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If capacitors dont use ac current then how and why are they used in most appliances?
Wiki User
∙ 14y ago
Capacitors resist a change in voltage, proportional to capacitance and current. This is called capacitive reactance. As a result, a capacitor in an AC circuit will create a leading phase angle, current relative to voltage. This, for example, can be used to help start a motor by creating two magnetic fields, one leading the other.
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∙ 14y ago
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Does a capacitor block ac current dc current or both?
No you can't use DC capacitors in Ac because in DC current , the current flows directly while in AC current, the current flows curved zig-zag. Thus Dc equipment can't mingle with AC as they need Direct flow. So DC capacitors can't be used for AC current...................AnswerMost capacitors will operate on either DC or AC. The exception is the polarised-type capacitor, which is designed to operate with a DC or an appropriately-biased supply.Often, a capacitor's rated voltages is specified in terms of DC -for example, '100 V (DC)', so care must be exercised if it is to be used with AC. This is because we always measure AC voltages as root-mean-square (rms) values, not as peak values. For example, '100 V (AC)' actually peaks at 141 V*. So, applying 100 V (AC) to a capacitor rated at 100 V (DC) may cause its dielectric to fail. In this example, the maximum allowable AC voltage must be 70.7 V, which peaks at 100 V.(*To explain: Vrms = 0.707 Vmax )
How do you calculate DC link capacitors?
Its a very difficult subject to which most of my fellow designers estimate the ripple current in the caps and then select capacitors that can handle that current. The idea of voltage droop om most DC links can be forgotten because of other compensators such as a lower BEMF motor. The problem is to get as much life out of the caps as you can and that's to keep them cool as you can. Assume that every amp delivered from the DC like is an amp of ripple current and you should be OK.
What is advantage of ac generation rather than dc generation?
!! In india and most of the other countries user ac current. Hence, all the appliances are ac dependable. So generating ac directly would allow up to directly feed the appliances without any converter circuit.
Why seres capacitors are used in transmission lines?
A poor power factor (due to large reactive loads) in a transmission system will reduce the voltage on local bus bars. Typically, especially for industrial facilities, there will be a large inductive component to the system loads, by installing shunt capacitors in close proximity to these loads the inductive component is effectively cancelled out, allowing the transmission lines to carry greater real power.[Once the capacitors are charged the reactive power demand of the inductive load is fulfilled by the charge/discharge cycle of the capacitors rather than by long-distance transmission of reactive power].
Most commonly used capacitors in electronics circuits are made up of?
pass AC voltages.
The electrical circuit most likely used in everyday appliances is?
AC - Alternating Current
What is the best electric current?
This depends upon the application. For most home appliances and industrial machinery, alternating current is the best electric current. In most computer electronics, alternating current must be converted into direct current.
Does a capacitor block ac current dc current or both?
No you can't use DC capacitors in Ac because in DC current , the current flows directly while in AC current, the current flows curved zig-zag. Thus Dc equipment can't mingle with AC as they need Direct flow. So DC capacitors can't be used for AC current...................AnswerMost capacitors will operate on either DC or AC. The exception is the polarised-type capacitor, which is designed to operate with a DC or an appropriately-biased supply.Often, a capacitor's rated voltages is specified in terms of DC -for example, '100 V (DC)', so care must be exercised if it is to be used with AC. This is because we always measure AC voltages as root-mean-square (rms) values, not as peak values. For example, '100 V (AC)' actually peaks at 141 V*. So, applying 100 V (AC) to a capacitor rated at 100 V (DC) may cause its dielectric to fail. In this example, the maximum allowable AC voltage must be 70.7 V, which peaks at 100 V.(*To explain: Vrms = 0.707 Vmax )
Which type of dielectric is used most often in variable capacitors?
The type of dielectric most often used in variable capacitors is air. Also, trimmer capacitors often use mica.
Why you use capacitors in lines?
Capacitors are connected in series with some lines (series compensated lines) and in parallel. Capacitors in parallel are used to prop up the voltage at that location by injecting reactive power onto the grid. Capacitors in series are used to cancel out some of the inductance of the line, which allows for more power to be transported through the line. Capacitors at load centers are often used for power factor correction, and are connected in parallel (line to ground). To achieve efficiency in a power delivery system it is most efficient to have the current and voltage in phase. Often the load is inductive hence the current lags the voltage (due to motors etc.). Capacitors are switched in and out of the transmission system to counteract this effect.
What capacitors are polarity sensitive?
While most electrolytic capacitors are the ones that have a polarity noted as minus "-" and "+" as opposed to ceramic or film capacitors, it's important to note that even electrolytic capacitors could also be labelled as "np" for non-polarized or "bp" bi-polarized, which means the same thing, that there is no plus or minus and the current can flow in both directions. Today a good quality electrolytic, most of the time, will be another color to depict this such as green for example, whereas in older circuits they could sometimes look identical but just be missing the little "-" indicator. So, you need to pay attention to this little detail on older boards when replacing a capacitor.
How do you calculate DC link capacitors?
Its a very difficult subject to which most of my fellow designers estimate the ripple current in the caps and then select capacitors that can handle that current. The idea of voltage droop om most DC links can be forgotten because of other compensators such as a lower BEMF motor. The problem is to get as much life out of the caps as you can and that's to keep them cool as you can. Assume that every amp delivered from the DC like is an amp of ripple current and you should be OK.
What impact does the California current have on californias climate and why?
the current changes the temperature
Are Household appliances AC or DC?
kettles generally run on alternating current (AC) as do most household appliances. although the heating element can run on either alternating or direct current (ac or dc) as long as the voltage is the same. for example if you were to plug your kettle into your car battery it wouldn't do very much if anything. however if you were to wire ten car batteries in series ( thus creating 120 volts dc) the kettle would heat up as it normally would.
What is the required amount of power supply for household appliances?
Most require a certain voltage and current, as stated on the labels for that product, and not every product is the same.
What are the most important things Nikola Tesla are knowed for?
The invention of the alternant current which the whole world uses to light houses and buildings and to run electricity appliances.
How many type of coupling?
For most parts of electronics is concerned,there are two types of coupling in any alternating current source (AC) circuits: 1)capacitive coupling(Also known as the AC coupling) 2)Inductive Coupling(Also known as the Transformer coupling) Two circuits of different amplification factors and different hybrid parameter values can be merged or coupled by means of a capacitor (capacitive coupling) or an inductor or a transformer (inductive coupling).There are coupling coefficients involved with the transformer.But Capacitor blocks DC and allows AC most of the time.We use ceramic capacitors for this purpose.However never replace the ceramic capacitor with an electrolytic capacitor .Electrolytic capacitors are strictly polar while ceramic capacitors are not.Electrolytic capacitors are used as bypass capacitors.They bypass the current from the resistances that are parallel to them during high frequencies.This is so because the reactance of the capacitor is low at such high frequencies.Also current takes the least resistance path.As reactance gives the AC equivalent of the resistance,current flows into the capacitor while resistance and capacitors are connected end-end and thus the current reaches the other node(its like a diversion or a detour or a shortcut on the road for vehicles-analogously it is the simplest path a current can follow on the conductor
