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High Voltage Breakdown Tester The basic idea of a breakdown voltage tester is to apply current limited high voltage to an insulator, and raise the voltage until the desired voltage test level is reached, or until a small amount (1 to 2 micro Amps) of leakage current flows. The light bulb in the primary of the high voltage transformer is an old but good method of limiting the current to the transformer primary in the event of a major component failure. Since high voltages are involved, it's necessary to build this tester with plenty of open space between components and wiring. www.realhamradio.com /High_Voltage_Breakdown_Tester.htm   (2790 words)

breakdown Breakdown is characterized by the rapid increase of the current under reverse bias. The breakdown voltage is a key parameter of high power devices but also for logic devices as one typically reduces the device dimensions without reducing the applied voltages, thereby increasing the internal electric field. Avalanche breakdown is caused by impact ionization of electron-hole pairs by carriers that have gained energy by accelerating in the high electric field in the depletion region of a reversed biased p-n diode. ece-www.colorado.edu /~bart/book/breakdown.htm   (831 words)

Reverse bias breakdown The breakdown of logic devices is equally important as one typically reduces the device dimensions without reducing the applied voltages, thereby increasing the internal electric field. The resulting breakdown voltage is inversely proportional to the doping density if one ignores the weak doping dependence of the electric field at breakdown. Breakdown voltage and depletion layer width at breakdown versus doping density of an abrupt one-sided p-n diode. ece-www.colorado.edu /~bart/book/book/chapter4/ch4_5.htm   (699 words)

Semiconductor device with a protective diode having a high breakdown voltage - Patent 6570237 Consequently, the breakdown voltage of the parasitic diode constructed by the well and the substrate is not lower than the rated voltage of the semiconductor device and not higher than the breakdown voltage of the high voltage semiconductor device. In a conventional semiconductor device, the breakdown voltage of the periphery of a high voltage NPN transistor, which is the breakdown voltage of the parasitic diode constructed by a well and a substrate, is higher than the breakdown voltage of the NPN transistor. Consequently, the breakdown voltage of the parasitic diode constructed by the well and the substrate is not lower than the rated voltage and not higher than the breakdown voltage of the high voltage semiconductor device. www.freepatentsonline.com /6570237.html   (2909 words)

Breakdown voltage - Wikipedia, the free encyclopedia Is a parameter of an insulator that defines the maximum voltage difference that can be applied across the material before the insulator collapses and conducts. Two different breakdown voltage measurements of a material are the AC and impulse breakdown voltages. The AC voltage is the line frequency of the mains (either 50 or 60 Hz depending on where you live). en.wikipedia.org /wiki/Breakdown_voltage   (282 words)

CE Magazine: Mr. Static It is often assumed that an electrical breakdown, be it in a gas, liquid, or solid dielectric, is caused by a high voltage. A breakdown is the result of a substantial increase in the concentration of mobile charge carriers in the medium considered. For electrodes with given dimensions, it is possible to define the critical field strength, the so-called breakdown field strength, and, in the case of two conductors, a corresponding breakdown voltage. www.ce-mag.com /archive/02/01/MrStatic.html   (2320 words)

Nanotechnology at Zyvex The breakdown voltage is the level at which the insulating dielectric begins to allow charge flow. Its counterpart, dielectric strength, indicates the relationship between thickness and breakdown voltage, and is expressed as a ratio of voltage to thickness. Breakdown of a 50 micron by 2 micron polysilicon-filled nitride isolation trench on a silicon-based MEMS device. www.zyvex.com /Products/MEBD_001a.htm   (2273 words)

NTT - TECHNICAL BULLETIN: DIELECTRIC BREAKDOWN VOLTAGE The dielectric breakdown voltage is a measure of an insulating fluids ability to withstand a high electric field stress without breaking down. The dielectric breakdown voltage is not a constant of the material being tested like the dielectric constant but it is a statistical process and as a result repetitive determinations have to be done. A 60 Hz sinusoidal wave voltage is applied at a ramp rate of 3000 V/s until breakdown occurs as indicated by passage of a current through the sample of 2 to 20 mA. www.nttworldwide.com /tech2208.htm   (614 words)

SPECIAL DEVICES The breakdown is at a higher voltage because of the higher resistivity of the material. Once the critical or breakdown voltage has been reached, sufficient energy is gained by the thermally released minority electrons to enable the electrons to rupture covalent bonds as they collide with lattice atoms. Once the breakdown voltage of a Zener diode is reached, the voltage across the diode remains almost constant regardless of the supply voltage. www.tpub.com /neets/book7/26.htm   (1819 words)

