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Transformerless DC-to-DC Converters with Large Conversion Ratios

Middlebrook, R. D. (1984) Transformerless DC-to-DC Converters with Large Conversion Ratios. In: International Telecommunications Energy Conference, 1984. INTELEC '84. IEEE , Piscataway, NJ, pp. 455-460.

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A new switching dc-to-dc converter is introduced in which large voltage step-down ratios can be achieved without a very small duty ratio and without a transformer. The circuit is an extension of the Ćuk converter to incorporate a multistage capacitor divider. A particularly suitable application would be a 50V to 5V converter in which dc isolation is not required. The absence of a transformer and a larger duty ratio permits operation at very high switching frequency, and makes the circuit amenable to partial integration and hybrid construction techniques. An experimental three-stage voltage divider Ćuk converter converts 50V to 5V at 50W with an efficiency of 77% at 500 kHz and 71% at 1 MHz, higher than for a basic Ćuk converter operated at the same conditions.

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Additional Information:© 1984 IEEE. This work was conducted under the Power Electronics Program, supported by grants from the General Telephone Co. and from Emerson Electric Co. A patent application has been filed on the voltage-divider Ćuk converter circuit. All of the experimental work, and the derivation of the small-signal model, for the voltage-divider Ćuk converter was done by Steve Freeland, a graduate student in the Caltech Power Electronics Group. He was supported by a National Science Foundation Fellowship.
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General Telephone CompanyUNSPECIFIED
Emerson Electric CompanyUNSPECIFIED
NSF Graduate Research FellowshipUNSPECIFIED
Record Number:CaltechAUTHORS:20160408-121238318
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:66025
Deposited By: Kristin Buxton
Deposited On:13 Apr 2016 18:29
Last Modified:10 Nov 2021 23:52

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