SU842583A1 - Device for rotation speed monitoring - Google Patents

Description

(54) DEVICE FOR SPEED CONTROL

-, -.-, -. .-l. ROTATIONS

and on the perforated rotating disk there is an additional control element, against which an additional electromagnetic sensor is placed, the output of which is connected to the input of the time interval generator and the reset inputs of the counter and trigger, the time interval generator outputs are connected to the third inputs of the output elements And, the time interval generator contains time zadachkhtsiy element made on the integrating operational amplifier, the output of which is connected through an amplitude comparator with one input of an RS flip-flop, whose direct output through two parallel-connected circuits of a series-connected resistor and diode is connected to the input of the time of the master element.

FIG. 1 shows the structural electrical circuit of the proposed device; in fig; 2 is a block diagram of a time interval former.

The device contains a profiled disk 1, on which an additional control element 2 is fixed: electromagnetic sensors 3 and 4, a time interval generator 5, a counting block b consisting of counter 7, element 8, trigger 9, decoder 10, and two output three-way elements And 11 and 12, from outputs 13 and 14 of which signals which go beyond the specified tolerance are taken.

Shaper time interval (Fig.2) consists of the time of the master element, performed on the operational integrating amplifier 15, resistors 16 and 17, diodes 18 and 19 and the capacitor 20, the amplitude comparator performed on the operational amplifier 21 and the RS-trigger 22.

The principle of operation of the device is as follows.

The control element 2, passing by the sensor 3, when rotating the profiled disk 1, excites in the sensor 3 an electrical impulse that simultaneously starts the driver 5 and the counting unit 6. The duration of the pulse generated at the output of the counting unit 6 corresponds to the sum of the durations of a constant number of pulses of the sensor 4 i.e. the angular duration (duty cycle) of the pulse at the output of the counting unit 6 is constant at any speeds (periods) of rotation of the profiled disk 1. The duration of the pulse generated at the output of the imaging unit 5 is proportional not only to the value of the pulse repetition period of sensor 3. (the period of rotation of the profiled disk 1 ) ;. but also the magnitude of the rate of change of these periods. The comparison of the output pulses of the imaging unit 5 and the counting unit 6 is carried out by elements 11 and 12. In the case where the rotation period of the profiled disk 1 is constant, the pulses at the outputs of the elements 11 and 12 are absent, as the pulses of the imaging generator 5 and counting Block 6 are the same, and their difference is equal to zero.

In the case when the rotation period of the profiled disk 1, for example, decreases, the duration of the output pulse of the imaging unit 5 becomes longer than the duration of the output pulse of the counting unit 6 and a comparison pulse appears at the output of the And 11 element, filled with pulses from sensor 4, the number of which depends on the difference values the pulse duration of the imaging unit 5 and the counting unit 6, i.e. the rate of change of the periods of rotation of the profiled disk 1. As the periods of rotation of the profiled disk 1 increase, comparison pulses appear at the output of the element 12, since the duration of the output pulse of the former 4 will become less than the duration of the pulses of the counting block b.

Under the action of the pulse from the output of the sensor 3, the counter 7 is set to O and the trigger 9 is turned to one. The logic unit signal from the direct output of the trigger 9 is fed to the inputs of the I.12 element and the And 8 element, allowing the output pulses of the sensor 4 to be counted by the counter 7 When the counter 7 reaches the predetermined state, the output of the decoder 10 appears a logical unit signal, which sets the trigger 9 to the zero state. The counting of pulses by the counter 7 is stopped. In the next period of pulses from sensor 3, the process of forming a pulse at the direct output of flip-flop 9 will repeat, i.e. the pulse duration at the output of the counting unit 6 is always equal to the sum of the durations of a given number of pulses read by the sensor 4.

