1 is connected to the input of the counter 4 pulses, the outputs of which through the decoder 5 are connected to the synchronization inputs of D-type flip-flops, the inputs D of which are connected to the outputs of the ramp 7 the reference measurement intervals and the first inputs of the elements And 8, and the second inputs of the element And 8 are connected to the outputs of the triggers

6 D-type. In addition, the device contains the input bus 9 and 10.

The device works as follows.

In the initial state, impulses arrive at the device input via bus 2, the frequency of which must be measured, impulses with this tracing period arrive at the bus 10 of the former 7 reference intervals. On bus 9, the state of logical O is set, on all outputs of the imaging unit 7 reference intervals, the element OR 3, the elements AND and the counter 4 - the state O, on the inverse outputs of the trigger 6 - the state 1. Element I 1 is closed by the second input with output element OR 3. At the input of the counter 4 pulses from the input of the device are not received.

When installed on the bus 9 of the state of logical 1, the leading edge of the first pulse starts the shaper of 7 standard measurement intervals.

The beginning of all reference intervals is formed simultaneously, so state 1 is set at all inputs of the OR 3 elements, as a result of which the OR 3 element opens the AND 1 element at the second input, the input signal arrives at the input of the counter 4, and the counter 4 counts them .

Using the decoder 5, the contents of the counter 4 are monitored during the counting process for the contents of the counter to be determined with a certain checksum. If the contents of counter 4 become equal to the control., A pulse signal appears on the output of decoder 5, which, on a leading edge, in accordance with the states of the D inputs, sets the triggers 6 to a certain state.

Setting trigger 6 to state 1 when the contents of counter 4 match the checksum eliminates longer measurement intervals from the formation of a measurement interval in the AND 8 and OR 3 elements. This is achieved by the fact that the output of the trigger 6 is connected to the element And 3 of the next, longer etgshonny interval. As a result,

goat reference interval that corresponds to the maximum filling of counter 4 without overflowing the most significant bit. The information on the selected measurement interval consists in the contacting of triggers 6 after the arrival of a pulse from the output of the decoder 5. The contents of the counter 4 are read out after the formation of the measurement interval at the output of the element OR 3 is completed. After reading the result, bus 9 sets the state O and the circuit is prepared to the next dimension.

Thus, in comparison with the known in the proposed device

5, the frequency measurement time is significantly reduced. And corresponds to almost one frequency measurement interval, whereas in known devices the time intervals are sequentially searched.

Claims (2)

1 .. USSR author's certificate 615607, cl. H 03 K 5/18, 1976. 2. USSR author's certificate 443467, cl. H 03 K 3/64, 1972  (prototype).  v / "V  V "M " J i 1 g t oaS 00 I 00 I I 00 I pg L.