2023-11-29Archive

Circuit 01 and capacitor

First, let's talk about circuits and capacitors.

The track is road, and charge is car.

If a track is compared to a road, movement of charges can be compared to a traffic flow.

When road is rough, car's speed slows down, but it still moves forward towards its destination. In a circuit, resistance generates heat and dissipates energy (Joule electricity).

A power source (battery) is a device loaded with a potential difference.

A power supply is a device that is loaded with a potential difference E[V] at both ends. For same reason, car uses the elevator to automatically move to a position whose height is t[m].

What is capacitor 02

Next, let's talk about situation when power supply is equipped with a capacitor.

A capacitor is a parking lot.

A capacitor stores an electrical charge. Comparing a circuit to a road, a capacitor is like a parking lot. The positive and negative terminals of circuit must store same amount of charge.

A capacitor can store a charge.

The standard of how much charge a capacitor can store is called capacitance value, and capacitance value is shown in formula (1).

It can be seen from formula (1) that ① electrode area S is increased, ② distance between electrodes is shortened, and ③ capacitance value can be increased by using materials with high dielectric conductivity.

The unit of capacitance is F (Farad) in SI units. When a voltage of 1 V (potential difference) is applied to conductor to store a charge of 1 C (coulomb), capacitance value is 1 F.

Condenser operation 03

The charge stored in capacitor is transferred to load current when switch S1 is off and switch S2 is on.

Depending on condition of capacitor, a stable lamp will light up when supply voltage is unstable.

Capacitors block DC current and allow only AC current to pass through.

Capacitors cannot pass through direct current. If they are repeatedly charged and discharged, charging current and discharge current will be repeated in capacitor.

This phenomenon can be observed by appearance of capacitor to see if current flows through capacitor.

Because of these characteristics, many capacitors are used in circuit.

It is necessary to choose right product for your purpose