Pulse width modulated switching power supply
First Claim
1. In a pulse width modulated switching power supply circuit having an input switching means and a plurality of different output voltages, the improvement in a regulator circuit comprising,voltage reference means connected to one of the output for supplying a precision voltage reference,translation means connected between the voltage reference means and each of the outputs for translating each of the output voltages to ground when the voltages are properly regulated,a differential amplifier connected to the translation means for receiving each of the translated output voltages,an optoisolator connected to the differential amplifier and to the input switching means whereby when the output voltages are properly regulated their input switching means is turned to its lowest duty cycle, but when the absolute value of any output voltage is low the differential amplifier diverts current from the optoisolator which increases the duty cycle of the input switching means.
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Accused Products
Abstract
An improved regulator circuit for a pulse width modulated power supply having an input switch and a plurality of different output voltages. A precision reference voltage is connected to one or more op-amplifiers and/or divider networks, each of which is connected to an output voltage for translating the outputs to ground when the voltages are properly regulated. A differential amplifier is connected to each of the operational amplifiers and divider networks. When the absolute value of any voltages goes low, the corresponding input to the differential amplifier rises and diverts drive current from an optoisolator for increasing the duty cycle of the input switch.
14 Citations
6 Claims
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1. In a pulse width modulated switching power supply circuit having an input switching means and a plurality of different output voltages, the improvement in a regulator circuit comprising,
voltage reference means connected to one of the output for supplying a precision voltage reference, translation means connected between the voltage reference means and each of the outputs for translating each of the output voltages to ground when the voltages are properly regulated, a differential amplifier connected to the translation means for receiving each of the translated output voltages, an optoisolator connected to the differential amplifier and to the input switching means whereby when the output voltages are properly regulated their input switching means is turned to its lowest duty cycle, but when the absolute value of any output voltage is low the differential amplifier diverts current from the optoisolator which increases the duty cycle of the input switching means.
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5. In a Pulse width modulated switching power supply circuit having an input switching means and a plurality of different output voltages, the improvement in a regulator circuit comprising,
voltage reference means connected to one of the outputs for supplying a precision voltage reference, a plurality of operational amplifiers, each having an input and an output, each of the inputs is connected to one of the output voltages for translating each of the output voltages to ground at the amplifier outputs when the voltages are properly regulated, a differential amplifier including a Plurality of transistors, one of which is biased to carry the load, and each of the other transistors are connected to one of the operational amplifier outputs, an optoisolator connected to the differential amplifier and to the input switching means for varying the duty cycle of the input switching means in response to the value of the output voltages.
Specification