04263644 is referenced by 12 patents and cites 6 patents.

A switched DC-to-DC converter in a power supply is powered by input line current from an external power source and driven by voltage pulses from a variable duty cycle pulse width modulator for converting a DC input voltage to a DC supply voltage of a different value that is applied to a load impedance. A comparator monitors the supply voltage for producing an error voltage that biases the modulator for adjusting the width of the voltage pulses, and thus the duty cycle of the converter, for maintaining the supply voltage relatively constant. An RC circuit integrates the voltage pulses for producing an indication of the average value thereof, which is directly related to the value of line current drawn by the converter. When the average value of voltage pulses exceeds a reference voltage, the value of bias voltage is limited for establishing the maximum width of voltage pulses and duty cycle of the converter, and thereby limit the maximum line current drawn by the power supply.

Title
Current limiter for switched DC-to-DC converter
Application Number
6/39727
Publication Number
4263644
Application Date
May 17, 1979
Publication Date
April 21, 1981
Inventor
Neale A Zellmer
Belmont
CA, US
Agent
Russell A Cannon
Assignee
GTE Automatic Electric Laboratories
IL, US
IPC
H02H 1/122
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