To help compare different orders of magnitude, the following list describes various voltage levels.
| SI prefix | Factor (volt) | Value | Item |
|---|---|---|---|
| Micro- | 10−7 | 500 nV | Change in nerve cell potential caused by opening a single acetylcholine receptor channel [1] |
| 10−6 | 2 μV | Noise in an EEG taken at the scalp [2] | |
| Milli- | 10−5 | 10–100 μV | Peak-to-peak amplitude of an average EEG taken at the scalp [2] [3] |
| 15 μV | Minimum terrestrial digital-TV RF antenna signal (−85 dBm over 75 Ω) [4] [5] | ||
| 56 μV | Minimum terrestrial analog-TV RF antenna signal (35 dB[μV]) [6] [7] [8] | ||
| 10−4 | 500–1000 μV | Miniature endplate potentials, spontaneous fluctuations in neuron potentials [1] | |
| 10−3 | 1–2 mV | Potential created at ambient temperatures from K Type Thermocouple | |
| Centi- | 10−2 | ~10–50 mV | Ripple voltage in the output of a good DC power supply [9] |
| 75 mV | Nerve cell resting potential [10] | ||
| Deci- | 10−1 | 320 mV | Typical voltage reference level in consumer audio electronics (0.316 V rms) [11] |
| ~500 mV | Typical MOSFET threshold voltage for modern processes [12] | ||
| ~700 mV | Forward voltage drop of normal silicon diodes [13] | ||
| 800–1000 mV | Typical positive supply voltage of a low voltage CMOS digital integrated circuit [14] | ||
| 900 mV | Lemon battery cell (made with copper and zinc electrodes) [15] | ||
| N/A | 100 | 0-3 V | Magnitudes of standard reduction potentials in chemistry [16] |
| 1.5 V | Alkaline battery AA, AAA, C or D battery [17] | ||
| 3.3 V | One of the most common low voltage CMOS digital circuit supply voltages. | ||
| 5 V | USB power, used for example to charge a cell phone or a digital camera. [18] Also one of the most common digital circuit supply voltages for both TTL and CMOS technologies. | ||
| 6 V | A common voltage for medium-size electric lanterns. [19] A voltage for older electric systems of automobiles. | ||
| Deca- | 101 | 12 V | Typical car battery [20] |
| Hecto- | 102 | 100–240 V | Domestic wall socket voltage [21] |
| 600 V | Electric eel sends this voltage in an average attack | ||
| 630 V | London Underground railway tracks | ||
| Kilo- | 103 | 2450 V | Electric chair execution in Nebraska [22] |
| 3–10 kV | Electric fence [23] | ||
| 3 kV | Voltage required to generate every 1mm of electric arc | ||
| 3–35 kV | Accelerating voltage for a typical television cathode ray tube [24] | ||
| 4160-34,500 V | Typical voltages in North America for distribution of power from distribution substations to end users [25] | ||
| 104 | 15 kV | Train 15 kV AC railway electrification overhead lines, 16+2⁄3 Hz | |
| 25 kV | European high-speed train overhead power lines [26] | ||
| 33 kV | Maximum voltage allowed in an electricity distribution grid after 1919 in the UK until 1926 [27] (still used for heavy industry and factory overhead cable distribution systems) [28] | ||
| 69–230 kV | Range used in North American power high-voltage transmission substations [25] | ||
| 105 | 345–800 kV | Range used in EHV power transmission systems [29] [30] | |
| 800 kV | Lowest voltage used by ultra-high voltage (UHV) power transmission systems [31] [30] | ||
| Mega- | 106 | 3 MV | Used by the ultra-high voltage electron microscope at Osaka University [32] |
| 107 | 25.5 MV | The largest man-made DC voltage – produced in a Van de Graaff generator at Oak Ridge National Laboratory [33] | |
| 108 | 100 MV | The potential difference between the ends of a typical lightning bolt [34] | |
| Peta- | 1015 | 7 PV | Voltage around a particular energetic highly magnetized rotating neutron star [35] |
| Ronna- | 1027 | 1.04 RV | Planck voltage |
| Submultiples | Multiples | |||||
|---|---|---|---|---|---|---|
| Value | SI symbol | Name | Value | SI symbol | Name | |
| 10−1 V | dV | decivolt | 101 V | daV | decavolt | |
| 10−2 V | cV | centivolt | 102 V | hV | hectovolt | |
| 10−3 V | mV | millivolt | 103 V | kV | kilovolt | |
| 10−6 V | µV | microvolt | 106 V | MV | megavolt | |
| 10−9 V | nV | nanovolt | 109 V | GV | gigavolt | |
| 10−12 V | pV | picovolt | 1012 V | TV | teravolt | |
| 10−15 V | fV | femtovolt | 1015 V | PV | petavolt | |
| 10−18 V | aV | attovolt | 1018 V | EV | exavolt | |
| 10−21 V | zV | zeptovolt | 1021 V | ZV | zettavolt | |
| 10−24 V | yV | yoctovolt | 1024 V | YV | yottavolt | |
| 10−27 V | rV | rontovolt | 1027 V | RV | ronnavolt | |
| 10−30 V | qV | quectovolt | 1030 V | QV | quettavolt | |
The amplitudes of the scalp EEG are markedly reduced and lie between 10 and 100 μV
Most good supplies should offer noise and ripple figures of better than 10 mV rms and for switching supplies figures of 50mV or less should be achievable
-10 dBV Standard voltage reference level for consumer and some pro audio use
about 0.7V for all normal diodes which are made from silicon
A diode is a two-terminal electronic component that conducts current primarily in one direction ; it has low resistance in one direction, and high resistance in the other.
