Bucket regulator

But as soon as we put in a capacitor, we now also need to limit the inrush current into it — all capacitors connected directly across a dc source, will exhibit this uncontrolled inrush — and that can t be good either for noise, EMI, or for efficiency. Of course we could simply opt for a resistor to subdue this inrush, and that in fact was the approach behind the early bucket regulators (Figure 1-2). 

But we still need to limit the capacitor charging current ( inrush current ). And as indicated, we could use a resistor. That was in fact the basic principle behind some early linear-to-switcher crossover products like the bucket regulator shown in Figure 1-2. 

Note also that in either of these RC-based bucket regulator implementations, the switch ultimately ends up being toggled repetitively at a certain rate — and in the process, a rather crudely regulated stepped down output dc rail is created. By definition, that makes these regulators switching regulators too ... 

Though the detailed functioning of the modern buck regulator of Figure 1-2 will be explained a little later, we note that besides the obvious replacement of R with an L, it looks very similar to the bucket regulator — except for a mysterious diode. The basic principles of power conversion will in fact become clear only when we realize the purpose of this diode. This component goes by several names — catch diode, freewheeling diode, commutation diode, and output diode, to name a few But its basic purpose is always the same — a purpose we will soon learn is intricately related to the behavior of the inductor itself. 

Fig. 3—Oil droplets move perpondicu ar to di ection o watv flow in horizontal skimmers, enhancing efficiency. Height of oil troth is regulated with interface controller or bucket and we>r design...

The classic pressure-drop experiment is performed on an apparatus like that shown in Fig. 6.1, In this experiment we set the flow of the fluid with the flow-regulating valve. We measure the flow rate with the bucket and stop watch. At steady state we read pressure gauges and P2 and record their difference. Usually we are interested in the pressure drop per unit length, so we divide the pressure drop by distance Ax (the length of the test section) and plot (Pj - P2) /Ax versus volumetric flow rate Q. 

The use of personal vehicles, company or institutional vehicles (including airplanes), and customer vehicles for transporting regulated materials, which may be hazardous, is a serious concern. Most businesses and academic institutions forbid the use of privately owned personal vehicles, due to the serious insurance consequences if an accident occurs. Most individuals will find that their personal vehicle insurance does not cover them when they are transporting hazardous materials. Anyone who needs to transport regulated materials personally between buildings within an institution should walk. (Secondary containment, such as a rubber bucket, should always be used for carrying bottled chemicals.)... 

Another type of automatic sampler is the Woodside sampler, which consists of chains carrying small cups (Figure 13.6). The chains pass through the grain stream, the buckets fill and empty directly into a hopper, from which the sample can be transported by gravity pneumatically or manually into the test laboratory. The size of sample delivered by a Woodside sampler can be regulated by the number and size of the cups. The modern tendency is to move toward the diverter-type sampler. These are generally more flexible than the Woodside sampler. For example, peas are very hard and more or less round, and tend to bounce into and out of the small cups of a Woodside sampler. Diverter samples are not subject to this source of error. 

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