Voltage Multipliers, Inc. Diodes Appendix A: Reverse Breakdown Voltage   (Site not responding. Last check: 2007-09-11) The reverse breakdown voltage (BVR) of silicon is determined primarily by three factors: the resistivity of the silicon (avalanche), the depletion region width (punch-through or reach-through) and the surface stress at the junction/passivation (zener) interface. Reverse breakdown occurs when the voltage stress across one of these three areas exceeds the withstanding threshold and triggers a high reverse current across the entire junction area, as shown in Figure 3 below. It should be noted, however, that high voltage zener diodes are less practical because the higher-resistivity silicon and deeper-diffusion depths required to achieve the higher voltage ratings make it difficult to predict the voltage at which breakdown occurs. www.voltagemultipliers.com /html/bvr.html   (322 words)

NTT - TECHNICAL BULLETIN: PARTICLE INFLUENCE For both DC and AC the ratio, of breakdown voltage for clean oil to oil with non-conducting particles is nearly the same. However, with an increase in gap distance between the electrodes, the breakdown stress decreased for the oil with the smallest particles and increased for the larger particles. The relatively greater influence of particles and the lower breakdown strength with direct voltage compared with alternating voltage does suggest that conservative design and care in manufacture may be especially important with such DC apparatus. www.nttworldwide.com /tech2210.htm   (2280 words)

Empfasis - Ask The EMPF Helpline! - Dielectric Testing The voltage was applied between conductor patterns of the individual layers and an electrically isolated pattern of the adjacent layers. The dielectric withstanding voltage test (also called high potential, over potential, voltage breakdown or dielectric strength test) applies a voltage higher than the test subject’s rated voltage for a specific duration between electrically isolated circuits and portions of a PCB, or between its isolated circuits, portions, and ground. Dielectric breakdown is a phenomena that typically must be avoided in circuit design to prevent failures leading to the replacement of the module and possibly further damage to adjacent circuits. www.empf.org /empfasis/july04/help704.htm   (916 words)

Reynolds Industries Inc. - High Voltage Connectors, High Voltage Cable Assemblies, High Voltage Wire, High Voltage ... The glow voltage of a tube is relatively independent of the breakdown voltage and is largely determined by the cathode material, the gas type and gas pressure. Thus the DC breakdown voltage of a gas tube is fixed during manufacture, being a function primarily of the electrode spacing, fill gas type and the fill pressure. As mentioned previously, the breakdown voltage of a gap is determined by the gap spacing, the gas type and the internal pressure. www.reynoldsindustries.com /product/7micacapacitor/transient.asp   (4435 words)

Electrical breakdown - Wikipedia, the free encyclopedia Electrical breakdown is often associated with the failure of solid or liquid insulating materials used inside high voltage transformers or capacitors in the electricity distribution grid. Electrical breakdown occurs within a gas (or mixture of gases, such as air) when the dielectric strength of the gas(es) is exceeded. Partial breakdown of the air occurs as a corona discharge on high voltage conductors at points with the highest electrical stress. en.wikipedia.org /wiki/Electrical_breakdown   (944 words)

Terms A-B The voltage that appears across the terminals of an arrester during passage of discharge current. An air-gap device connected in parallel with a sealed gas-tube device, having a higher breakdown voltage than the gas tube, which provides a secondary means of protection in the event of a venting to atmosphere by the primary gas-tube device. The maximum voltage across the device in or at the breakdown region measured under specified voltage rate of rise and current rate of rise. grouper.ieee.org /groups/spd/html/terms_a-b.html   (1081 words)

Workshop for Low Temperature, High Voltage Problems in Electric Power Engineering Stephan Fink presented an analysis of the voltage distribution in a conventional superconducting cable-in-conduit encased in a structure for the D-shaped toroidal coils for ITER. I would expect the breakdown voltage or field to be increased for flowing nitrogen, because it appears the breakdown is through the gas of the bubble connecting the electrodes in the static nitrogen case. He describes static breakdown as no bubbles present in the LHe, and dynamic breakdown as occurring when bubbles are present in the helium (such as when a low Tc magnet quenches). www.energetics.com /lthvsupercon.html   (2855 words)

Electronics I Experiment on Zener Diodes   (Site not responding. Last check: 2007-09-11) Zener breakdown is one example of "tunneling" phenomena that occurs in solid state devices as electrons and holes actually go "through" rather than "over" a potential energy barrier due to quantum mechanical effects associated with the wave characteristics of electrons and the Heisenberg Uncertainty Principle. is the onset or "knee" voltage of the breakdown. The extremely steep slope of the breakdown region means that huge variations in current can be accommodated with negligible variations in voltage; this allows a Zener diode to be used as a voltage regulator. engr.astate.edu /jdg/Electronics/Lab1/07Zener.html   (1285 words)

MOS fuse with programmable tunnel oxide breakdown - Patent 5258947   (Site not responding. Last check: 2007-09-11) It may be recalled that the threshold voltage is the minimum voltage that must be applied to the control gate GC for the memory cell C to become conductive. Besides, a regulator RG with digital control as described enables the use, for the breakdown, of a voltage Vpp with steep front, with a value that is higher than that of the slow-rising edge. A higher breakdown voltage such as this, combined with a steep edge, enables the breakdown of the tunnel oxide to be improved. www.freepatentsonline.com /5258947.html   (5301 words)

