A cylindrical electrolytic cap will store a much larger charge. Some of the large electrolytic caps can store enough charge to kill a person. Another type, called Tantalum Capacitors, store a larger charge in a smaller package. Active Devices are components that are capable of controlling voltages or currents and can create a switching action in the circuit. An example of an active device is a diode .
Diodes are basically a one-way valve for electrical current.
If the negative side is on the negative end of the circuit, current will flow. If the negative is on the positive side of the circuit no current will flow. By accomplishing this, our attempts of comprehending the basic principles of electronic circuits will be fulfulled. Make sure that you do not hook this circuit to a voltage supply. The endpoints of the circuit in the diagram indicate that there is no voltage supply.