Inverter rise time

Viscosity can also be determined from the rising rate of an air bubble through a Hquid. This simple technique is widely used for routine viscosity measurements of Newtonian fluids. A bubble tube viscometer consists of a glass tube of a certain size to which Hquid is added until a small air space remains at the top. The tube is then capped. When it is inverted, the air bubble rises through the Hquid. The rise time in seconds may be taken as a measure of viscosity, or an approximate viscosity in mm /s may be calculated from it. In an older method that is commonly used, the rate of rise is matched to that of a member of a series of standards, eg, with that of the Gardner-Holdt bubble tubes. Unfortunately, this technique employs a nonlinear scale of letter designations and may be difficult to interpret. 

Click the OK button when you have made the changes to return to the schematic. The input to the inverter will be a short 1 ps pulse. The attributes of the pulsed voltage source are Period = 50u, rise time = In, fall time = In, Pulse width = lu, initial.voltage = 0, Pulsed voltage = 5, delay.time = lu. Double-click the LEFT mouse button on the pulsed voltage source graphic to obtain the spreadsheet for the source ... 

The Performance Analysis capabilities of Probe are used to view properties of waveforms that are not easily described. Amplifier bandwidth, rise time, and overshoot are examples. To calculate the bandwidth of a circuit, you must find the maximum gain, and then find the frequency where the gain is down by 3 dB. To calculate rise time, you must find the 10% and 90% points, and then find the time difference between the points. The Performance Analysis gives us the capability to plot these properties versus a parameter or device tolerances. The Performance Analysis is used in conjunction with the Parametric Sweep to see how the properties vary versus a parameter. The Performance Analysis is used in conjunction with the Monte Carlo analysis to see how the properties vary with device tolerances. In this section we will plot the rise time of a BJT inverter versus the value of the collector resistor. See Section 9.G to leam how to use the Performance Analysis in conjunction with the Monte Carlo analysis. 

Liquid Displacement Gas Meter Provers. The Hquid displacement prover is the most prevalent standard for the caHbration of flow meters at low to moderate gas flow rates. The method consists of displacing a known volume of Hquid with gas (Fig. 2). Gas entering the inverted beU causes it to rise and a volume increment can be timed. Typical prover capacities are 1 m or less although capacities as large as 20 m are available. Accuracies can be on the order of 0.5% of actual flow rate. 

This process does not lead to net ozone depletion because it is rapidly followed by reaction 2, which regenerates the ozone. Reactions 2 and 3 have, however, another important function, namely the absorption of solar energy as a result, the temperature increases with altitude, and this inverted temperature profile gives rise to the stratosphere (see Figure 1). In the lower layer, the troposphere, the temperature decreases with altitude and vertical mixing occurs on a relatively short time scale. In contrast, the stratosphere is very stable towards vertical mixing because of its inverted temperature profile. 

A method similar to the falling-ball method is the bubble method. A vial is filled with liquid, leaving sufficient room for a bubble that can equal the diameter of the vial. The vial is inverted and the time required for the bubble to pass two predetermined marks is determined. The viscosity will be directly proportional to the time required for the bubble to rise. 

When designing digital circuits we are usually concerned with the rise and fall times of the design, given device tolerances. The example given here is for a CMOS inverter, but the procedure used can be applied to any switching circuit with device tolerances. Wire the circuit below ... 

EXEHC1SE 9-0 Find the minimum and maximum rise and fall times for the BJT inverter studied in Section 6.K. Let the resistors have 20% Gaussian distributions and let have a uniform distribution from 50 to 350. Start with the circuit from Section 6.K, but use the 5% resistor model and the 2n3904 BJT model (R5pcnt and Q2n3904) ... 

He inverted the tube in a pool of mercury. Torricelli noticed that the mercury in the tube fell, creating a vacuum at the top of the tube. The final height of the mercury in the tube was roughly 28 inches. Because mercury has 13.5 times the density of water, Torricelli proposed that water should rise about 13.5 X 28 inches or about 32 feet. Torricelli reasoned that atmospheric pressure placed a limit on how high a liquid could raise in the tube. His inverted mercury-filled tube was the first barometer (Figure 9.1). 

In a 250-00. Erlenmeyer flask provided with a two-holed stopper which has a slit cut in one edge to serve as an air vent and which holds a thermometer, the bulb of which reaches almost to the bottom of the flask, is placed 31.5 g. (0.5 mole) of anhydrous nitric acid (Note 1). The flask is cooled below io° in ice-water, and 51 g. (0.5 mole) of acetic anhydride (Note 2) is slowly added from a buret through the second hole in the stopper in portions of about 0.5 cc. at a time. The temperature of the reaction mixture is never allowed to rise above io° (Note 3). After about 5 cc. of the acetic anhydride has been added the reaction becomes less violent, and larger portions, increasing gradually from 1 to 5 cc., may be introduced at a time with constant shaking. After all the acetic anhydride has been added, the stopper and the thermometer are removed. The neck of the flask is wiped clean with a towel, and the flask is then covered with an inverted beaker and allowed to come up to room temperature in the original ice bath (Note 4). 

The conventional wisdom was that the system functioned because the generation of the pyridine gave rise to an oily species, which provided the adhesive component of the coating. On one occasion my technician, inverted the ratio of dihydropyidine and HABI, and found that the unexposed areas toned, but not the exposed areas. Clearly something was counter to our comprehension of the system. I repeated the experiment several times, but was never able to postulate a satisfactory mechanism for this. 

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