In the field of electronics, pulsed DC stands for pulsed direct current (PDC). This form of electric current possesses attributes of both alternating current (AC) and direct current (DC). The pulsed DC power supply delivers a current of a single polarity with a variable voltage. This rectified wave form is produced using either a half-wave or full-wave rectifier.
While PDC current has similar attributes to both AC and DC currents, it is a completely different entity. In a traditional AC current waveform, the voltage is variable as it rises up and down along the wave. Pulsed DC shares this characteristic with AC current but, unlike AC current, the polarity of the current does not change. Like traditional DC current, pulsed DC maintains a single positive or negative polarity.
Pulsed DC is not useful for many modern DC equipment operations until it has been smoothed using a capacitor. The smoothing process entails charging the capacitor to a specific voltage and then releasing the voltage to the circuit as regular DC current. While pulsed DC is not usable by many motors and electronics without modification, it is used by other equipment and processes.
This type of current can be used for the purposes of magnetron sputtering and plasma generation. When used for magnetron sputtering, the most common application of PDC current is in the production of thin film materials. The plasma generated using PDC is more reliable than that created by regular DC current because it cannot be poisoned by the buildup of argon gases. As a result, PDC magnetron sputtering is considered to be superior to regular DC current in the production of thin film materials.
This application of pulsed DC current has made it very useful to the manufacturing and electronics industry. Thin film materials created using this method are used for a variety of electronic components. The ability to produce these materials more reliably in less time makes the use of PDC current a cost effective measure for this industrial application.
The pulsating current of PDC has also been put to good use in welding equipment. In 2005, Barrett Firearms of Murfreesboro, Tennessee began using pulsed DC tungsten inert gas (TIG) welding equipment. The company reported a 45% increase in overall productivity and energy savings of up to 75% as a result of the upgraded equipment. In addition, this type of welding equipment had a lower operating temperature, which reduced the warping factor and created better welds as a result of using PDC current.