3701937 is referenced by 52 patents and cites 4 patents.

A pulse-width modulated DC to DC converter is enabled to operate into short circuits and limit the current output by having the capability of operating at zero percent duty cycle. The regulation feedback loop utilizes a light-emitting diode and phototransistor optical arrangement to permit isolation between the input and output sides of the converter. The light emitting diode is responsive to voltage monitoring and current monitoring circuitry on the output side of the converter. The converter operates in a crossover mode in which the regulation switches from voltage regulation to current regulation or vice versa as load conditions change.

Title
Pulse-width modulated DC to DC converter with zero percent duty cycle capability
Application Number
05/214,312
Publication Number
3701937
Application Date
December 30, 1971
Publication Date
October 31, 1972
Inventor
Donald Earle Combs
Agent
R J Guenther et al
Assignee
Bell Telephone Laboratories
IPC
H02m 03/32
H02M 03/337
H02M 03/24
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