An N-phase by M-stage capacitor-diode voltage multiplier (CDVM) is described. The multiplier is failure tolerant and suitable for medium power applications. Total capacitor weight is significantly less than single-phase multipliers. Excellent correlation between test data and predicted values for output voltage, peak currents, and efficiency demonstrated the accuracy of the generalized equations. The design principles of the multiphase CDVM concept were applied to design, fabricate, and test a breadboard model circuit to operate at a 1.2 kW power level under contract NAS 3-20395 with the NASA Lewis Research Center. Test data from a 1 . 2 kW, five-phase CDVM are included.