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What type of capacitor should be charged slowly after not being used for a period to prevent damage if a sudden surge?
Wiki User
∙ 10y ago
if exact replacement capacitors are not available,you should substitute it with a capacitor that has
Joe Morris
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How is the capacitor able to account for AC Ripples?
Ripple Voltage is voltage variation across the load and it is the AC component. To answer this question, consider a Half Wave rectifier with a smoothing capacitor: This rectifier will consist of a sinusoidal voltage source, an ideal diode, a capacitor in parallel with the load. At t=0, the voltage across capacitor = load voltage When the circuit is switched on, the capacitor is fully charged as the sinusoidal source reaches its peak. However, the sinusoidal nature causes the source voltage to decline after reaching the peak. This means that no current will flow through the diode. But the capacitor is still charged. So this will supply current to the load while it discharges. But during the discharging period (till the sinusoidal picks up again), the load voltage is an exponential function = peak voltage *exp-[(t - t')*resistance of load*capacitance] Now a key point is that the pulsating current is flowing through the diode to recharge the capacitor. Because of this constant charge and discharge of the capacitor in the cycle, the load voltage has AC ripples. At the same time load current is never zero and is directly prop to load voltage. The dc component >> ac component and the ripple voltage is greatly reduced by the capacitance esp a large one. You can minimize these by choosing a large capacitance. This is how a capacitor accounts for AC ripples. You can never actually rid these ripples even if you use a full-wave rectifier! Google search half - wave rectifier graphs on the ripples to understand this!! --- Sona
Why capacitor block direct current?
A capacitor opposes a change in voltage, but it will help to look at both the device and at a circuit up close to see what's going on. Any capacitor is two "plates" separated by a dielectric or insulator. Connect a wire to each plate and you've got the device. In a direct current circuit, the voltage source will cause current flow in only one direction. A common battery is a good example. Let's look further. When a capacitor is connected in a DC circuit and the circuit is energized, the voltage source will want to cause current to flow in only the one direction. In the initial moment when the power is switched on, electrons will flow in the circuit. Electrons will leave the negative terminal of the source and enter the positive terminal. The current flow will travel through the wire, and electrons will "pile up" on one of the plates of the capacitor. As electrons are "piling up" on one plate, their presence there will create an electric field across the dielectric to the other plate. This electric field will cause electrons on that other plate to leave. The capacitor is charging, and the voltage source will, for the first instant of time, think that things are "fine" and current will flow. But as the capacitor charges, current flow drops off, and it eventually stops when the voltage across the plates equals the source voltage. In review, as the DC power is switched on in a circuit with a capacitor in it, current will flow "normally" for the first instant. But as the first electrons arrive on one plate and force them off the other plate, current in the circuit will begin dropping off. The voltage developing across the plates of the capacitor opposes the battery voltage. Eventually the capacitor is charged and all current flow has stopped. There is some math that says something slightly different, but for all practical purposes, the capacitor is considered fully charged in a very short period of time. This will depend on circuit resistance and the ability of the source to deliver current, of course. But that capacitor will, when charged, not "pass" any more current. The voltage across the plates is equal to (an opposing) the source voltage, and no more electrons can get onto the negative plate to force more off the positive plate.
Why is it dangerous to touch terminals of high voltage capacitor even after applied potential difference has been turned off?
A capacitor is used to store charge. It does this by the means of an electrochemical reaction. After the charging circuit is turned off, this charge - if not discharged by any means - is still present in the capacitor. High-Voltage capacitors can amass sufficient current for it to be lethal at said voltage, and they can deliver all of it at the slightest contact.For example, a flasher circuit used in a typical photo camera can deliver lethal voltage, even when it's been charged from a 1.5V battery. The current doesn't need to be high (and is typically very low).I've made this mistake more than once in my life, and I've had screwdrivers welded to the capacitor terminals by their charge. :DIt is worthy of note that some devices and circuits act as capacitors even when they're not designated as such! For example, a Cathode-Ray Tube (the big-ass thing in a tube TV) is a very good high-voltage capacitor itself, and can hold a charge for a long time (even weeks)!
Why a capacitor of higher value is preferable?
It can hold a very large amount of charge and release the same over along period of time. It depends in what circuit you are using it. For power supply decoupling and regulation, bigger is better. If you change the capactior value in a timing or tuned circuit, it will not behave as designed.
