A diode is a device found in electronic equipment that is used to regulate current. The diode is a a passive device that consumes power. It does not produce any power. Use of the terms "open diode" and "closed diode" refer to the flow of current through the diode. An open diode is one in which an open circuit in a reverse-biased diode has no current flowing through it.
A diode is one of many components of electronic equipment. All components facilitate or control the flow of electrical current. A component like a diode can stand alone or be built into a chip. Each component serves a purpose; for diodes it involves directing the flow of electricity in one direction like an opened valve.
Voltage represents the force of the current flowing through a diode. When a diode is on, current is flowing without voltage. It behaves like a short circuit. When the diode is off, no current flows through, making it an open circuit with negative voltage.
Transforming AC to DC
Use diodes to transform AC, or alternating current, to DC, or direct current. AC is the type of electrical current which is produced by power companies and enters the home through electrical outlets. DC is the power produced by a battery. The diode is able to transform the current due to its ability to restrict flow to one direction. Once AC current becomes DC current it will not reverse flow.
Reverse Biased Diode
A reverse-biased diode has no current flowing through it, thus making it an open circuit. The voltage is greater on the positive side than on the negative side. This is the opposite situation from a forward-based diode, which is a short circuit.