The High-Voltage Power Supply

A typical commercial HVPS is shown in Fig. 1.7. The front panel has an indicator light that shows whether the unit is on or off and, if it is on, whether the output is positive or negative voltage. There are two knobs for voltage adjustment, one for coarse changes of 500-V intervals, the other for changes of 

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The excitation of the analytical lines depends approximately on the square of the x-ray tube voltage (1.5) and is therefore very sensitive to the regulation of the high-voltage power supply. The performance of the other components of the x-ray spectrograph is not so sensitive to power supply regulation. It is usually convenient to regulate the entire power supply to the instrument because the x-ray tube is the major part of the load. 

Input power is not the energy consumption at the discharge-gap, but the presented value on the high-voltage power supply. Results show that type A electrodes offer the highest ener efficiency (LHV, 30.2% HHV, 30.8%). For that reason, the pair of coaxial needle type of electrodes was selected for subsequent experiments. 

The high-voltage power supply and related open connections should be handled with extreme care to avoid electrical shock. Nitroaromatic explosives are toxic and mutagenic compounds and should be handled with extra care. Skin and eye contact and accidental ingestion or inhalation should be avoided. 

One key feature of CE is the overall simplicity of the instrumentation. Briefly, the ends of a narrow-bore, fused silica capillary (25-75 pm i.d., 350-400 pm o.d., and 10-100 cm in length) are placed in buffer reservoirs. The content of the reservoirs is identical to that within the capillary. The reservoirs also contain the electrodes used to make electrical contact between the high voltage power supply and capillary. The sample is loaded into the capillary as follows one of the reservoirs (usually at the anode) is replaced by the sample reservoir and either an electric field (electrokinetic... 

Yan et al. [27] manufactures an instrument, which can be operated in both CEC and micro-HPLC mode. The high voltage power supply can provide up to 60 kV. A stainless-steel six-port rotary valve that also includes an injection port serves as the injection manifold, which is inserted in the electric circuit. The instrument is partially housed within a Faraday cage. 

Field emission cathodes were examined in the long duration mode for 10 hours under fixed value of current 50 pA. The test objective was in stabilization of the emission current value by means of the high-voltage power supply. During the experiment measurements of voltage, supplied on equipment, and emission were performed every second. 

There are two types of corona assemblies, those that contain a corona wire and those that contain a corona roller. The corona wire is a small diameter wire that is charged by the high-voltage power supply. The wire is located in a special notch in the floor of the laser printer (underneath the EP print cartridge). The corona roller performs the same function as the corona wire, except that it s a roller rather than a wire. Because the corona roller is directly in contact with the paper, it supports higher speeds. It is for this reason that the corona wire isn t used in laser printers much any more. 

A. The high-voltage power supply is the part of both EP process and HP LaserJet process printers that supplies the voltages for the charge and transfer corona assemblies. 

A, E. Since the laser printer is printing pages that are all black and replacing the toner cartridge has no effect, the probable cause of this problem is the high-voltage power supply (HVPS) is bad. 

Electrodes. These components are generally platinum wires which serve as the contact point between the liquid (buffer solutions) in the system and the high-voltage power supply. An inert metal is desirable to avoid an electrochemical reaction or excessive fouling of the electrode surface that would disrupt current flow in the system. 

Figure 3.4. The overall view of a powder diffractometer. The radiation enclosure is opened to expose the goniometer, which rests on top of the high voltage power supply. The computer on the right is used to manage and control data collection and to carry out preliminary processing of the data, e.g. conversion from a software-specific binary to ASCII format. (Courtesy of Scintag, Inc.) ...

The high-voltage power supply, amplifier-discriminator, and scalers were homebuilt (5, 7). During the operation of the detector, propane counting gas was mixed with the helium carrier gas in a 4 1 ratio, and the total combined helium and propane flow rate was maintained at 125 cm min" (NTP). With 2 in. of lead shielding, the typical counter background level was 100-200 cpm. 

Fig. 7.56 Effect of a broken ground return path to the high voltage power supply...

Commercially available systems integrate in a single unit the high-voltage power supply, amplifier, analog-to-digital converter (ADC) and multichannel analyzer with the counting chamber, detector, and preamplifier, as shown in Fig. 8.8. 

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