Misplaced Pages

#568431

62-421: In waveguide systems, as in the electric circuits, it is often desirable to be able to split the circuit power into two or more fractions. In a waveguide system, an element called a junction is used for power division. In a low frequency electrical network, it is possible to combine circuit elements in series or in parallel , thereby dividing the source power among several circuit components. In microwave circuits,

124-433: A 48-volt electrical system , reducing 70% of the wiring in the vehicle. An automobile battery is an example of a wet cell battery, with six cells. Each cell of a lead storage battery consists of alternate plates made of a lead alloy grid filled with sponge lead plates ( cathode ) or coated with lead dioxide ( anode ). Each cell is filled with a sulfuric acid solution, which is the electrolyte. Initially, cells each had

186-411: A lithium-ion battery as an option; from 2018 onward, all Kia Niro conventional hybrids feature one as well. Heavy vehicles may have two batteries in series for a 24   V system or may have series-parallel groups of batteries supplying 24   V. Batteries are grouped by physical size, type and placement of the terminals, and mounting style. Ampere hours (Ah or A·h) is a unit related to

248-587: A parallel circuit , the voltage is the same for all elements. V = V 1 = V 2 = ⋯ = V n {\displaystyle V=V_{1}=V_{2}=\dots =V_{n}} The current in each individual resistor is found by Ohm's law . Factoring out the voltage gives I = ∑ i = 1 n I i = V ∑ i = 1 n 1 R i . {\displaystyle I=\sum _{i=1}^{n}I_{i}=V\sum _{i=1}^{n}{1 \over R_{i}}.} To find

310-462: A series circuits . Each cell provides 2.1 volts for a total of 12.6 volts at full charge. During discharge, at the negative (lead) terminal a chemical reaction releases electrons to the external circuit, and at the positive (lead oxide) terminal another chemical reaction absorbs electrons from the external circuit. This drives the electrons through the external circuit wire (an electrical conductor ) to produce an electric current ( electricity ). As

372-443: A battery's physical dimensions, such as length, width, and height. These groups are determined by the organization. Excess heat is a main cause of battery failures, as when the electrolyte evaporates due to high temperatures, decreasing the effective surface area of the plates exposed to the electrolyte, and leading to sulfation. Grid corrosion rates increase with temperature. Also low temperatures can lead to battery failure. If

434-835: A coil all turns are in series. Capacitors follow the same law using the reciprocals. The total capacitance of capacitors in series is equal to the reciprocal of the sum of the reciprocals of their individual capacitances: [REDACTED] C = ( ∑ i = 1 n 1 C i ) − 1 = ( 1 C 1 + 1 C 2 + 1 C 3 + ⋯ + 1 C n ) − 1 . {\displaystyle C=\left(\sum _{i=1}^{n}{1 \over C_{i}}\right)^{-1}=\left({1 \over C_{1}}+{1 \over C_{2}}+{1 \over C_{3}}+\dots +{1 \over C_{n}}\right)^{-1}.} Equivalently using elastance (the reciprocal of capacitance),

496-892: A complementary relationship: the expression for a series connection of resistances is the same as for parallel connection of conductances, and vice versa. Inductors follow the same law, in that the total inductance of non-coupled inductors in parallel is equal to the reciprocal of the sum of the reciprocals of their individual inductances: [REDACTED] L = ( ∑ i = 1 n 1 L i ) − 1 = ( 1 L 1 + 1 L 2 + 1 L 3 + ⋯ + 1 L n ) − 1 . {\displaystyle L=\left(\sum _{i=1}^{n}{1 \over L_{i}}\right)^{-1}=\left({1 \over L_{1}}+{1 \over L_{2}}+{1 \over L_{3}}+\dots +{1 \over L_{n}}\right)^{-1}.} If

558-399: A different alloy for the plate elements, reducing the amount of water decomposed on charging. A modern battery may not require additional water over its useful life; some types eliminate the individual filler caps for each cell. A weakness of these batteries is that they are very intolerant of deep discharge, such as when the car battery is completely drained by leaving the lights on. This coats

620-441: A filler cap, through which the electrolyte level could be viewed and which allowed water to be added to the cell. The filler cap had a small vent hole which allowed hydrogen gas generated during charging to escape from the cell. The cells are connected by short heavy straps from the positive plates of one cell to the negative plates of the adjacent cell. A pair of heavy terminals, plated with lead to resist corrosion, are mounted at

