Uninterrupted power supply system

A power supply system for providing uninterrupted AC power, comprising:

• a first input port to which to couple AC input power at a specified RMS voltage level from a primary power source, a second input port to which to couple DC input power at a specified voltage level from a backup power source, and an output port to which to connect a device to be powered;
• fullwave rectifying means for generating a first direct current from the AC input power;
• converting means for generating a second direct current from the DC input power at an RMS voltage level approximately equal to that of the AC input power;
• and
• switching means for coupling a selected one of the first and second direct currents to the output port according to whether the AC input power is stabilized or interrupted, and for periodically reversing the flow of the selected direct current to the output port to thereby generate AC output power;
• wherein the switching means includes waveform analyzing means for comparing the instantaneous voltage level of the AC input power at each of a plurality of phase angles with a corresponding reference value and generating a stabilized-indicating control signal if the instantaneous voltage level is within predetermined limits for a each of a predetermined number of cycles.

A power supply system for providing uninterrupted AC power, comprising:

• a first input port to which to couple AC input power at a specified RMS voltage level from a primary power source, a second input port to which to couple DC input power at a specified voltage level from a backup power source, and an output port to which to connect a device to be powered;
• fullwave rectifying means for generating a first direct current from the AC input power;
• converting means for generating a second direct current from the DC input power at an RMS voltage level approximately equal to that of the AC input power;
• switching means for coupling a selected one of the first and second direct currents to the output port according to whether the AC input power is stabilized or interrupted, and for periodically reversing the flow of the selected direct current to the output port to thereby generate AC output power;
• first control means for controlling the switching means so that reversal of the first direct current flow to the output port occurs at approximately each zero crossing of the AC input power, to thereby cause the AC output power to have a waveform generally simulating the waveform of the AC input power;
• and
• second control means for controlling the switching means so that the reversal of the second direct current flow to the output port is approximately synchronized with each zero crossing of the AC input power before the first input current is again coupled to the output port;
• wherein the second control means includes means for adjusting the switching period slightly so that the reversal of the second direct current flow to the output port becomes synchronized over a plurality of cycles with each zero crossing of the AC input power.

A power supply system for providing uninterrupted AC power, comprising:

• a first input port to which to couple AC input power at a specified RMS voltage level from a primary power source, a second input port to which to couple DC input power at a specified voltage level from a backup power source, and an output port to which to connect a device to be powered;
• fullwave rectifying means for generating a first direct current from teh AC input power;
• converting means for generating a second direct current from the DC input power at an RMS voltage level approximaely equal to that of the AC input power;
• switching means for coupling a selected one of the first and second direct currents to the output port according to whether the AC input power is stabilized or interrupted, and for periodically reversing the flow of the selected direct current to the output port to thereby generate AC output power;
• on-off switch means for use in activating the system;
• a third input port to which to couple a conventional telephone signal;
• and
• first remote turn-on means responsive to a ring signal coupled to the third input port for activating the on-off switch means.

A power supply system, comprising:

• means for generating a first direct current from a separate source of AC input power to be used as a pirmary power source;
• means for generating a second direct current from a separate source of DC input power to be used as a backup power source in the event of an interruption in the primary power source;
• switching means for coupling a selected one of the first and second direct currents to a separate device to be powered and for periodically reversing the flow of the selected direct current to the device to be powered to thereby generate AC output power;
• and
• microprocessor means for monitoring the AC input power and controlling the switching means accordingly so that the first direct current is coupled to the device to be powered if the AC input power is stabilized, the second direct current is coupled to the device to be powered if the AC input power is interrupted, and current flow to the device to be powered is reversed generally in synchronism with the AC input power;
• wherein the microprocessor means includes means for generating a time varying reference signal against which to compare the waveform of the AC input power for use in determining whether the AC input power is stablized or interrupted.

A method of providing uninterrupted power AC power, comprising:

• rectifying separately supplied AC input power of a specified RMS voltage level to generate a first direct current;
• up-converting separately supplied DC input power to generate a second direct current at an RMS voltage level approximately equal to that of the AC input power;
• coupling a selected one of the first and second direct currents to a device to be powered according to whether the AC input power is stabilized or interrupted;
• and
• reversing the flow of direct current to the device periodically to thereby generate AC output power;
• wherein the step of coupling includes:
• generating a reference waveform;
• comparing the waveform of the AC input power to the reference waveform to determine whether the AC input power is interrupted or stabilized;
• and
• coupling the first direct current to the device to be powered if the AC input power is stablized and coupling the second direct current to the device if the AC input power is interrupted.