# on video Capacitor types

__Charge of a capacitor__

__The switch K i is closed and the switch K2 open. When K is closed, the ammeter shows a high intensity which decreases rapidly and the voltmeter indicates zero when switch K is closed, and the voltage UC then increases rapidly.__

__After a certain time, the intensity I is zero and the voltage UC is maximum, that means UC=UA. The capacitor is said to have charged.__

__At the start of its charge, a capacitor behaves like a zero resistance (short-circuit). We therefore have: UC0 and I0=UA/R, I0 is maximum.__

__At the end of the charging of a capacitor, the latter behaves like an open circuit If=0 and UCF=UA.__

__A capacitor whose shapes are not connected to any circuit retains its charge and maintains a constant voltage between its terminals. The curves obtained are as follows.__

**Décharge d'un condensateur**

Charging time, discharging time

The charge and discharge time is based on the knowledge of the quantity Ø=R.C called time constant. If R in ohm; C to F; Ø in s.

Theoretically the charge or the discharge of a condenser never ends if one does not cut the circuit. The calculation shows that after a time of 3Ø a capacitor which charges reaches 95% of the limit voltage and that after this same time a capacitor which discharges has only 5% of its initial voltage . These percentages are respectively 99% and 1% after a time of 5Ø. One can consider that at the end of 5Ø a condenser which is charged is completely discharged.

Capacitors differ according to the nature of their dielectric. We thus distinguish:

Paper Capacitors

ceramic capacitors

mica capacitors

plastic film capacitors

glass capacitors

Electrolytic or polarized capacitors

Charge of a capacitor

The switch K i is closed and the switch K2 open. When K is closed, the ammeter shows a high intensity which decreases rapidly and the voltmeter indicates zero when switch K is closed, and the voltage UC then increases rapidly.

After a certain time, the intensity I is zero and the voltage UC is maximum, that means UC=UA. The capacitor is said to have charged.

At the start of its charge, a capacitor behaves like a zero resistance (short-circuit). We therefore have: UC0 and I0=UA/R, I0 is maximum.

At the end of the charging of a capacitor, the latter behaves like an open circuit If=0 and UCF=UA.

A capacitor whose shapes are not connected to any circuit retains its charge and maintains a constant voltage between its terminals. The curves obtained are as follows.

discharge of a capacitor

Once C is fully charged, let's open K1 and close K2. The ammeter deviates in the opposite direction, the capacitor has become an active dipole or a generator whose electrical force decreases over time. At the start of the discharge, the voltage across the capacitor is equal to the supply voltage: UC=UA and UR=-UA.

At the end of the discharge, the voltage UC is zero UC=0 and UR=0

Charging time, discharging time

The charge and discharge time is based on the knowledge of the quantity Ø=R.C called time constant. If R in ohm; C to F; Ø in s.

Theoretically the charge or the discharge of a condenser never ends if one does not cut the circuit. The calculation shows that after a time of 3Ø a capacitor which charges reaches 95% of the limit voltage and that after this same time a capacitor which discharges has only 5% of its initial voltage . These percentages are respectively 99% and 1% after a time of 5Ø. One can consider that at the end of 5Ø a condenser which is charged is completely discharged.

__Charge of a capacitor__

__The switch K i is closed and the switch K2 open. When K is closed, the ammeter shows a high intensity which decreases rapidly and the voltmeter indicates zero when switch K is closed, and the voltage UC then increases rapidly.__

__After a certain time, the intensity I is zero and the voltage UC is maximum, that means UC=UA. The capacitor is said to have charged.__

__At the start of its charge, a capacitor behaves like a zero resistance (short-circuit). We therefore have: UC0 and I0=UA/R, I0 is maximum.__

__At the end of the charging of a capacitor, the latter behaves like an open circuit If=0 and UCF=UA.__

__A capacitor whose shapes are not connected to any circuit retains its charge and maintains a constant voltage between its terminals. The curves obtained are as follows.__

**Décharge d'un condensateur**

Charging time, discharging time

The charge and discharge time is based on the knowledge of the quantity Ø=R.C called time constant. If R in ohm; C to F; Ø in s.

Theoretically the charge or the discharge of a condenser never ends if one does not cut the circuit. The calculation shows that after a time of 3Ø a capacitor which charges reaches 95% of the limit voltage and that after this same time a capacitor which discharges has only 5% of its initial voltage . These percentages are respectively 99% and 1% after a time of 5Ø. One can consider that at the end of 5Ø a condenser which is charged is completely discharged.

Capacitors differ according to the nature of their dielectric. We thus distinguish:

Paper Capacitors

ceramic capacitors

mica capacitors

plastic film capacitors

glass capacitors

Electrolytic or polarized capacitors

Charge of a capacitor

At the end of the charging of a capacitor, the latter behaves like an open circuit If=0 and UCF=UA.

discharge of a capacitor

Once C is fully charged, let's open K1 and close K2. The ammeter deviates in the opposite direction, the capacitor has become an active dipole or a generator whose electrical force decreases over time. At the start of the discharge, the voltage across the capacitor is equal to the supply voltage: UC=UA and UR=-UA.

At the end of the discharge, the voltage UC is zero UC=0 and UR=0

Charging time, discharging time

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