682-423: A full discharge can reduce the battery's lifespan. As well as starting the engine, an SLI battery supplies the extra power necessary when the vehicle's electrical requirements exceed the supply from the charging system. It is also a stabilizer, evening out potentially damaging voltage spikes . While the engine is running most of the power is provided by the alternator, which includes a voltage regulator to keep

SECTION 10

#1732788113569

744-599: A lead–acid battery ceases to hold a charge, it is deemed a used lead-acid battery (ULAB), which is classified as hazardous waste under the Basel Convention . The 12-volt car battery is the most recycled product in the world, according to the United States Environmental Protection Agency . In the U.S. alone, about 100 million auto batteries a year are replaced, and 99 percent of them are turned in for recycling. However,

806-421: A permeable material. This allows the electrolyte and ions to pass through but keeps the sludge build up from bridging the plates. The sludge largely consists of lead sulfate, which is produced at both electrodes. Battery recycling of automotive batteries reduces the need for resources required for the manufacture of new batteries, diverts toxic lead from landfills, and prevents the risk of improper disposal. Once

868-562: A poorly ventilated setting, combined with an ignition source. Explosions during engine start-up are typically associated with corroded or dirty battery posts. A 1993 study by the US National Highway Traffic Safety Administration said that 31% of vehicle battery explosion injuries occurred while charging the battery. The next-most common scenarios were while working on cable connections, while jump-starting, typically by failing to connect to

930-407: A series circuit, the voltage is the sum of the voltage drops of the individual components (resistance units). V = ∑ i = 1 n V i = I ∑ i = 1 n R i {\displaystyle V=\sum _{i=1}^{n}V_{i}=I\sum _{i=1}^{n}R_{i}} The total resistance of two or more resistors connected in series

992-416: A series or parallel topology . Whether a two-terminal "object" is an electrical component (e.g. a resistor ) or an electrical network (e.g. resistors in series) is a matter of perspective. This article will use "component" to refer to a two-terminal "object" that participates in the series/parallel networks. Components connected in series are connected along a single "electrical path", and each component has

1054-728: A series. Electrical conductance presents a reciprocal quantity to resistance. Total conductance of a series circuits of pure resistances, therefore, can be calculated from the following expression: G = ( ∑ i = 1 n 1 G i ) − 1 = ( 1 G 1 + 1 G 2 + 1 G 3 + ⋯ + 1 G n ) − 1 . {\displaystyle G=\left(\sum _{i=1}^{n}{1 \over G_{i}}\right)^{-1}=\left({1 \over G_{1}}+{1 \over G_{2}}+{1 \over G_{3}}+\dots +{1 \over G_{n}}\right)^{-1}.} For

1116-746: A special case of two conductances in series, the total conductance is equal to: G = G 1 G 2 G 1 + G 2 . {\displaystyle G={\frac {G_{1}G_{2}}{G_{1}+G_{2}}}.} Inductors follow the same law, in that the total inductance of non-coupled inductors in series is equal to the sum of their individual inductances: [REDACTED] L = ∑ i = 1 n L i = L 1 + L 2 + L 3 ⋯ + L n . {\displaystyle L=\sum _{i=1}^{n}L_{i}=L_{1}+L_{2}+L_{3}\cdots +L_{n}.} However, in some situations, it

1178-490: A voltage of at least 10.5 volts. The relationship between the Ah capacity and the discharge rate is not linear; as the discharge rate is increased, the capacity decreases. A battery with a 100 Ah rating generally will not be able to maintain a voltage above 10.5 volts for 10 hours while being discharged at constant rate of 10 amps. Capacity also decreases with temperature. Battery Council International (BCI) group size specifies

1240-407: A waveguide with three independent ports is called a TEE junction. The output of E-Plane Tee is 180° out of phase where the output of H-plane Tee is in phase. For a linearly-polarized antenna, this is the plane containing the electric field vector (sometimes called the E aperture) and the direction of maximum radiation. The electric field or "E" plane determines the polarization or orientation of

