CATV amplifier power supply redundancy

A method for providing automatic redundancy to at least two power supplies configured in parallel, comprising:

• comparing a load voltage coupled to each power supply configured in parallel to a reference voltage and producing an error voltages for each power supply;
• amplifying each error voltage to produce one amplified error voltage having a higher value than all other amplified error voltages;
• switching to a power supply with the highest value amplified error voltage;
• and
• limiting a peak current through a switch coupled to each power supply by a pulse width modulator that adjusts a duty cycle of the switch.

A communications system, comprising:

• a transmission system for providing a signal from a source to a subscriber;
• an amplifier system coupled to the transmission system for amplifying the signal, the amplifier system further comprising:
• an error amplifier circuit for comparing a load voltage and a reference voltage and producing an amplified error voltage for each of the paralleled power supplies;
• a diode coupled to each amplified error voltage wherein the diode receiving the higher error voltage turns on;
• and
• a Pulse Width Modulator (PWM) which limits a peak current through a switch coupled to each of the power supplies by adjusting a duty cycle of the switch whereby the power supply with the higher error voltage automatically becomes a master power supply wherein any remaining power supplies become slave power supplies.

A system for pre-selecting a master power supply, comprising:

• a comparator for comparing a load voltage coupled to the power supplies to a reference voltage resulting in an error voltage associated with each power supply;
• amplifiers for amplifying each error voltage;
• a ground connection for grounding all but one error voltage;
• a diode for allowing the power supply with the ungrounded voltage to remain on and function as a master power supply;
• and
• a modulator for limiting a peak current through a switch coupled to each power supply by adjusting a duty cycle of the switch.

A method for pre-selecting a master power supply, comprising:

• receiving a load voltage by a plurality of comparators that compares the load voltage to a reference voltage and producing an output error voltage for each comparator;
• amplifying each output error voltage;
• grounding all but one output error voltages leaving one output error voltage ungrounded;
• providing the ungrounded output error voltage to a power supply such that the power supply functions as a master power supply;
• and
• regulating a peak current through a switch coupled to the power supply by adjusting a duty cycle of the switch.