W0RPK HAB High Voltage Standard spark-gap breakdown voltage is 75KV/inch at standard temperature and pressure, 25dC and 760mm hg (aka 760 torr). Within the pressure and temperature ranges we operate, breakdown voltage is approximately proportional with pressure and, to a much lesser degree (pun intended), inversely proportional with absolute temperature (dK). Assuming 500V, the breakdown gap at STP is roughly 6.6 mils (thousandths of an inch). showcase.netins.net /web/wallio/ARHAB_Highvoltage.html   (521 words)

Stable Breakdown Obtained in Silicon Carbide Rectifiers In this context, a stable or unstable breakdown-voltage characteristic of a semiconductor rectifier is synonymous with a positive or negative value, respectively, of the temperature coefficient of breakdown voltage. These waveforms show that as the device becomes heated by the breakdown current during the pulse interval, the voltage across the device increases, while the current through the device decreases; this behavior is consistent with a positive temperature coefficient of breakdown voltage and thus with a stable breakdown-voltage characteristic needed for reliability. The Voltage and Current Responses of the Diode are consistent with a positive temperature coefficient of breakdown voltage. www.nasatech.com /Briefs/Aug98/LLEW16551.html   (600 words)

American Micro Semiconductor — Frequently Asked Questions A rapid voltage rise charges the thyristor’s junction capacitance and when the current exceeds the gate trigger current, the thyristor is triggered into conduction. The FET on the other hand is a transconductance device, that is an input voltage results in an output current G=Id/Vg, where Id is the output or drain current and Vg is the input or gate voltage. Pinchoff occurs when the depletion zone, caused by increased reverse gate voltage, extends into the FET channel to the extent that the FET channel resistance reaches some maximum value and the channel current is minimum. www.americanmicrosemi.com /information/faq   (1468 words)

Insulator breakdown voltage - Chapter 12: THE PHYSICS OF CONDUCTORS AND INSULATORS - Volume I - DC After breakdown, the material may or may not behave as an insulator any more, the molecular structure having been altered by the breach. With a high enough applied voltage, electrons can be freed from the atoms of insulating materials, resulting in current through that material. The minimum voltage required to "violate" an insulator by forcing current through it is called the breakdown voltage, or dielectric strength. www.allaboutcircuits.com /vol_1/chpt_12/8.html   (432 words)

Gaseous Breakdown & Paschen's Law The law essentially states that the breakdown characteristics of a gap are a function (generally not linear) of the product of the gas pressure and the gap length, usually written as V= f(pd), where p is the pressure and d is the gap distance. Paschen's Law reflects the Townsend breakdown mechanism in gases, that is, a cascading of secondary electrons emitted by collisions in the gap. Note that the sparking voltage is affected by the electrode material, with cathodes of Barium and Magnesium having higher voltages than Aluminum, for example. home.earthlink.net /~jimlux/hv/paschen.htm   (565 words)

Hipot Testing FAQ - Introduction to Hipot Testing With dielectric breakdown testing you are trying to answer the question "How much voltage can I apply between the wires before the insulation fails?" You increase the voltage until the the current suddenly increases. In dielectric withstand testing you are trying to answer the question "Will this cable withstand a required voltage for a required time?" You apply the voltage for the amount of time and watch the current that flows. Dielectric breakdown testing may be required during the development of assemblies used in critical applications. www.cirris.com /testing/guidelines/hipot_testing.html   (1345 words)

Sphere Gap Breakdown Voltage Tables   (Site not responding. Last check: 2007-09-11) The following two tables give the breakdown voltages for a standard sphere gap of the specified sphere size and spacing. In general, voltages for spheres larger than the largest for which there is a voltage will be the same. That is, 200 cm spheres with a 0.5 cm gap will breakdown at the same voltage as a 15 cm sphere at the same spacing. home.earthlink.net /~jimlux/hv/spherev.htm   (277 words)

(WO/1991/010147) DEVICE FOR AUTOMATICALLY ASCERTAINING CAPACITOR BREAKDOWN VOLTAGE   (Site not responding. Last check: 2007-09-11) Also included in the test apparatus is circuitry (20 and 94) for energizing predetermined ones of the relays in accordance with a predetermined sequence thereby to connect the capacitor associated with each relay to the high voltage source. Control circuitry (20 and 140) is provided for controlling the output of the voltage source to apply a predetermined high voltage signal having a predetermined waveform associated therewith to each capacitor connected to the source by the energization of a relay. The record value of the high voltage defines the breakdown voltage of the capacitor. www.wipo.int /pctdb/en/wo.jsp?WO=1991/10147   (451 words)

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