1302-587: Is multiple , such as multiple connections for arc lamps . Since electrical conductance G {\displaystyle G} is reciprocal to resistance, the expression for total conductance of a parallel circuit of resistors is simply: G = ∑ i = 1 n G i = G 1 + G 2 + G 3 ⋯ + G n . {\displaystyle G=\sum _{i=1}^{n}G_{i}=G_{1}+G_{2}+G_{3}\cdots +G_{n}.} The relations for total conductance and resistance stand in

SECTION 20

#1732788113569

1364-454: Is best handled by matrix methods and summing the terms of the inverse of the L {\displaystyle L} matrix (3×3 in this case). The pertinent equations are of the form: v i = ∑ j L i , j d i j d t {\displaystyle v_{i}=\sum _{j}L_{i,j}{\frac {di_{j}}{dt}}} The total capacitance of capacitors in parallel

1426-414: Is difficult to prevent adjacent inductors from influencing each other as the magnetic field of one device couples with the windings of its neighbors. This influence is defined by the mutual inductance M. For example, if two inductors are in series, there are two possible equivalent inductances depending on how the magnetic fields of both inductors influence each other. When there are more than two inductors,

1488-404: Is equal to the sum of their individual capacitances: Automotive battery An automotive battery , or car battery , is a rechargeable battery that is used to start a motor vehicle . Its main purpose is to provide an electric current to the electric-powered starting motor , which in turn starts the chemically-powered internal combustion engine that actually propels the vehicle. Once

1550-440: Is equal to the sum of their individual resistances: [REDACTED] R = ∑ i = 1 n R i = R 1 + R 2 + R 3 ⋯ + R n . {\displaystyle R=\sum _{i=1}^{n}R_{i}=R_{1}+R_{2}+R_{3}\cdots +R_{n}.} Here, the subscript s in R s denotes "series", and R s denotes resistance in

1612-420: Is the same, and the voltage across the circuit is the sum of the individual voltage drops across each component. In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents flowing through each component. Consider a very simple circuit consisting of four light bulbs and a 12-volt automotive battery . If a wire joins the battery to one bulb, to

1674-579: Is when the electrodes become coated with a hard layer of lead sulfate, which weakens the battery. Sulfation can happen when battery is not fully charged and remains discharged. Sulfated batteries should be charged slowly to prevent damage. SLI batteries (starting, lighting, and ignition) are not designed for deep discharge, and their life is reduced when subjected to this. Starting batteries have plates designed for increased surface area and thus high instant current capability, whereas marine (hybrid) and deep cycle types will have thicker plates and more room at

1736-600: The current in a component with resistance R i {\displaystyle R_{i}} , use Ohm's law again: I i = V R i . {\displaystyle I_{i}={\frac {V}{R_{i}}}\,.} The components divide the current according to their reciprocal resistances, so, in the case of two resistors, I 1 I 2 = R 2 R 1 . {\displaystyle {\frac {I_{1}}{I_{2}}}={\frac {R_{2}}{R_{1}}}.} An old term for devices connected in parallel

1798-497: The 1990s a 42V electrical system standard was proposed. It was intended to allow more powerful electrically driven accessories, and lighter automobile wiring harnesses. However, the availability of higher-efficiency motors, new wiring techniques, and digital controls, and a focus on hybrid vehicle systems that use high-voltage starter/generators have largely eliminated the push for switching the main automotive voltages. In 2023 Tesla started deliveries of their Cybertruck that uses

1860-471: The 24-volt system. If two or more components are connected in parallel, they have the same difference of potential (voltage) across their ends. The potential differences across the components are the same in magnitude, and they also have identical polarities. The same voltage is applied to all circuit components connected in parallel. The total current is the sum of the currents through the individual components, in accordance with Kirchhoff's current law . In

1922-523: The auxiliary battery with an alternator—instead, they use a DC-to-DC converter to step down the high voltage to the required float-charge voltage (typically around 14 V). Further, an electric vehicle does not have a starter motor, thus needs only a limited amount of power and energy from its auxiliary battery. As such, Tesla introduced in 2021 a lithium-ion auxiliary battery storing only 99  Wh of energy. Early cars did not have batteries, as their electrical systems were limited. Electric power for

