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[ I * (N2+N/2)] |
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Vrip = |
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8*f*c |
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N = number of stages
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f = AC input frequency (Hz)
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c = capacitance per stage (farads)
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I= DC output current (amps)
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Calculate Ripple Voltage Example
Calculate the ripple voltage of a 6 stage multiplier with 1000pF capacitors, 50kHz operating frequency (sine wave), 1mA DC output current, 20kV DC output voltage as follows:
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Vrip = |
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[ 1*10-3 (62+6/2)) ]
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where N = 6, f = 50kHz, c = 1000pf, I = 1mA.
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8 (50,000) (1*10-9)
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Vrip = |
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97.5V |
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An equivalent parallel multiplier would require each capacitor stage to equal the total series capacitance of the AC capacitor bank.
In the above case, the 3 capacitors in the DC bank would equal 1000pF/3 or 333pF. The parallel equivalent would require 333pF capacitors in each stage. However, each successive stage
would require a higher voltage capacitor. |
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