SU362466A1 - AGREEMENT DEVICE OF THE TYPE OF FREQUENCY-CODc5; ... L-.uu. * Uc-fiAH I - Google Patents

Description

The device relates to the field of measurement technology and can be used to measure the frequency of electric signals. A device comprising a prohibition circuit 5, a reference frequency generator connected to a binary multiplier including a result counter connected through a group of prohibition circuits to the OR circuit is known. The described device is characterized in that the 10 counter of the binary multiplier result consists of coarse and accurate counters, and the input terminal of the device is connected to the coarse counter input through one prohibition circuit and to reset the counter of the exact counter connected to the output of the circuit "OR. This improves the accuracy of the device. FIG. 1 shows a diagram of the device; 20 in FIG. 2 - time diagram. The device consists of a binary multiplier /, containing coarse and accurate counters 2 and 3, counter 4, prohibition circuit 5 and circuit 6 of the reference frequency generator 25, 7 trigger 8 and prohibition circuits 9, 10 and //. The input 12 receives the measured signal. The device works as follows. The trigger 8 is reset, with the inhibit pattern 9 open, 30 and the inhibit pattern 10 to 11 close. The first impulse arriving at input 12 places in code 4 the code defining the measurement time T and transfers trigger 8 to the position in which the inhibitory circuits 10 and 11 open. A generator 7 is connected to the input of counter 4 with a pulse frequency FO -. After the measurement time T L O-To, the pulse from the output of the counter 4 transfers the trigger 8 to the initial state, and the measurement process ends. During time T in counter 3, N - pulses of unknown frequency will be counted. T + o is the time interval (see fig. 2), where / o is the time interval formed due to the discrepancy between the measurement end pulse and the measured frequency pulse. Convert this expression: 1. G, t TTx whence F (N, + F, f.),

As is known, the frequency of the signal at the output of the binary multiplier / is determined by the expression

0

N,

f,

2 "

where n is the number of bits in the counter 4;

N is the code of the number recorded in counters 2 and 3.

Each pulse of unknown frequency counter 2 is reset to zero. The code generated in counter 2 is determined by the following equation:

about

N, - (N, .2 + N,} df,

From here you can get the code

.t.

2 "

N N,

-.t 2P

The decomposition of function I in the NI T-Fx expression series shows that the device described calculates, to refine the result of the conversion, the terms of higher order terms than the known device.

Subject invention

A frequency-code type matching device containing a prohibition circuit, a reference frequency generator connected to a binary multiplier that includes a result counter, connected through a prohibition circuit group

to the scheme "OR, characterized in that, in order to improve the accuracy of work, therewith, the binary multiplier result counter consists of coarse and precise counters, and the input terminal of the device through

one barring circuit is connected to the input of the coarse counter and to the reset circuit of the counter of the exact counter, the input of which is connected to the output of the OR circuit through another barring circuit.

.12

ten