E-plane and H-plane - Misplaced Pages Continue

1984-430: The battery discharges , the acid of the electrolyte reacts with the materials of the plates, changing their surface to lead sulfate . When the battery is recharged , the chemical reaction is reversed: the lead sulfate reforms into lead dioxide. With the plates restored to their original condition, the process may be repeated. Some vehicles use other starter batteries. For weight savings, the 2010 Porsche 911 GT3 RS has

2046-432: The battery is discharged to the point where it can't start the engine, the engine can be jump started via an external source of power. Once running, the engine can recharge the battery, if the alternator and charging system are undamaged. Corrosion at the battery terminals can prevent a car from starting due to electrical resistance , which can be prevented by the proper application of dielectric grease . Sulfation

2108-444: The bottom of the plates for spent plate material to gather before shorting the cell. Car batteries using lead-antimony plates require regular topping-up with pure water to replace water lost due to electrolysis and evaporation. By changing the alloying element to calcium, more recent designs have reduced the rate of water loss. Modern car batteries have reduced maintenance requirements, and may not provide caps for addition of water to

2170-511: The cells. Such batteries include extra electrolyte above the plates to allow for losses during the battery life. Some battery manufacturers include a built-in hydrometer to show the state of charge of the battery. The primary wear-out mechanism is the shedding of active material from the battery plates, which accumulates at the bottom of the cells and which may eventually short-circuit the plates. This can be substantially reduced by enclosing one set of plates in plastic separator bags, made from

2232-600: The coils are tightly coupled there can be near short circuit conditions and high circulating currents for both positive and negative values of M , which can cause problems. More than three inductors become more complex and the mutual inductance of each inductor on each other inductor and their influence on each other must be considered. For three coils, there are three mutual inductances M 12 {\displaystyle M_{12}} , M 13 {\displaystyle M_{13}} and M 23 {\displaystyle M_{23}} . This

2294-682: The dead battery before the charging source and failing to connect to the vehicle chassis rather than directly to the grounded battery post, and while checking fluid levels. Close to two-thirds of those injured suffered chemical burns, and nearly three-fourths suffered eye injuries, among other possible injuries. Electric vehicles (EVs) are powered by a high-voltage electric vehicle battery , but they usually have an automotive battery as well, so that they can use standard automotive accessories which are designed to run on 12 V. They are often referred to as auxiliary batteries. Unlike conventional, internal combustion engined vehicles, EVs don't charge

2356-554: The direction of maximum radiation. The magnetizing field or "H" plane lies at a right angle to the "E" plane. For a vertically polarized antenna, the H-plane usually coincides with the horizontal/ azimuth plane. For a horizontally polarized antenna, the H-plane usually coincides with the vertical/elevation plane. Co-polarization (co-pol) and cross-polarization (cross-pol) are defined for the radiating E and H planes. These directions are defined in spherical coordinates corresponding to

2418-497: The energy storage capacity of the battery. This rating is required by law in Europe. The ampere hour rating is generally defined as the product of (the current a battery can provide for 20 hours at a constant rate, at 80 degrees F (26.6 °C), while the voltage drops to a cut-off of 10.5 volts) times 20 hours. In theory, at 80 degrees F, a 100 Ah battery should be able to continuously provide 5 amps for 20 hours while maintaining

2480-514: The engine is running, power for the car's electrical systems is still supplied by the battery, with the alternator charging the battery as demands increase or decrease. Typically, starting uses less than three percent of the battery capacity. For this reason, automotive batteries are designed to deliver maximum current for a short period of time. They are sometimes referred to as "SLI batteries" for this reason, for starting, lighting and ignition. SLI batteries are not designed for deep discharging, and

2542-425: The ignition was provided by a magneto , the engine was started with a crank , headlights were gas-powered and a bell or bulb-horn was used instead of an electric horn. Car batteries became widely used around 1920 as cars became equipped with electric starter motors . The first starting and charging systems were designed to be 6-volt and positive- ground systems, with the vehicle's chassis directly connected to

E-plane and H-plane - Misplaced Pages Continue

2604-712: The inductors are situated in each other's magnetic fields, this approach is invalid due to mutual inductance. If the mutual inductance between two coils in parallel is M , the equivalent inductor is: L = L 1 L 2 − M 2 L 1 + L 2 − 2 M {\displaystyle L={\frac {L_{1}L_{2}-M^{2}}{L_{1}+L_{2}-2M}}} If L 1 = L 2 {\displaystyle L_{1}=L_{2}} L = L + M 2 {\displaystyle L={\frac {L+M}{2}}} The sign of M {\displaystyle M} depends on how

