Automatic frequency control of voltage-controlled oscillators

Optical-capacitive coupling is used for isolation of control voltages, such as the high-voltage level of a klystron control electrode that is not referenced to ground, to serve as error voltages referenced to system ground so that the magnitude and sense of correction may be transferred

Low voltage to high voltage level shifter and related methods

A shifter circuit comprises a high and low voltage buffer stages and an output buffer stage. The high voltage buffer stage comprises multiple transistors arranged in a transistor stack having a plurality of intermediate nodes connecting individual transistors along the stack. The transistor stack is connected between a voltage level being shifted to and an input voltage. An inverter of this stage comprises multiple inputs and an output. Inverter inputs are connected to a respective intermediate node of the transistor stack. The low voltage buffer stage has an input connected to the input voltage and an output, and is operably connected to the high voltage buffer stage. The low voltage buffer stage is connected between a voltage level being shifted away from and a lower voltage. The output buffer stage is driven by the outputs of the high voltage buffer stage inverter and the low voltage buffer stage

A Novel Floating High-Voltage Level Shifter with Pre-Storage Technique

This paper proposes a novel floating high-voltage level shifter (FHV-LS) with the pre-storage technique for high speed and low deviation in propagation delay. With this technology, the transmission paths from input to output are optimized, and thus the propagation delay of the proposed FHV-LS is reduced to as low as the sub-nanosecond scale. To further reduce the propagation delay, a pull-up network with regulated strength is introduced to reduce the fall time, which is a crucial part of the propagation delay. In addition, a pseudosymmetrical input pair is used to improve the symmetry of FHV-LS structurally to balance between the rising and falling propagation delays. Moreover, a start-up circuit is developed to initialize the output state of FHV-LS during the VDDH power up. The proposed FHV-LS is implemented using 0.3-µm HVCMOS technology. Post-layout simulation shows that the propagation delays and energy per transition of the proposed FHV-LS are 384 ps and 77.7 pJ @VH = 5 V, respectively. Finally, the 500-points Monte Carlo are performed to verify the performance and the stability

New approach for estimation of incident energy on high voltage level

Abstract The purpose of this paper is to show a new calculation model, which is able to calculate the incident energy in any places near an electric arc in case of high voltage, without neglecting of length and position of the electric arc. This method is developed especially for the electric transmission network above 35 kV and several meters of gap distances. It would be used to estimate the thermal load of a power line worker close an initiated electric arc during live-line maintenance by bare-hand and hot stick method as well

Electrooptic Methods for Measurement of Small DC Currents at High Voltage Level

Two electrooptic methods for measurement of DC currents at high voltage level, extending from the nA range and up to the milliampere range have been developed. First, by switching the polarity of a measured DC voltage into a Pockels cell, DC currents can be measured and transmitted along an optical fibre to an electrooptic converter. Second, by use of an electronic circuit the measured signal can be converted into a modulated frequency form for transmission along an optical fibre. These systems are described, measurement results are presented and improvements to be made in the future are outlined. The measuring methods can be used both for development and supervision of electrical insulating systems. For DC measurements a system wherein the voltage is applied (across the Pockels cell) not directly but via an electrooptic circuit was developed. This circuit periodically inverts the polarity of the voltage across the cell, effectively applying a square wave voltage with amplitude equal to the DC voltage to be measured. The switching circuit is based around two high voltage transistors TA, TB, with the Pockels cell electrodes being each connected to one of the transistor collectors. The transistor collectors are connected via resistors RA and RB to the protective side of the voltage to be measured and the emitters to the negative side. The currents flowing in to the bases of the transistors are independently controlled by the light levels following on the two photodiodes PDA, PDB

Characterization of Large Volume 3.5 x 8 inches LaBr3:Ce Detectors

The properties of large volume cylindrical 3.5 x 8 inches (89 mm x 203 mm) LaBr3:Ce scintillation detectors coupled to the Hamamatsu R10233-100SEL photo-multiplier tube were investigated. These crystals are among the largest ones ever produced and still need to be fully characterized to determine how these detectors can be utilized and in which applications. We tested the detectors using monochromatic gamma-ray sources and in-beam reactions producing gamma rays up to 22.6 MeV; we acquired PMT signal pulses and calculated detector energy resolution and response linearity as a function of gamma-ray energy. Two different voltage dividers were coupled to the Hamamatsu R10233-100SEL PMT: the Hamamatsu E1198-26, based on straightforward resistive network design, and the LABRVD, specifically designed for our large volume LaBr3:Ce scintillation detectors, which also includes active semiconductor devices. Because of the extremely high light yield of LaBr3:Ce crystals we observed that, depending on the choice of PMT, voltage divider and applied voltage, some significant deviation from the ideally proportional response of the detector and some pulse shape deformation appear. In addition, crystal non-homogeneities and PMT gain drifts affect the (measured) energy resolution especially in case of high-energy gamma rays. We also measured the time resolution of detectors with different sizes (from 1x1 inches up to 3.5x8 inches), correlating the results with both the intrinsic properties of PMTs and GEANT simulations of the scintillation light collection process. The detector absolute full energy efficiency was measured and simulated up to gamma-rays of 30 Me

