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Why should you discharge the capacitor before measuring the capacitance?
Wiki User
∙ 14y ago
If you don't it could fry your equipment. A capacitor can hold a charge for anextremely long time even years depending on the physical size and capacitance. It can hold a strong enough charge to kill.
Wiki User
∙ 14y ago
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What is pressure coil capacitance?
The series resistance (swamping resistance and multiplier) in pressure coil circuit has many turns.So in addition to inductance seen before, there are inter-turn capacitance also.If this capacitance effect exceeds the inductance effect, a phase-shift in pressure coil current will cause an error.When pressure coil capacitance roughly equals the inductance, the errors cancel each other.In most cases the inductance is more than the capacitance and thus the shunting capacitor mentioned before will serve the purpose.
How do you short the capacitor?
There is no resistance between cathode and anode when measured with a multimeter. You can also lick the terminals. If charged, it'll taste much like the terminals of a 9v battery, which, interestingly, tastes much like going down on a girl.
How do you calculate kvar of capacitor bank if you know only the kw?
Your question is rather vague. Are you asking how do you determine the reactive power of a capacitor bank necessary to improve the power factor of a load (in which case, is it a single-phase or a three-phase load), or are you asking how to convert a capacitor bank's capacitance into reactive power?If the former, then you need to know the reactive power of the load before power factor-improvement, and the resulting reactive power after power-factor improvement, and the difference between these two will tell you how much reactive power you need to add in the form of capacitors.
Why you use capacitors before and after regulator ICs in a voltage supply circuit?
The capacitor before the IC is filtering the output of the rectifier, so that the minimum voltage dip between diode conduction cycles is greater than the minimum voltage the IC requires. The capacitor after the IC is stabilizing the IC, by preventing it from oscillating, and responding to quick changes in load faster than the IC can.
What causes a capacitor to blow?
Capacitors can fail for a few reasons, and sometimes the do "blow". Capacitors have voltage limitations which, if they are exceeded may cause internal arcing or flashover. Once initiated, arcing can cause sudden heating and if the circuit supports high enough energy the capacitor can be damaged and may actually come apart. For polarized capacitors, reversing the polarity may even result in catastrophic failure at normal voltage levels. Another reason capacitors fail is as a result of high current. If a capacitor is subjected to high frequency currents of sufficient magnitude internal heating can result and once again damage will result. With enough energy it may come apart. One last way capacitors may be damaged is through sudden discharge. Generally high voltage ceramic capacitors may be charged to high energy levels. With a sudden discharge ceramic capacitors can respond with a piezoelectric effect and the ceramic may actually shatter.
I charged a homemade capacitor with a 9v you touched your tongue to the capacitor and you got no charge?
In order to feel 9V on your tongue, you need enough current, for enough time, for your brain to recognize the current.Homemade capacitors tend to be rather low in capacitance. The resistance of your tongue might then discharge the capacitor rather quickly, and you might not notice the voltage before it goes to zero. Try this with a large capacitor, such as a few hundred microfarads and see what happens. Please do not charge the capacitor to more than 9V - you do not want to hurt yourself!
How long will it take to fully charge a capacitor in a series RC ciRCuit with a 6microfarad capacitor 2Kilohm resistor and 141 volt supply?
The time it takes to fully charge a capacitor depends on the capacitance and resistance of the circuit; the voltage is irrelevant. The equation you need is:t = 5RCwhere: t = time in seconds, R= resistance in ohms, and C =capacitance in farads.So you should now be able to calculate the time for yourself, but remember to convert the resistance into ohms and the capacitance into farads before you insert the figures into the equation.
How do you discharge high dc voltage capacitor?
When a capacitor is powered off in an energized circuit, the capacitor still stores a certain amount of electricity. When there are other loads or components in the circuit, they will slowly discharge, or they can be quickly discharged by short-circuiting with small resistors or wires (at low voltage). When the capacitor discharges, the two poles of the capacitor respectively carry a certain amount of charge, and the outside world and the capacitor form a closed loop (generally, the closed loop does not include a power supply). The excess electrons (negative charges) approach the positive electrode of the capacitor to form a current, so that the charges at both ends of the capacitor are neutralized. When the neutralization is completed, the electric field between the two electrodes of the capacitor disappears. However, this is in an ideal situation. The amount of terminal charge is exponentially neutralized towards zero, but not zero. Discharge requirements of capacitors After the capacitor is disconnected from the bus, it must be discharged through a discharge resistor or a special voltage transformer. Discharge should be performed between the lead wires of the capacitor and between the lead wires and the casing. The capacitor can be grounded after the capacitor is discharged. Before working on the capacitor, be sure to conduct a test discharge. This discharge is to place the discharge rod on the terminal of the lead wire of the capacitor for a period of time. Even if both sides of the capacitor device are grounded, in order to prevent residual charge on the capacitor, a test discharge must be performed, and each group of capacitors connected in parallel must be discharged. Special care should be taken when conducting inspection discharge of capacitors removed due to faults. Due to the damaged capacitor, the general grounding device may not function as a ground discharge due to a partial disconnection. If the capacitor device has an interlock device, it should be considered that only after the entire device is grounded, the small door of the capacitor bank protective fence can be opened. We're JYH HSU(JEC) Electronics Ltd (or Dongguan Zhixu Electronic Co., Ltd.), an electronic components manufacturer. You may google "JYH HSU" to find our website.
