Villard cascade voltage multiplier.

A voltage multiplier is an electrical circuit that converts AC electrical power from a lower voltage to a higher DC voltage by means of capacitors and diodes combined into a network. Image File history File links Download high resolution version (1640x874, 10 KB) Summary Author: filu. ... Image File history File links Download high resolution version (1640x874, 10 KB) Summary Author: filu. ... An electrical network or electrical circuit is an interconnection of analog electrical elements such as resistors, inductors, capacitors, diodes, switches and transistors. ... International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ... Capacitors: SMD ceramic at top left; SMD tantalum at bottom left; through-hole tantalum at top right; through-hole electrolytic at bottom right. ... Types of diodes. ...

Voltage multipliers can be used to generate bias voltages of a few volts or tens of volts or millions of volts for purposes such as high-energy physics experiments and lightning safety testing.

The most common type of voltage multiplier is the half-wave series multiplier, also called the Villard cascade. Such a circuit is shown opposite.

Assuming that the peak voltage of the AC source is +U_s we can describe the (simplified) working of the cascade as follows:

1. negative peak (−U_s): The C₁ capacitor is charged through diode D₁ to 0V (potential difference between left and right plate of the capacitor is U_s)
2. positive peak (+U_s): the potential of C₁ adds with that of the source, thus charging C₂ to 2U_s through D₂
3. negative peak: potential of C₁ drops to 0V thus allowing C₃ to be charged through D₃ to 2U_s.
4. positive peak: potential of C₁ rises to 2U_s (analogously to step 2), also charging C₄ to 2U_s. The output voltage (the sum of voltages under C₂ and C₄) raises till 4U_s.

In reality more cycles are required for C₄ to reach the full voltage. Adding more segments analogous to C₁-D₁-D₂-C₂, we can increase output voltage by 2U_s. Image File history File links No higher resolution available. ... Josephson junction array chip developed by NIST as a standard volt. ... Potential difference is a quantity in physics related to the amount of energy that would be required to move an object from one place to another against various types of force. ...

Alternative diagrams

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T

The images in this article show the diodes at right angles to the capacitors, stressing that stray capacity between the columns should be minimized.

W

The diodes are arranged diagonally, this stresses that the diodes hold DC-voltage.

Z

Sometimes the capacitors of the two columns are drawn next to each other (no shift), but this makes no sense, as the capacitors are on different potential.

X

Two cascades can be driven by a single center-tapped transformer to get full-wave rectification leading to less ripple.

Stack

A second cascade can be stacked onto the first one driven by a high voltage isolated second secondary winding connected with 180° phase shift to get full wave rectrification.

A single secondary winding of a transformer can drive to cascades of different polarity at the same time. Two of these can in turn be stacked. The goal is to reduce the ripple and the capacity at the same time. To further reduce ripple, an even number of stages is used and the connecting column gets bigger capacitors.

Applications

The high-voltage supplies for cathode ray tubes often use voltage multipliers with the final-stage smoothing capacitor formed by the interior and exterior aquadag coatings on the CRT itself. Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT Electron guns Electron beams Focusing coils Deflection coils Anode connection Mask for separating beams for red, green, and blue part of displayed image Phosphor layer with red, green, and blue zones Close-up of the phosphor... Aquadag is a trade name for a graphite based coating commonly found in Cathode ray tubes. ...

A common type of voltage multiplier used in high-energy physics is the Cockcroft-Walton generator (which was designed by John Douglas Cockcroft and Ernest Thomas Sinton Walton for a particle accelerator, for use in research that won them the Nobel Prize in Physics in 1951). The Cockcroft-Walton (CW) generator, or multiplier, was named after the two men who in 1932 used this circuit design to power their particle accelerator, performing the first artificial nuclear disintegration in history. ... See also: John Cockroft (politician) Sir John Douglas Cockcroft (May 27, 1897 - September 18, 1967) was a British physicist. ... Ernest Thomas Sinton Walton (October 6, 1903 – June 25, 1995) was an Irish physicist, the winner of the 1951 Nobel Prize for Physics along with Sir John Douglas Cockcroft. ... For the DC Comics Superhero also called Atom Smasher, see Albert Rothstein. ... Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ... 1951 (MCMLI) was a common year starting on Monday; see its calendar. ...

See also

• Marx generator (a device that uses spark gaps instead of diodes as the switching elements and can deliver higher peak currents than diodes can)
• Rectifier
• Charge pump

A Marx generator is a type of electrical circuit first described by Erwin Marx in 1924 whose purpose is to generate a high voltage pulse. ... A spark plug. ... AC, half-wave and full wave rectified signals A rectifier is an electrical device, comprising one or more semiconductive devices (such as diodes) or vacuum tubes arranged for converting alternating current to direct current. ... A charge pump is an electronic circuit that uses capacitors as energy storage elements to create either a higher or lower voltage power source. ...

External links

• Basic multiplier circuits
• Cockcroft Walton multipliers
• DC Voltage Booster