Speed control automatic

Automatic speed control of slip-ring motors 5/95... 

By makitig the electrodes move through ti geared motor, it is possible to tiehieve even automatic speed control of slip-ring motors through such starters. 

Good range. Relatively good low speed efficiency. Automatic speed control easy Low cost. Can use squirrel cage induction motor. Automatic control easy... 

A recent trend is to introduce different in-vehicle driver support systems to reduce the mental load of the driving task. These include, for example, automatic speed control, anti-collision radar, anti-lock braking system (ABS)... 

The governor can be set to make the machine run at a constant speed, even on load variations, with extremely quick and almost instantaneous speed control, and thus maintain a near-zero AN. In a parallel operation they can also control load sharing automatically and accurately. Power grids, receiving power from different sources, are extremely susceptible to frequency variations. Even a small Af of the order of 0.5 Hz, may cause the system to trip. A fast-actuating governor with low response time (as low as 0.5 second) can overcome such a situation by quickly regulating the speed of the PM. 

A starter or contactor with manual push-button or thermostatic operation to start and stop the fan normally controls simple systems. More complex systems that incorporate components that need control or monitoring are normally operated from purpose-built central control panels. The most common functions provided are fan motor stop, start and speed control, damper control, filter-condition indication and heater battery control. For optimum control, the system should be automatically controlled from thermostats or other sensors and a timeswitch. 

The wide application of hydraulic systems has undoubtedly been stimulated by the increasing use of fully automatic controls for sequences of operations where the response to signals must be rapid and the controls themselves light and easily operated. These needs are met by hydraulic circuits that, in addition, provide infinitely variable speed control, reversal of high-speed parts without shock, full protection against damage from overhead and automatic lubrication. 

With air-cooled condensers and water cooling towers it is possible to reduce the air flow hy automatic dampers, fan speed control, or switching off fans, where two or more drives are fitted. The control should work from pressure hut can he made to work from temperature (see Section 6.12). 

Motor-driven compressors usually operate at constant speed, and other methods of controlling the capacity are necessary. On reciprocating compressors discharging into receivers, up to about 75 kW (100 hp), two types of control are usually available. These are automatic-start-and-stop control and constant-speed control. 

In order to facilitate repeated aspiration, an automatic system for the process was required (4). A Braun tube was connected to the aspiratoscope through the camera, so that the operator can handle the microscope by watching the Braun tube instead of looking through the ocular of the microscope. In this automatic system, determination of the position of the capillary tip and aspiration of the cell contents can be operated with buttons on the controller (Fig. 2). There is another button on the control panel to operate a cursor, which moves on the Braun tube. A joy stick circuit ( table JS-1 ), moves the stage to eight horizontal levels at variable speeds controlled with the table speed VR 1 button. Another joy stick circuit, cursor JS-2 , moves the cursor on the Braun tube to eight horizontal levels at variable speeds controlled with cursor speed VR 2 . The capillary tube is moved vertically by the up/down switch at variable speeds controlled with capillary speed VR 3 . 

It has been stated (J.S.D.C., 1968, 84, 66) that the productivity of one man looking after a group of five high pressure dyeing machines was increased by 37 per cent by the introduction of automatic process control. The reason is that there are a number of occasions when more than one operation should be carried out simultaneously and this cannot be done manually. Another factor is the human inability to move and react mentally with instantaneous speed. Many more examples could be quoted to demonstrate the advantage of the elimination of human memory and manual manipulation in the operation of dyeing processes. 

The KS-87B camera is in the Department of Defense inventory. It is a pulse-operated frame camera with a high-speed focal plane shutter, integral automatic exposure control and data recording, and forward... 

Paul Troester started manufacturing single-screw extruders (SSE) in 1892, but only in 1935 the first SSE for thermoplastics was introduced. Four years later, Paul Leistritz built electrically heated, air cooled SSE, having L/D = 10, automatic temperature control, variable screw speed, and nitrided barrel. The machine is considered prototype of the modem extmders. The SSE offered continuous processing capability, but it was notoriously poor as a mixer. Furthermore, under the standard processing conditions, a significant non uniformity in the shear history had resulted in large temperature differences of the melt, AT = 60°C. To alleviate the... 

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