The decibel is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 or root-power ratio of 101⁄20.
The volt is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI). It is named after the Italian physicist Alessandro Volta (1745–1827).
dBm or dBmW (decibel-milliwatts) is a unit of level used to indicate that a power level is expressed in decibels (dB) with reference to one milliwatt (mW). It is used in radio, microwave and fiber-optical communication networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form. dBW is a similar unit, referenced to one watt (1000 mW).
Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in decibels. A ratio higher than 1:1 indicates more signal than noise.
Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or even through a vacuum as in electron or ion beams. The electric current flows in a constant direction, distinguishing it from alternating current (AC). A term formerly used for this type of current was galvanic current.
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The reverse operation is performed by the inverter.
In electromagnetism and electronics, electromotive force is an energy transfer to an electric circuit per unit of electric charge, measured in volts. Devices called electrical transducers provide an emf by converting other forms of energy into electrical energy. Other electrical equipment also produce an emf, such as batteries, which convert chemical energy, and generators, which convert mechanical energy. This energy conversion is achieved by physical forces applying physical work on electric charges. However, electromotive force itself is not a physical force.
The Schottky diode, also known as Schottky barrier diode or hot-carrier diode, is a semiconductor diode formed by the junction of a semiconductor with a metal. It has a low forward voltage drop and a very fast switching action. The cat's-whisker detectors used in the early days of wireless and metal rectifiers used in early power applications can be considered primitive Schottky diodes.
In electronics, negative resistance (NR) is a property of some electrical circuits and devices in which an increase in voltage across the device's terminals results in a decrease in electric current through it.
Space charge is an interpretation of a collection of electric charges in which excess electric charge is treated as a continuum of charge distributed over a region of space rather than distinct point-like charges. This model typically applies when charge carriers have been emitted from some region of a solid—the cloud of emitted carriers can form a space charge region if they are sufficiently spread out, or the charged atoms or molecules left behind in the solid can form a space charge region.
A p–n junction is a boundary or interface between two types of semiconductor materials, p-type and n-type, inside a single crystal of semiconductor. The "p" (positive) side contains an excess of holes, while the "n" (negative) side contains an excess of electrons in the outer shells of the electrically neutral atoms there. This allows electrical current to pass through the junction only in one direction. The p-n junction is created by doping, for example by ion implantation, diffusion of dopants, or by epitaxy. If two separate pieces of material were used, this would introduce a grain boundary between the semiconductors that would severely inhibit its utility by scattering the electrons and holes.
Energy harvesting is the process by which energy is derived from external sources, captured, and stored for small, wireless autonomous devices, like those used in wearable electronics and wireless sensor networks.
A microwave power meter is an instrument which measures the electrical power at microwave frequencies typically in the range 100 MHz to 40 GHz.
A betavoltaic device is a type of nuclear battery which generates electric current from beta particles (electrons) emitted from a radioactive source, using semiconductor junctions. A common source used is the hydrogen isotope tritium. Unlike most nuclear power sources which use nuclear radiation to generate heat which then is used to generate electricity, betavoltaic devices use a non-thermal conversion process, converting the electron-hole pairs produced by the ionization trail of beta particles traversing a semiconductor.
In electromagnetics, the antenna factor is defined as the ratio of the electric field E to the voltage V induced across the terminals of an antenna.
dBc is the power ratio of a signal to a carrier signal, expressed in decibels. For example, phase noise is expressed in dBc/Hz at a given frequency offset from the carrier. dBc can also be used as a measurement of Spurious-Free Dynamic Range (SFDR) between the desired signal and unwanted spurious outputs resulting from the use of signal converters such as a digital-to-analog converter or a frequency mixer.
In electronics, an LED circuit or LED driver is an electrical circuit used to power a light-emitting diode (LED). The circuit must provide sufficient current to light the LED at the required brightness, but must limit the current to prevent damaging the LED. The voltage drop across an LED is approximately constant over a wide range of operating current; therefore, a small increase in applied voltage greatly increases the current. Very simple circuits are used for low-power indicator LEDs. More complex, current source circuits are required when driving high-power LEDs for illumination to achieve correct current regulation.
The initial versions of the USB standard specified connectors that were easy to use and that would have acceptable life spans; revisions of the standard added smaller connectors useful for compact portable devices. Higher-speed development of the USB standard gave rise to another family of connectors to permit additional data paths. All versions of USB specify cable properties; version 3.x cables include additional data paths. The USB standard included power supply to peripheral devices; modern versions of the standard extend the power delivery limits for battery charging and devices requiring up to 100 watts. USB has been selected as the standard charging format for many mobile phones, reducing the proliferation of proprietary chargers.
