SU871095A1 - Servo converter of inter-pulse interval to code - Google Patents

Description

(54) FOLLOWING CONVERTER PERIOD OF FOLLOWING PULSES TO CODE

The invention relates to a pulse and measuring technique and can be used in systems for processing pulse frequency signals. The following transducers of the pulse-to-code period are known, containing a reversible counter, a reference frequency generator, a code-frequency converter and a synchronization unit l. A disadvantage of the known devices is the unevenness of the arrival in time of the pulses of the feedback signal from the code-frequency converter output, which causes oscillation, jitter of the lower bits of the reversible counter, which reduce the accuracy of the device. Closest to the proposed device contains a reversible counter, a reference frequency generator, a synchronization unit connected by an information input to a device input and a synchronous input - to a reference frequency generator, a code frequency converter connected by a control input with a reversible counter, a counting input - to a reference frequency generator and output through the anti-matching circuit - with the first input of the reversible counter, the second input of which is connected to the output of the synchronization unit; the anti-matching circuit with the synchronous input inen with a 2J reference frequency generator. A disadvantage of the known device is low conversion accuracy. The purpose of the invention is to increase the conversion accuracy. This goal is achieved by the fact that the next pulse-period converter is a code containing a series-connected reversible counter and a code-frequency converter, the second input of which is connected to the first output of the reference frequency generator, the second code of the latter is connected to the input of the block

synchronization, entered the trigger and two elements And, the outputs of which are connected to the inputs of the reversible counter. The first input of the trigger is connected to the output of the synchronization unit and to the first input of the first element I, the second input of the trigger is connected to the output of the code-frequency converter and to the first input of the second element I, and the outputs of the trigger are connected to the second inputs of the first and second elements I.

FIG. 1 shows the structural electrical circuit of the proposed device in FIG. 2 - time schedules of the passage of signals.

The converter contains a synchronization unit 1, an alternating pulse elimination unit 2, a reversible counter 3, a code frequency converter 4, a generator 5 of the first frequency. Block 2 contains trigger 6 and elements 7 and 8 I.

The code-to-frequency converter 4 is provided on a controllable frequency divider, which ensures that the pulses in the feedback circuit are uniform in time.

The generator 5 is made with two outputs, the pulse sequences of which are shifted in time by half the period, which allows connecting an anti-coincidence circuit.

FIG. 2 shows timelines for the case of FOC X

2aj 26 — sync pulses, respectively, from outputs 9 and 10 of generator 2c — input pulses of frequency Fj 2g — pulses of frequency Fj at the output of block 1,

2D - frequency pulses FQJ. at the output of the converter 4i

2e, 2g - shaded areas -. Correspond to the state of open elements 8 and 7,

2s, 2s - signals and outputs of elements. 8 and 7,

2k is the value of the Well code at the outputs of counter 3 (the dotted line shows the possible code values in the presence of alternating pulses).

 The operation of the converter is as follows.

In the initial state according to graphs 2e and 2g, the position of the trigger 6 corresponds to the open element 8k. the closed element 7 I. When the first pulse arrives through the channel to the output of the element 7, it does not run. Rear

; by the front, this pulse switches the trigger 6 to a new position, at which element 7 is opened and element 8 is closed. Received via the Ros channel

the impulse (2 d) also does not pass to the output of block 2 (element 8 is closed). With its back front, this impulse tilts trigger 6 to its former position. The second impulse that came through the channel

The FOC passes to the output of block 2 and further to the input of the reversible counter 3. Thus, in the process of operation of block 2, the first two pulse sequences are eliminated, and more than

5 high frequency FQC to the input of the reversible counter 3 passes a differential frequency pulse.

The next pulse on channel F will again be excluded by block 2 (closed

Q element 7). And so, alternating pulses d91 of the next differential frequency pulse shaping will be eliminated. With the arrival of the pulses of the difference frequency to the input of the reversible counter 3, the code at its output is changed in such a way as to reduce the frequency difference u P-Foc R

In the steady-state process, when the frequencies of the pulse sequences FOC and Fx are compared, the formation of differential frequency pulses stops and block 2 continues to operate, interrupting the access of alternating pulses to the inputs of the reversible counter.

Since the frequency converter

/ OCPQ / NT /

where is FO frequency at generator output 5;

N-J. is the output code of the counter 3, then in the steady state N-, Fo TV, i.e. The code at the output of the counter-counter is automatically maintained proportional to the period T of the measured frequency.

Thus, as a result of the exclusion of interleaved pulses by unit 2, the code oscillations at the output of the reversible counter with respect to the steady-state value are stopped, and the accuracy of the converter operation increases.

Claims (2)

The implementation of the generator 5 with two outputs, the pulses of which are shifted in time by half the period, allows for simpler means to ensure the synchronization of the X channels and without the anti-coincidence circuit. The proposed implementation of an exception block — alternating pulses is quite simple and does not require adjustment and selection of parameters. The invention of the Investigation is a pulse period converter to a code containing a series-connected reversible counter and a code-frequency converter, the second input of which is connected to the first output of the frequency reference generator, the second output of the last is connected to the input of the synchronization unit, that, in order to increase the accuracy of the conversion, a trigger and two AND elements are entered into it, the outputs of which are connected to the inputs of the reversible counter, while the first input of the trigger is connected to the output of the syn block and the first input of the first element And, the second input of the trigger is connected to the output of the code-frequency converter and the first input of the second element And, and the outputs of the trigger are connected to the VTO1ShM inputs of the first and second elements I., Sources of information taken into account at 3KcneptH3e 1. Authors certificate of the USSR 417202, cl. H 03 K 13/20, 1974. 2. Authors sbdedelstvo USSR 525033, cl. G 01 R 23/08, 1976 (prototype). fo fe / fx