Explain why a 24v system that runs off of 4 batteries which includes a 12v feed- that's powered by two of the batteries are getting no charge from the alternator.. the other two are charged well.?
With the batteries in series, the alternator provides the same current, and therefore the same charge to all the batteries. The alternator can take no account of any current being drawn from the 12V take off point. Part of the charge current is being fed to the 12V load and not to the batteries. Therefore, the 12-24V batteries are being fully charged while the 0-12V batteries are being partially charged. Over a period of time, the difference between the charge levels will become more obvious.
Why do capacitor do not discharge in clamping circuits even though their is resistance?
Because the time it takes the capacitor to discharge equals the capacitance multiplied by the resistance which is high enough to keep the capacitor charged for a time longer than the diode-off period. For example at a resistance of 100KOhm and a capacitor of 1 microF, the time constant equals 1s, which is significantly larger than the period of a standard 1KHz input signal.
An uncharged capacitor acts like a short circuit when voltage is first applied to it?
Yes it does. Capacitors and capacitor banks have a high inrush current when first energized. As an example this is the reason that VFD's place a resistor in series with the capacitors for a short period of time when they are first energized to prevent damage to the rectification componente. They call it a precharge circuit. Current leads voltage by 90 deg in a purely capacitive circuit.
Can using a 45 5 uf 370v capacitor in place of 45 5 440v capacitor damage compressor?
yes you can but, the compressor may not run as well and the capacitor may smoke and break if the compressor runs for an extended period of time so, make sure you check it the first couple of time you use the compressor.
How does a capacitor get charged?
a capacitor is used to store charge for longer period of time.in odder to understand that how a capacitor gets charged consider two parallel metal plates.these plates are neutral having equal amount of positive and negative charges.now connect these plates to the opposite terminals of a battery.the electrons present in the plate connected to the positive terminal of a battery will be attracted by the positive terminal leaving the plate positively charged.now these electrons are pushed by the battery to its negative terminal which repels these electrons to the plate connected to it making it negatively charged. now the battery is disconnected.so in this way the plates of a capacitor gets charged.as these plates have opposite charges stored on them force of attraction exist between them enabling a capacitor to store charge for longer periods of time.
What is the name of the component that stores electricity for a short period of time?
capacitor
Electronic device that can hold an electrical charge for a period of time?
A capacitor!
Why the capacitor time period formula is given as t equals RC?
-- The quantity 'RC' has the physical dimensions of Time. -- If the capacitor is charging through a resistor, then 'RC' is the time it takes to charge up to (1 - 1/e) of the voltage it still has to go to become fully-charged. -- If the capacitor is discharging through a resistor, then 'RC' is the time it takes to discharge to 1/e of its present voltage. -- ' e ' is the base of natural logarithms, approximately 2.71828... -- 'RC' is called the 'time constant' of the resistor/capacitor combination.
What are the advantages and disadvantege of capacitors?
Capacitors are very good for storing small quantities of electrical energy, for creating timing circuits based on the time it takes a capacitor to charge, and there are also excellent uses of their characteristic of conducting a varying voltage.
Why do the interior lights stay on when mydoors are shut in my 91 Toyota 4Runner?
The interior lights will remain on for a duration of time after the doors are shut as a safety/courtesy feature. The reason they remain on is the capacitor in the lighting electrical circuitry. The capacitor passes on energy when the circuit is powered, and retains voltage when the circuit is powered down. Once the circuit is powered down, i.e. the vehicle shut off and doors closed, the capacitor still holds that charged voltage and discharges itself over a period of time, usually 30 seconds or so. As it discharges, the electricity moves through the circuit and through the bulbs until the capacitor is completely discharged. Hope this helps!
Can ulcer prevent girls period?
No
Why a capacitor burst if applies full voltage momentarly?
A capacitor is essentially two metal plates with a small opening separating them. If you apply more voltage than the capacitor is rated for, the small openning will not be wide enough to keep the electrons from "jumping across"; current will flow through the capacitor like it is just a piece of wire. This causes the capacitor to heat up significantly. It will eventually burst if enough voltage is left on it for a long enough period of time. If the voltage applied is within the specifications of the capacitor, it may be that it's a polarized capacitor and you're applying voltage backwards to it.
Are period cost a part of inventory cost?
No, A period cost is not the part of inventory cost. Period cost must be charged in the period in whcih it is incurred.
