Uninterruptible power system

• US 5,532,523 A
• Filed: 05/04/1994
• Issued: 07/02/1996
• Est. Priority Date: 05/04/1994
• Status: Expired due to Fees

• Current Assignee: Sysgration Limited
• Original Assignee: Sysgration Limited
• Inventors: Tang, Yu-Chang
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): FLETCHER, MARLON T
• Application Number:
  US08/237,935
• Time in Patent Office: 790 Days
• Field of Search: 307/64, 307/66, 364/480, 364/492
• US Class Current: 307/64
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

An improved uninterruptible power system including a UPS auto off circuit, a current limit protecting circuit, a power on overload protecting circuit, a simple charging circuit, a relay driver circuit, an external power voltage detecting circuit, a driver circuit, and a synchronizing circuit.

Claims

1. An uninterruptible power supply of the type having an input connected to a primary power supply which in turn is connected to output terminals to which a load is to be connected, said power supply also including means for detecting cut-off of the primary power supply and causing a battery to supply power to an output transformer via a transistor driver circuit, comprising:

means including an auto off circuit for detecting whether the uninterruptible power supply is connected to a load and for supplying a signal to a microprocessor which controls a transistor driver circuit to automatically shut off the power supply when no load is present, said auto off circuit being connected between the output terminals of the power supply by a relay upon detection of power failure at the power supply input;

means including a current limiting circuit for protecting the transistor driver circuit;

means including a power on overload protecting circuit connected between the transistor driver circuit and the microprocessor for detecting whether the load at the output terminals is too large and, if the load is too large, disabling the power supply to protect a fuse at the power supply input from permanent damage due to excessive load;

means including a charging circuit for insuring that the battery is charged within a safe range so as to prolong battery life;

means including a relay driver circuit for driving said relay, said relay driver circuit including means for increasing a relay driving voltage in order to increase the switching speed of the relay, said speed increasing means including a relay driving voltage supply and a capacitor for storing addition relay driving voltage prior to activation of the relay;

means including an external power voltage detecting for detecting whether the external power voltage is too low or too high in order to protect said microprocessor; and

means including a synchronizing circuit for synchronizing, using a phase locked loop, the primary power supply with an output of said transistor driver circuit.