Stochastic Method for Measurement of Voltage and Current at High Voltage Level

У раду je обрађен проблем мерења високог напона и струје у несинусидалној високонапонској мрежи, стање технике, предлог решења које подразумева неконвенционални начин мерења ових величина, практично израђен прототип и извршена потребна мерења која су потврђена теоријски. Мерење напона у високонапонској мрежи се врши напонским мерним трансформатором без језгра и интегрисаним мерилом хармоника (IMH), а затим се стохастичком методом мере хармоници напона, смерови и протоци снаге, односно енергије. За мерења струје на високом напону предлаже се калем Роговског и стохастичка метода мерења. Стохастичка метода мерења је заснована на додавању дитерског случајног сигнала на мерени сигнал. Сметње и присуство виших хармоника у мрежном сигналу су, за ову методу, додатни дитерски сигнали који методи не смањују тачност мерења.U radu je obrađen problem merenja visokog napona i struje u nesinusidalnoj visokonaponskoj mreži, stanje tehnike, predlog rešenja koje podrazumeva nekonvencionalni način merenja ovih veličina, praktično izrađen prototip i izvršena potrebna merenja koja su potvrđena teorijski. Merenje napona u visokonaponskoj mreži se vrši naponskim mernim transformatorom bez jezgra i integrisanim merilom harmonika (IMH), a zatim se stohastičkom metodom mere harmonici napona, smerovi i protoci snage, odnosno energije. Za merenja struje na visokom naponu predlaže se kalem Rogovskog i stohastička metoda merenja. Stohastička metoda merenja je zasnovana na dodavanju diterskog slučajnog signala na mereni signal. Smetnje i prisustvo viših harmonika u mrežnom signalu su, za ovu metodu, dodatni diterski signali koji metodi ne smanjuju tačnost merenja.A problem of measurement of high voltage and current in non-sinusoidal grid is given in the thesis, along with the current state in the field, the proposed non-conventional measurement method for these values, the realized prototype and the necessary measurement results that are confirmed theoretically. Measurement of voltage in high-voltage grid is performed using the coreless high voltage transformer and the Integrated harmonic measurement device (IMH). The stochastic method is used to measure harmonics of voltage, direction and flow of power and energy. For current measurement at high voltage level a Rogowski coil along with the Stochastic measurement method is proposed. Stochastic measurement method is based on adding a arbitrary dither signal to the measured signal. Disturbances and pollution of the grid signal are, for this method, additional dither signals that do not lower the measurement accuracy

Stochastic Method for Measurement of Voltage and Current at High Voltage Level

У раду je обрађен проблем мерења високог напона и струје у несинусидалној високонапонској мрежи, стање технике, предлог решења које подразумева неконвенционални начин мерења ових величина, практично израђен прототип и извршена потребна мерења која су потврђена теоријски. Мерење напона у високонапонској мрежи се врши напонским мерним трансформатором без језгра и интегрисаним мерилом хармоника (IMH), а затим се стохастичком методом мере хармоници напона, смерови и протоци снаге, односно енергије. За мерења струје на високом напону предлаже се калем Роговског и стохастичка метода мерења. Стохастичка метода мерења је заснована на додавању дитерског случајног сигнала на мерени сигнал. Сметње и присуство виших хармоника у мрежном сигналу су, за ову методу, додатни дитерски сигнали који методи не смањују тачност мерења.U radu je obrađen problem merenja visokog napona i struje u nesinusidalnoj visokonaponskoj mreži, stanje tehnike, predlog rešenja koje podrazumeva nekonvencionalni način merenja ovih veličina, praktično izrađen prototip i izvršena potrebna merenja koja su potvrđena teorijski. Merenje napona u visokonaponskoj mreži se vrši naponskim mernim transformatorom bez jezgra i integrisanim merilom harmonika (IMH), a zatim se stohastičkom metodom mere harmonici napona, smerovi i protoci snage, odnosno energije. Za merenja struje na visokom naponu predlaže se kalem Rogovskog i stohastička metoda merenja. Stohastička metoda merenja je zasnovana na dodavanju diterskog slučajnog signala na mereni signal. Smetnje i prisustvo viših harmonika u mrežnom signalu su, za ovu metodu, dodatni diterski signali koji metodi ne smanjuju tačnost merenja.A problem of measurement of high voltage and current in non-sinusoidal grid is given in the thesis, along with the current state in the field, the proposed non-conventional measurement method for these values, the realized prototype and the necessary measurement results that are confirmed theoretically. Measurement of voltage in high-voltage grid is performed using the coreless high voltage transformer and the Integrated harmonic measurement device (IMH). The stochastic method is used to measure harmonics of voltage, direction and flow of power and energy. For current measurement at high voltage level a Rogowski coil along with the Stochastic measurement method is proposed. Stochastic measurement method is based on adding a arbitrary dither signal to the measured signal. Disturbances and pollution of the grid signal are, for this method, additional dither signals that do not lower the measurement accuracy