SU763895A1 - Pulse-frequency subtractor - Google Patents

Description

one

The invention relates to automation and computing, in particular to devices for subtracting non-uniform pulse frequency signals.

Known frequency-pulse subtraction device 1, containing the triggers, the elements AND and OR, the delay element, the driver of the pulses and differentiating nodes.

The drawbacks of the device are the implementation complexity and the limited frequency range of the input signals.

The prototype of the invention is the frequency-pulse subtractive

device G2, containing the first trigger, connected by the first output to the first input of the main element NAND, two elements AND, the first inputs of which are respectively connected to the inputs of the device and the outputs of the elements AND are connected to the outputs of the device. The second inputs of the AND elements are connected to the inputs of the AND-HED element and the outputs of the first and second triggers, respectively. The first input of each trigger is connected with the corresponding input of the device and through the corresponding element is NOT connected to the input of the NAND element connected through the one waiting for the multivibrator with the second inputs of the triggers.

The disadvantage of the prototype is the complexity of the constructive implementation.

The purpose of the invention is to simplify the device | 0 device.

To this end, a pulse-frequency subtraction device containing a trigger connected by a first output to the first input of the main NAND element, and two AND elements,

15 the first inputs of which are respectively connected to the inputs of the device, an additional element IS-NOT is introduced, connected by the first input to the second output of the trigger connected

20 counting inputs with outputs of the NAND elements and the second inputs of the AND elements, and the second inputs of the NAND elements are connected to the corresponding inputs of the device.

25

The drawing shows a block diagram of the device.

Pulse frequency subtractive. the device contains a trigger type UK connected by a counting input

to the outputs of the main and additional elements AND-NOT 2, 3, the first inputs of which are connected to the outputs of the trigger 1. The second inputs of the elements AND-NOT 2,3 respectively connected to the inputs of the device and the first inputs of the elements 4, 5, the second inputs of which are connected to the counting input of the trigger 1, and the outputs are connected to the outputs of the device.

The device works as follows.

Let the pulses of frequency R,, Fg, arriving at the inputs of the device not coincide in time and trigger 1 be in one state.

The first pulse, F, arrives at the input of the element AND-HE 2 and the input of element AND 4. Since the signal from the first output of the trigger 1, which is in the unit state, is present at the other input of the element AND-NOT 2, the signal at the output of the AND- element NOT 2 closes the element AND 4 dl. the passage of the pulse F to the output 6 of the device. The falling edge of the pulse from the output of the element AND-NOT 2 switches the trigger 1 to the zero state, and the output of the element AND-NOT 2 forms a voltage that unlocks the AND 4, 5 elements and permits the passage of subsequent pulses of frequency F through the AND 4 element to the output b device.

When a stream of pulses of frequency F arrives, the device operates in a similar way, but the switching is carried out by elements AND-HE 3 and AND 5.. The first pulse with frequency Frj returns trigger 1 to one, closes element AND-HE 3 and opens element 5. 5. Subsequent impulses frequency fg. arrive through the element And 5 to the output 7 of the device.

If one by one comes

-2

Trigger 1 is switched by each pulse, and the zero potential generated at the output of the corresponding AND-NOT element 2 or 3 closes the passage of pulses of frequency F and F to the outputs of the device.

In the case of coinciding in time pulses from pulses of pulses of frequency F and Fij of equal duration, the device operates as follows.

I When pulses are received, frequency F and F at the inputs of the device, at the entrance of one of the AND-HE elements 2 or 3, which is currently open / a prohibiting pulse is generated. This impulse blocks the passage

and F, j, to the output of pulses of frequency F

devices and alternately switches trigger 1 to various states whereby one of the elements opens and closes another of the elements 4,

Let the pulses of frequency F be ahead of the phase of the pulses of frequency R,: and the trigger 1 is in a single state. In this case, a prohibiting impulse is formed at the output of the NES-2 element, which closes the elements of AND 4 and 5, and the impulse from the stream with the frequency F is in this case forbidden to pass through both the AND-3 element and the output 7 of the device . Upon termination of the pulse from the flow with frequency F, trigger 3 switches to the zero state / IS-NOT 2 blocking element and AND-NO 3 opening element, at the output of which a inhibitory pulse will be generated, but already under the action of a pulse of frequency F,. The impulse from the stream with frequency P < / RTI > trailing edge returns trigger 1 to one state. With the arrival of the next pair of pulses f and P, the process is repeated, at the outputs b and 7 of the device there are no pulses.

If for this mode of operation the trigger 1 at the initial moment of time was in the zero state, then the first pulse from the stream with frequency F will pass to the output 6 of the device, and the first pulse from the stream with frequency F will switch trigger 1 into one state. The operation of the device for the next pair of pulses is similar to that described.

For pulse sequences with a frequency F, lagging in phase, but partially coinciding in time with pulses from a stream with frequency F, the device p. Works in a similar way.

The described device is simpler than the prototype in a constructive implementation that is achieved due to the exclusion from the device of the waiting multivibrator and the second trigger.

Claims (2)

1. Authors certificate of the USSR 452828, cl. G About F 7/385, 1973. 2. USSR author's certificate  572784, class G 06 F 7/385, 1975 (prototype).