The shaper 5 is started simultaneously with the counting unit b at the moment of arrival of the pulse from the sensor 3. In the pause between the end of the formation of the output pulse of the shaper 5 and the appearance of the next pulse, the capacitor 20 is charged through the resistor 15. The amount of charge current i is constant and determined the magnitude of the resistor is 15 and the voltage of the power supply. The charge time is T - fet, where T is the pulse period of the sensor 3, is the duration of the output pulse of the imaging unit 5.

The pulse from sensor 3 sets the RS flip-flop 22 to the unit state at the direct output. Under the action of this voltage, the capacitor 20 is recharged through the resistor 16 in the opposite direction. Recharge current yes 1, also constant. The output voltage of amplifier 15 decreases. When the voltage at the output is equal to or slightly above it, the amplifier 21 triggers and returns the trigger 22 to the zero, initial state, and again the capacitor 20 is charged through the resistor 17. The pulse duration at the output of the trigger 22 will be determined by the reload time yes capacitor 20 current i, through a resistor 16.

Thus, the pulse duration at the output of the imaging unit 5 in angular units in the portions of the period is constant over a wide range of values of the unchanging periods of the input pulses from sensor 3 and is equal to the duration of a constant number of read pulses. The duration At is set by selecting the ratio of the resistances of the resistors 16 and 17.

Suppose that the counting unit 6, according to the signal of the sensor 3, generates a pulse corresponding to a quarter of the disk rotation (a quarter of the disk teeth is read). With the help of resistor 16 and 17, the pulse duration formed by shaper 5 is set equal to a quarter of the pulse period from sensor 3. For any unchanging periods, the duration of the read and generated pulse is equal and there is no signal at the device outputs. As soon as the period of the pulses from sensor 3 begins to change, for example, to increase, the angular duration of the read pulses remains unchanged, and the angular duration of the pulses of the former 5 lags slightly behind (changes) the change in the duration at the output of the counting unit 6 due to the accumulation of voltage on the capacitor 20 occurs in the final part of the previous period of pulses from sensor 3, and the discharge (formation) in the initial part of the present. This delay is the greater, the greater the rate of change The period of the signal from the sensor 3. With the same rate of change of the period, the difference in the duration of the counting unit 6 and the imaging unit 5 in angular, units, remains constant.

Therefore, when the difference pulse is filled with pulses from sensor 4 (measurement of the difference between the durations of the read and generated pulses in angular units), the number of the latter at the output of the element is And 12

proportional to the rate of change of the period of the reference pulses or the rate of change of the period of rotation of the profiled disk 1. Similarly, when the period of rotation of the profiled disk 1 decreases, the number of impulses proportional to the rate of change of the visual period appears at the output of the And 11 element.

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Claims (2)

1. A device for controlling the rotational speed, containing a profiled rotating disk, an electro5 magnetic sensor, the output of which is connected to the first inputs of two output elements And and the first input of a counting unit consisting of an element And, an information counter, 0 input of which is connected to the output of the said AND element, diiifrarator and trigger, one input of which is connected through the decoder to the outputs of the counter bits, the forward trigger output is connected to the second input of the element five And to the second input of the first output element And, and the inverse output of the trigger is connected to the second input of the second output element I, which is intended to 0 to increase speed and accuracy, a shaper of a time interval, additional electromagnetic sensor are introduced into it, and on the perforated rotating disk an additional control element is installed, against which an additional electromagnetic sensor is placed, the output of which is connected to the input of a temporary shaper 0 interval and reset inputs of the counter and trigger, and the outputs of the time interval generator are connected to the third inputs of the output elements I. 2. The device according to claim 1, 5 or 5, in that the shaper of the time interval contains a time master element made on the integrating operational amplifier, the output of which is through Amplitude comparator is connected to one RS-flip-flop input, -the direct output of which through two parallel-connected circuits from a series-connected resistor and a diode connected to the input is the time of the master element. Sources of information taken into account in the examination 1. For the UK ABOUT  1439395, class G 1 N, 16.06.76. 2. For France of France 2209935, class G 01 G 3/00, 08/09/74. Vut.1 (Put. G