Experiment 4 - The Charging Current II

You need to extend the circuit from the last experiment in order to be able to discharge the capacitor again.

Consider the circuit shown. You recognize the circuit from the last experiment, which has been extended by a second push button switch, a LED and a resistor.

• If you press the pushbutton switch S1, the capacitor is charged. This is indicated by LED 1, that shows the charging current.
• If you press the pushbutton switch S2, the capacitor discharges. This is indicated by LED 2, which consumes the energy of the capacitor.

Only when the capacitor is discharged, it can be recharged again while observing the charge current. This can be repeated as often as you like...

Circuit with electrolytic capacitor. (Enlarge)

Circuit diagram with electrolytic capacitor.

Certainly you have realized that the capacitor can not replace a battery. The LED lights up too briefly to be of any practical use.

In the next experiment, it is all about how much energy a capacitor can store and what the unit Farad stands for.