SU1563766A1 - Apparatus for automatic control of centrifuge - Google Patents

Abstract

The invention relates to a technique for controlling electric centrifuge with short-term action. The purpose of the invention — improving noise immunity — is achieved by additionally introducing a low-pass filter, an RS trigger, an I element, a Start bus, and a synchronization unit connected to the auxiliary winding of the mains transformer. 2 Il.

Description

The invention relates to a technique for controlling electric centrifuge with short-term action.

The purpose of the invention is to improve noise immunity.

FIG. 1 shows a block diagram of a centrifuge automatic control device; in fig. 2 is an electrical diagram of a synchronization unit.

The centrifuge automatic control device contains an intensity setting device 1, a centrifuge 2 with a rotational speed pulse sensor 3 and a current sensor 4, a regulator 5 connected to a power converter 6 and a current sensor 4. In addition, the device is additionally equipped with a low-frequency filter 7, an RS-trkgger 8, an element 9, a 10-start bus, a synchronization unit 11 that is connected to the auxiliary winding 12 of the power transformer 13. The device also includes a power block 14 containing low-frequency filter 7 and the rectifier 15. The output of the synchronization unit C is connected to the first input of the element and 9, the output of which is connected to the input of the intensity setpoint 1 and the RS input-flip-flop 8, the output of which is connected to the second input of the element 9. At that S-input trigger 8 connect a bus 10 "Start, low-frequency filter 7 is coupled to the input of the power converter 6 and the setting unit 1 and the intensity of the pulse encoder 3, the rotational speed are connected to the inputs of the regulator 5.

The synchronization unit 11 contains an operational amplifier 11.1, a limiting resistor 11.2, a diode 11.3, and a zener diode 11.4.

The device works as follows.

In the initial state, the output of the / 5-trigger 8 is in the state "O. The synchronization unit 11 generates network zero pulses at which the power supply ripples are minimal. When a command is received from the bus 10, the Start # 5-trigger 8 is set to the state "1, preparing the element AND 9 for actuation. At the moment when the pulse AND to the other input of the element 9 comes from the output of the synchronization unit 11, an intensity setpoint 1 start pulse appears , simultaneously setting the RS-flip-flop 8 to the initial state. From the output of the intensity setting device 1, the driving signal is fed to the input of the controller 5, where it is compared with the signal of the actual rotation frequency of the centrifuge 2 taken from the pulse sensor 3 of the rotation frequency and with the actual value of the current of the centrifuge motor 2 taken from the current sensor 4. The control signal is then fed to the input of a power converter 6, the output of which determines the rotational speed of the centrifuge motor 2.

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The synchronization unit 11 operates in a signal limiter amplifier mode for normalizing the latter for the purpose of interfacing with the element base of the device, automatic centrifuge control (K155 IC).

The process of applying the material by centrifuging is carried out at high (up to 10,000 rpm) rotational frequencies with maximum (up to 50,000 rpm / s) acceleration. In this case, the formation of a layer of applied material is completed in a few revolutions of the centrifuge. The most important requirement for this is the reproducibility of the rotation parameters of the centrifuge, since the thickness and stability of the layer of the applied material depends on it from cycle to cycle. When synchronizing the start-up time of the centrifuge with the moment of minimum and constant ripple, the voltage of the power source achieves a high reproducibility of the thickness of the formed layer of the applied material from cycle to cycle.

Claims (1)

Invention Formula A centrifuge automatic control device containing an intensity setter, a centrifuge with a pulse rotational speed sensor and a current sensor, a controller associated with a power converter and a current sensor, characterized in that, in order to improve noise immunity, it is additionally equipped with a low frequency filter, RS- a trigger, an And element, a Start-up bus and a synchronization unit connected to the auxiliary winding of the mains transformer, the output of the synchronization unit being connected to the first input of the And element, the output the latter is connected to the input of the intensity setting unit and to the input of the tf-S flip-flop, the output of which is connected to the second input of the And element, while the S input / 5-flip-flop is connected to the Start bus, low-frequency filter 0 is connected to the input of the power converter, and the intensity setter and the rotational frequency impulse sensor are connected to the controller inputs.  Ljnza sffr TkiT1-1 /// 12 I 7L ft. 2 UA YAZZH ZS I ttaffx.ysj.9