SU1204953A1 - Belt-conveyer weigher - Google Patents

Description

"

The invention relates to the field of weighing technology.

The purpose of the invention is to improve the accuracy of tuning the scales by automatically determining the division factor of the tunable frequency divider.

The drawing shows a block diagram of a belt scale.

Scales contain sensors 1 and 2 weights, speed sensor 3, speed pulse block 4, crystal oscillator 5, elements 6–10, divisor-adder 11, tunable frequency divider 12, subtractor 13, counter 14 pulses, driver 15, RS-trigger 16, trigger counters 17 and 18, button 19, dividing ratio setting unit 20, work type switch 21.

The outputs of the sensors 1 and 2 of the weight, respectively, through the elements 6 and 7 are connected to the inputs of the divider-sumator 11, the output of which is connected to the summing-up input of the subtractor 13.

The output of the crystal oscillator 5 through the element And 8 is connected to the input of the tunable frequency divider 12 and the input of the element And 9, and the output of the speed sensor 3 is connected to the input of the block 4 of speed pulses, the output of which is connected to the second input And 6 - 8.

The output of the tunable frequency divider 12 is connected via the first group of contacts of the switch 21 of the type of operation to the subtracting input of the BLP1I tatel 13, and the outputs of the divider 12 are connected to the setting inputs of the division factor 20. The inputs of the dial 20 are connected to the counting outputs of the trigger counter 17, the counting input of which is connected to the output of the element 9. The output of the trigger 13 is connected to the moving contact of the second group of contacts of the operating mode switch 21, one of the fixed contacts of which is connected to the input of the pulse counter 14 , and the second - with the input element And 10.

 The output of the driver 15 is connected to the inputs of the setting to zero of the dividers 11, 12, counters 17 and 18, and the same with the R-input R5-trigger 16, the output of which is connected to the S input, trigger counter 18, at the input of the element connected to the output

049532

And 10. The output of the R5 flip-flop 16 is connected with the second inputs of the elements And 9 and 10.

Veoi work T as follows.

5 In reisim Work output nt; frequency divider 12 is connected to the subtractive input of the subtractor 13, and the output of the subtractor is connected to the input of the counter 14 pulses.

10 Block 4 of speed pulses produces pulses of constant duration t, the frequency of which is proportional to the speed of movement of the conveyor belt. These impulses

15 periodically open the elements And 6-8 through which the pulses pass from the weight sensors 1 and 2 to the divider-adder 11, and from the generator 5 to the tunable divider 12

20 frequencies. After recalculation by a divider-adder 11 and a divider 12, the pulses arrive, respectively, at the summing and subtracting (s inputs 13.

25 When the conveyor is idling, the frequency of the pulses at the input (+) and the input (-) is the same and the counter pulses to the counter 14, the pulses of the pulse pass.

30 weights 1 and 2 increase and the frequency of the pulses at the input (+) of the subtractor 13 increases proportionally. At the counter 14, pulses begin to arrive, the number of which is proportional to 35

the mass of the displaced conveyor0

rum load.

The scale zero adjustment is performed as follows. When running. idle conveyor switch 21

 operating modes are set to the zero setting position, in which no pulses are input to the (-) subtractor 13, and the subtractor output is connected to the input of the element

. And 10. Button 19 is pressed. Shaper 15 produces a pulse, setting dividers 11 and 12, counters 17 and 18 in O, and trigger 16 - in 1. Pulses from sensors 1 and 2 of the weight come in batches to the divider-adder 11, pulses from the generator 5 through the element And 8 and the element 16 opened with the trigger 16 to the trigger counter 17, and the pulses from the subtractor 13 through the open trigger 16 ele5

ment And 10 - on the trigger counter 18.

Upon receipt on the trigger counter 18 number of pulses equal to

its capacitance K, in the code of counter 18, a pulse arises, which returns trigger 16 to the initial state. The zero setting ends there.

The duration T of the zero setting is determined by the formula

T

 n

TO

 t, 18K,

)9

e ,, i

02

K., K.

{2

the initial frequencies of the signals of the sensors 1 and 2 in the absence of long-term load on the tape; - the recalculation coefficients of the frequency dividers of the divider-adder 11, which produce a division of the frequencies b; / Tp - filling ratio

pulses at the output of the block 4 speed pulses; Tg is the period following the impulses of the speed sensor 3. During the time TC to the trigger counter 7 will receive the number of pulses, the limit of the formula

9

ir9 T, 1g

TO,

1k,

04953

where i is the frequency of the signal generator 5 ..

When setting zero, you must set this value of the coefficient K | dividing the tunable frequency divider 12, which ensures the equality of the number of pulses arriving over an arbitrary period of time i at the input of (+) video output 13

“;

(-1 t i

to:

-) t0,

and at the entrance (-). L- ir

N

TO

i0.

tt

Equate to these values and substituting the value 01/1 ;; + oz j j we obtain the value of the coefficient KI, which ensures the adjustment of the zero of the weights.

7 N, -f

 P

TO.

TO

18

2 ™ "

where is the number of binary bits

trigger counter 18. Thus, to adjust the zero of the scale, it is necessary to feed the division factor N to the master of the 20 division factors, store it and feed the tuning inputs of the tunable frequency divider 12 with a shift to the left by rows.

VNIIPI Order 8516/41 Circulation 702 Subscription

Branch PPP Patent,

Uzhgorod, Projecto st., 4

Claims (1)

CONVEYOR SCALES containing the first and second weight sensors connected to the first inputs of the first and second elements AND, the outputs of which are connected to the inputs of the divider-adder, the output connected to the summing input of the subtractor, a pulse generator connected to the first input of the third element And, the output of which is connected to the input of a tunable frequency divider, a speed sensor connected to a block of speed pulses, the output of which is connected to the second inputs of the first, second and third elements And, and the first pulse counter, from ichayuschiesya in that, in order to increase the accuracy of the balance adjustment by automatically determining the division factor of the frequency divider tunable, they introduced a pulse shaper, R5-trigger, fourth and fifth elements And, second and third pulse counters, dividing factor divider, switch and start button, and the start button through the pulse former is connected to the setting inputs 0 of the divider-adder, tunable frequency divider, second and third pulse counters and to the R-input of the K5 trigger, the S-input of which is connected to the output of the third pulse counter, and the output is to the second inputs of the fourth and fifth elements And the first input of the fourth element And is connected to the output of the third element And, and the first input of the fifth element And is connected to the first output of the switch, the second output of which is connected to the first pulse counter, and the input to the output of the subtractor, the output of the fourth element And is connected to the input of the second pulse counter, the outputs of which are connected to the inputs of the divider of the division coefficient, the outputs connected to installation inputs of a tunable frequency divider, the output of which through a switch is connected to the subtracting input of the subtractor, and the output of the fifth element And is connected to the input of the third pulse counter. SU ,,., 1204953