2666-464: The last one will still function. Series circuits are sometimes referred to as current-coupled. The current in a series circuit goes through every component in the circuit. Therefore, all of the components in a series connection carry the same current. A series circuit has only one path through which its current can flow. Opening or breaking a series circuit at any point causes the entire circuit to "open" or stop operating. For example, if even one of

2728-423: The last two groups can be combined. The first three terms represent the sum of the self-inductances of the various coils. The formula is easily extended to any number of series coils with mutual coupling. The method can be used to find the self-inductance of large coils of wire of any cross-sectional shape by computing the sum of the mutual inductance of each turn of wire in the coil with every other turn since in such

2790-602: The lead plate electrodes with lead sulfate deposits and can reduce the battery's lifespan by a third or more. VRLA batteries, also known as absorbed glass mat (AGM) batteries are more tolerant of deep discharge but are more expensive. VRLA batteries do not permit addition of water to the cell. The cells each have an automatic pressure release valve, to protect the case from rupture on severe overcharge or internal failure. A VRLA battery cannot spill its electrolyte which makes it particularly useful in vehicles such as motorcycles. Batteries are typically made of six galvanic cells in

2852-454: The light bulbs are connected in parallel, the currents through the light bulbs combine to form the current in the battery, while the voltage drop is 12 volts across each bulb and they all glow. In a series circuit, every device must function for the circuit to be complete. If one bulb burns out in a series circuit, the entire circuit is broken. In parallel circuits, each light bulb has its own circuit, so all but one light could be burned out, and

2914-402: The light bulbs in an older-style string of Christmas tree lights burns out or is removed, the entire string becomes inoperable until the faulty bulb is replaced. I = I 1 = I 2 = ⋯ = I n {\displaystyle I=I_{1}=I_{2}=\cdots =I_{n}} In a series circuit, the current is the same for all of the elements. In

2976-413: The magnetic fields influence each other. For two equal tightly coupled coils the total inductance is close to that of every single coil. If the polarity of one coil is reversed so that M is negative, then the parallel inductance is nearly zero or the combination is almost non-inductive. It is assumed in the "tightly coupled" case M is very nearly equal to L . However, if the inductances are not equal and

3038-544: The mid-1950s. The changeover from 6 to 12 V happened when bigger engines with higher compression ratios required more electrical power to start. Smaller cars, which required less power to start stayed with 6 V longer, for example the Volkswagen Beetle in the mid-1960s and the Citroën 2CV in 1970. The AGM sealed battery (for automobiles), which did not require refilling, was invented in 1971. In

3100-830: The mutual inductance between each of them and the way the coils influence each other complicates the calculation. For a larger number of coils the total combined inductance is given by the sum of all mutual inductances between the various coils including the mutual inductance of each given coil with itself, which is termed self-inductance or simply inductance. For three coils, there are six mutual inductances M 12 {\displaystyle M_{12}} , M 13 {\displaystyle M_{13}} , M 23 {\displaystyle M_{23}} and M 21 {\displaystyle M_{21}} , M 31 {\displaystyle M_{31}} and M 32 {\displaystyle M_{32}} . There are also

3162-423: The next bulb, to the next bulb, to the next bulb, then back to the battery in one continuous loop, the bulbs are said to be in series. If each bulb is wired to the battery in a separate loop, the bulbs are said to be in parallel. If the four light bulbs are connected in series, the same current flows through all of them and the voltage drop is 3 volts across each bulb, which may not be sufficient to make them glow. If

SECTION 50

#1732788113569

3224-411: The output between 13.5 and 14.5 V. Modern SLI batteries are lead-acid type, using six series-connected cells to provide a nominal 12-volt system (in most passenger vehicles and light trucks), or twelve cells for a 24-volt system in heavy trucks or earth-moving equipment, for example. Gas explosions can occur at the negative electrode where hydrogen gas can build up due to blocked battery vents or

3286-450: The positive battery terminal. Today, almost all road vehicles have a negative ground system. The negative battery terminal is connected to the car's chassis . The Hudson Motor Car Company was the first to use a standardized battery in 1918 when they started using Battery Council International batteries. BCI is the organization that sets the dimensional standards for batteries. Cars used 6 V electrical systems and batteries until

