Voltage, pulsed

By locating the anode entirely upstream from the ionized gas volume, collection of long range beta particles is minimized in the displaced coaxial cylinder design, and the direction of gas flow minimizes diffusion and convection of electrons to the collector electrode. However, the free electrons are sufficiently mobile that modest pulse voltages (e.g., 50 V) are adequate to cause the electrons to move against the gas flow and be collected during. this time. 

Fig. 1. Schematic diagram of the multimass ion imaging detection system. (1) Pulsed nozzle (2) skimmers (3) molecular beam (4) photolysis laser beam (5) VUV laser beam, which is perpendicular to the plane of this figure (6) ion extraction plate floated on V0 with pulsed voltage variable from 3000 to 4600 V (7) ion extraction plate with voltage Va (8) outer concentric cylindrical electrode (9) inner concentric cylindrical electrode (10) simulation ion trajectory of m/e = 16 (11) simulation ion trajectory of rri/e = 14 (12) simulation ion trajectory of m/e = 12 (13) 30 (im diameter tungsten wire (14) 8 x 10cm metal mesh with voltage V0] (15) sstack multichannel plates and phosphor screen. In the two-dimensional detector, the V-axis is the mass axis, and V-axis (perpendicular to the plane of this figure) is the velocity axis (16) CCD camera.

The radiation detector is located some distance from the readout. A shielded coaxial cable transmits the detector output to the amplifier. The output signal of the detector may be as low as 0.01 volts. A total gain of 1000 is needed to increase this signal to 10 volts, which is a usable output pulse voltage. There is always a pickup of noise in the long cable run this noise can amount to 0.001 volts. 

The steam power plant should become another site for an exciting project enabling a 2-fold reduction in the degree of flue gas cleaning while cutting the electric power consumption by a factor of 2 to 3. The new process that applies pulsed voltage to the precipitation filters has been successfully introduced at several other plants in Ukraine. 

Electrochemical detectors, which are based on the electrochemical oxidation or reduction of the analyte, can be applied to the analysis of selected compounds such as phenols. It is physically simple, but is very sensitive for catecholamines. However, the adsorption of reacted molecules on the surface of the electrodes can reduce the conductivity. To overcome this problem a pulsed voltage is applied, which cleans the electrode surface between measurements. This pulsed amperometric detection is also sensitive for carbohydrates. 

Vsq - A square wave voltage source. This source uses the pulsed voltage source to make a square wave. It is a special case of Vpulse. 

The length of the simulation is 9 ms. The pulse will start at zero volts and remain there for 3 ms, then go to 5 V for 3 ms, and then return to 0 for another 3 ms. To create this waveform we can use either a pulsed voltage source (VPULSE) or a piecewise linear voltage source (VPWL). For this example we will use the VPWL source. To edit the attributes of the PWL... 

S0LUTI0I1 Use the pulsed voltage source. Set the rise and fall times to 1 ps so that the rise and fall times are much shorter than the pulse width and period of the square wave. Wire the circuit ... 

In this section we will demonstrate the use of an ideal operational amplifier and the pulsed voltage waveform. Wire the circuit shown below. 

The pulsed voltage source can be used to create an arbitrary pulse-shaped waveform. We will use it to create a 1 kHz square wave. The rise and fall times of the square wave will be 1 ps. Double-click the LEFT mouse button on the pulsed voltage source graphic, <0, to obtain its spreadsheet and edit its attributes ... 

RISE TIME - The amount of time the voltage source takes to go from the initial voltage to the pulsed voltage, in seconds. 

We would like to create a 5 V square wave at a frequency of 1 kHz. The rise and fall times will be 1 ps. We will specify the following values for the attributes Period = lm, rise time = lu, fall time = lu, pulse width = 0.5m, initial voltage = 5, pulsed voltage = -5, delay time = 0. A few of these settings are shown in the spreadsheets below ... 

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 ... 

We see that the pulse width is 1 pis and the period is 50 pis long to let the capacitor come into steady state after the pulse. Note that we are simulating the circuit for only one period. We could have used the PWL source, but the pulsed voltage source is easier to set up. Run the simulation and then run Probe. We will first look at the input to see if the pulse is correct Add the trace V (VIN) ... 

The value of the gain is now the value of the parameter FB galn. We would like the input to be a 0 to 5 V step input. The step will be 0 for the first second and then 5 V for the remainder of the simulation. This waveform can be constructed with a pulsed voltage source. Set the attributes of the VPULSE source as shown. On your screen, the attributes will be arranged in alphabetical order. I have changed the order in my screen so that you can see all of the parameters you need to specify ... 

II pulse width[pulsed voltage RISEJTIME INITIAL.VOLTAGE PERIOD DELAYTIME FALL TIME... 

This summing circuit is used in polarography and voltammetry to superimpose AC, SW or pulse voltage to DC applied voltage. 

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