Pulsed DC
Encyclopedia
Pulsed DC or PDC is the form of wave produced from a half-wave rectifier
or a full-wave rectifier
. Full wave rectified ac is more commonly known as Rectified AC. PDC has some characteristics of both alternating current
(AC) and direct current
(DC) waveforms. The voltage
of a DC wave is roughly constant, whereas the voltage of an AC waveform continually varies between positive and negative values. Like an AC wave, the voltage of a PDC wave continually varies, but like a DC wave, the sign of the voltage is constant.
Most modern electronic items function using a DC voltage, so the PDC waveform must usually be smoothed before use. A reservoir capacitor
converts the PDC wave into a DC waveform with some superimposed ripple. When the PDC voltage is initially applied, it charges the capacitor, which acts as a short term storage device to keep the output at an acceptable level while the PDC waveform is at a low voltage. Voltage regulation is often also applied using either linear
or switching regulation.
Pulsed DC may also be generated for purposes other than rectification. It is often used to reduce electrical arcs when generating thin carbon
films, http://www.astex.com/eni-rcsi-TN.html and for increasing yield in semiconductor fabrication
by reducing electrostatic build-up. http://www.freepatentsonline.com/5249094.html It is also generated by the voltage regulators in some automobiles, e.g., the classical air-cooled Volkswagen Beetle.
Rectifier
A rectifier is an electrical device that converts alternating current , which periodically reverses direction, to direct current , which flows in only one direction. The process is known as rectification...
or a full-wave rectifier
Rectifier
A rectifier is an electrical device that converts alternating current , which periodically reverses direction, to direct current , which flows in only one direction. The process is known as rectification...
. Full wave rectified ac is more commonly known as Rectified AC. PDC has some characteristics of both alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
(AC) and direct current
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
(DC) waveforms. The voltage
Voltage
Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
of a DC wave is roughly constant, whereas the voltage of an AC waveform continually varies between positive and negative values. Like an AC wave, the voltage of a PDC wave continually varies, but like a DC wave, the sign of the voltage is constant.
Most modern electronic items function using a DC voltage, so the PDC waveform must usually be smoothed before use. A reservoir capacitor
Reservoir capacitor
A reservoir capacitor is a capacitor that is used to smooth the pulsating DC from an AC rectifier.-Performance with low impedance source:...
converts the PDC wave into a DC waveform with some superimposed ripple. When the PDC voltage is initially applied, it charges the capacitor, which acts as a short term storage device to keep the output at an acceptable level while the PDC waveform is at a low voltage. Voltage regulation is often also applied using either linear
Linear regulator
In electronics, a linear regulator is a voltage regulator based on an active device operating in its "linear region" or passive devices like Zener diodes operated in their breakdown region...
or switching regulation.
Pulsed DC may also be generated for purposes other than rectification. It is often used to reduce electrical arcs when generating thin carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
films, http://www.astex.com/eni-rcsi-TN.html and for increasing yield in semiconductor fabrication
Semiconductor fabrication
Semiconductor device fabrication is the process used to create the integrated circuits that are present in everyday electrical and electronic devices. It is a multiple-step sequence of photolithographic and chemical processing steps during which electronic circuits are gradually created on a wafer...
by reducing electrostatic build-up. http://www.freepatentsonline.com/5249094.html It is also generated by the voltage regulators in some automobiles, e.g., the classical air-cooled Volkswagen Beetle.