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Describing Function Properties of a Magnetic Pulsewidth Modulator

Middlebrook, R. D. (1973) Describing Function Properties of a Magnetic Pulsewidth Modulator. IEEE Transactions on Aerospace and Electronic Systems, AES-9 (3). pp. 386-398. ISSN 0018-9251. doi:10.1109/TAES.1973.309724.

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An analysis is presented for the transfer functions of a particular pulsewidth modulator and power-stage subsystem that has been widely used in practical switching-mode dc regulator systems. The switch and filter are in a "buck" configuration, and the switch is driven by a constant-frequency, variable duty-ratio, push-pull magnetic modulator employing square-loop cores. The two transfer functions considered are that with modulator control signal as input and that with line voltage as input. For ac signals, the corresponding describing functions (DF) are derived. It is shown that current-source drive to the modulator extends the control DF frequency response over that with voltage drive, and that complete cancellation of the effects of line variations can be obtained at dc, but not for ac. Experimental confirmation of the analytical results for the control DF are presented.

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Additional Information:© 1973 IEEE. Presented at the Third IEEE Power Processing and Electronic Specialists Conference, Atlantic City, N.J., May 1972. Manuscript received October 30, 1972.
Issue or Number:3
Record Number:CaltechAUTHORS:20160407-123545120
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:65995
Deposited On:13 Apr 2016 18:39
Last Modified:10 Nov 2021 23:52

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