What is pressure coil capacitance?
The series resistance (swamping resistance and multiplier) in pressure coil circuit has many turns.So in addition to inductance seen before, there are inter-turn capacitance also.If this capacitance effect exceeds the inductance effect, a phase-shift in pressure coil current will cause an error.When pressure coil capacitance roughly equals the inductance, the errors cancel each other.In most cases the inductance is more than the capacitance and thus the shunting capacitor mentioned before will serve the purpose.
Why do you have to charge your capacitor?
well...a capacitor RELEASES charge which if BUILT up. that's why... lets say that you have a bucket...and you want to flood a small area...you need to fill up ( charge) the bucket before you can flood (discharge) ANSWER: It has the possibility to discharge if a path can be found. ITS property is to store potential
How does the capacitance change if the voltage across the capacitor is doubled?
As capacitance is not affected by voltage, nothing will happen! Capacitance is affected only by the area of overlap of the plates, their distance apart, and the permittivity of the dielectric.
What is a capacitance?
capacitanceis the ability of a body to store charge in anelectric field. Capacitance is also a measure of the amount of electric potential energy stored (or separated) for a given electric potential.AnswerA capacitor is a device that will store electrical energy. This energy is stored in its electric field. This is achieved by separating the charge on its plates -contrary to popular belief, it does not store that charge, as the net charge remains the same after charging as it was before charging.
Why current leading in capactor?
In the ac waveform of a capacitor the current waveform leads the voltage waveformcurrent is large to start until capacitor fills with it's voltage charge if that helpsAnswerThe terms 'leading' and 'lagging', used when describing power factor, are defined in terms of whether the load current is leading or lagging the supply voltage.In a capacitive circuit, the load current leads the supply voltage, so the power factor is leading.
Do you get discharge if you have not had your period?
Yes. You get discharge before you get your period.
How do you determine capacitor's condition using multimeter for small capacitance?
You can use a multimeter to check the condition of a capacitor by using its highest range for measuring resistance. That range applies the highest voltage - often 9 volts - to the capacitor.If the capacitor is of a polarized type - such as electrolytic - you must be sure to apply the multimeter's test leads to it the correct way round so as to apply the voltage in the right direction so that the capacitor can charge-up.If the capacitor is shorted internally the multimeter will always show a low resistance.If the capacitor is not shorted internally and is in good condition you will see a low resistance at first but, as it charges-up from the applied voltage, you should see the resistance rise in a steady manner until it registers near to infinity.If the capacitor is failing the resistance will stay fairly low because the charge will not be held. If the capacitor is in good condition the charge should be held for several hours and the capacitor can be discharged (by shorting its wires) and then recharged repeatedly.Warning Never ever try to test a capacitor whilst it is still connected into a circuit because: * it must always be discharged safely before you try to test it because you could receive a bad electrical shock if the capacitor is still holding a charge from being in-circuit. Wear rubber gloves on both hands and short its leads away from your eyes because, if it was holding a high voltage charge, there may be a big spark!* other circuit components may get damaged, especially if they are semiconductors;* other circuit components may prevent the capacitor from being charged-up.
What is a CDI?
CDI stands for Capacitor Discharge Ignition system it is an ignition system and also filters the fuel before it enters the engine which is affective First of all, the CDI does NOT filter the fuel -that's what the fuel filter is for! And more specifically, the CDI or Capacitor Discharge Ignition box is a small electrical device which consists of a small transformer, a charging circuit, a main capacitor, and triggering circuit. How it functions is this, First, the transformer takes the normal 12 volts DC from your system and steps the voltage up to around 400 to 600 volts. Then the current which has been increased, flows through the charging circuit to charge the main capacitor. Inside the charging circuit there is a rectifier which prevents the capacitor from discharging prematurely Once the triggering circuit receives the triggering signal from the stator, the triggering circuit temporarily stops the charging circuit, allowing the capacitor to discharge it's stored energy very rapidly to the ignition coil. Then the ignition coil can do it's job of once again stepping up the capacitor's discharge of around 400 to 600 volts up to around 40 kV at the spark plug! Once the capacitor discharges to the ignition coil, it repeats the process again and again. Lastly, you misused the word "affect" -you were probably meaning "effective"... learn your grammar, son!
How do you short the capacitor?
There is no resistance between cathode and anode when measured with a multimeter. You can also lick the terminals. If charged, it'll taste much like the terminals of a 9v battery, which, interestingly, tastes much like going down on a girl.