3348-527: The radio wave. For a vertically polarized antenna, the E-plane usually coincides with the vertical/elevation plane. For a horizontally polarized antenna, the E-Plane usually coincides with the horizontal/azimuth plane. E- plane and H-plane should be 90 degrees apart. In the case of the same linearly polarized antenna, this is the plane containing the magnetic field vector (sometimes called the H aperture) and

3410-400: The role of voltage and current . A circuit composed solely of components connected in series is known as a series circuit ; likewise, one connected completely in parallel is known as a parallel circuit . Many circuits can be analyzed as a combination of series and parallel circuits, along with other configurations . In a series circuit, the current that flows through each of the components

3472-498: The same electric current through it, equal to the current through the network. The voltage across the network is equal to the sum of the voltages across each component. Components connected in parallel are connected along multiple paths, and each component has the same voltage across it, equal to the voltage across the network. The current through the network is equal to the sum of the currents through each component. The two preceding statements are equivalent, except for exchanging

3534-629: The spherical wavefronts of the propagating wave. By convention, the co-pol direction is the direction of the E field while the cross-pol direction is the direction of the H field. Receive power for a co-pol oriented antenna is maximum while receive power is minimum for cross-pol orientation. This article related to telecommunications is a stub . You can help Misplaced Pages by expanding it . Series and parallel circuits Two-terminal components and electrical networks can be connected in series or parallel . The resulting electrical network will have two terminals, and itself can participate in

3596-842: The three self-inductances of the three coils: M 11 {\displaystyle M_{11}} , M 22 {\displaystyle M_{22}} and M 33 {\displaystyle M_{33}} . Therefore L = ( M 11 + M 22 + M 33 ) + ( M 12 + M 13 + M 23 ) + ( M 21 + M 31 + M 32 ) {\displaystyle L=\left(M_{11}+M_{22}+M_{33}\right)+\left(M_{12}+M_{13}+M_{23}\right)+\left(M_{21}+M_{31}+M_{32}\right)} By reciprocity, M i j {\displaystyle M_{ij}} = M j i {\displaystyle M_{ji}} so that

3658-451: The top, sometimes the side, of the battery. Early auto batteries used hard rubber cases and wooden plate separators. Modern units use plastic cases and woven sheets to prevent the plates of a cell from touching and short-circuiting. In the past, auto batteries required regular inspection and maintenance to replace water that was decomposed during the operation of the battery. "Low-maintenance" (sometimes called "zero-maintenance") batteries use

3720-840: The total resistance of all components, add the reciprocals of the resistances R i {\displaystyle R_{i}} of each component and take the reciprocal of the sum. Total resistance will always be less than the value of the smallest resistance: [REDACTED] R = ( ∑ i = 1 n 1 R i ) − 1 = ( 1 R 1 + 1 R 2 + 1 R 3 + ⋯ + 1 R n ) − 1 {\displaystyle R=\left(\sum _{i=1}^{n}{1 \over R_{i}}\right)^{-1}=\left({1 \over R_{1}}+{1 \over R_{2}}+{1 \over R_{3}}+\dots +{1 \over R_{n}}\right)^{-1}} For only two resistances,

3782-527: The total series elastance equals the sum of each capacitor's elastance. Two or more switches in series form a logical AND ; the circuit only carries current if all switches are closed. See AND gate . A battery is a collection of electrochemical cells . If the cells are connected in series, the voltage of the battery will be the sum of the cell voltages. For example, a 12 volt car battery contains six 2-volt cells connected in series. Some vehicles, such as trucks, have two 12 volt batteries in series to feed

SECTION 60

#1732788113569

3844-616: The unreciprocated expression is reasonably simple: R = R 1 R 2 R 1 + R 2 . {\displaystyle R={\frac {R_{1}R_{2}}{R_{1}+R_{2}}}.} This sometimes goes by the mnemonic product over sum . For N equal resistances in parallel, the reciprocal sum expression simplifies to: 1 R = N 1 R . {\displaystyle {\frac {1}{R}}=N{\frac {1}{R}}.} and therefore to: R = R N . {\displaystyle R={\frac {R}{N}}.} To find

#568431