A reserve power supply for providing backup power to a computer system includes a first battery and a second battery which are switchably interconnected in series or parallel by a switch means. When the batteries are connected in parallel they may be charged by a primary power supply which normally drives the computer system. When the batteries are connected in series they provide power to the computer when the primary power supply fails. This association with the primary power supply and the computer system is effected by a coupling circuit of the reserve power supply. The reserve power supply further includes an indicator circuit which visually and audibly signals when the batteries are providing power to the computer system. The reserve power supply further includes an electrical circuit which connects the voltage from one of the batteries to a second voltage output of the primary power supply and a second voltage input of the computer system. This electrical circuit also converts the voltage from the one battery into a plurality of other voltages for use by the computer system.
An electrical energy system comprising a power supply apparatus having an electrical energy storage device for storing electrical energy, an external load having one or more batteries, the load adapted to receive electrical energy from the electrical energy storage device, and wherein the power supply apparatus comprises control circuitry for monitoring a condition of the power supply apparatus and controlling an operation of the load responsive to the monitored condition.
An automatic back-up circuitry for use with a memory circuit or the like including a switch transistor adapted to turn on in response to the application of an operative current and conduct it to the memory circuit, said transistor being also adapted to turn off when the application of the main operative current to said transistor is release, whereupon the back-up voltage is applied to the path between the transistor and the memory circuit.
For use in a system comprising a plurality of devices that are connected together in a network, there is disclosed a system and method of transferring information from a first device in the network to a second device in the network when the first device is operating in a reduced power mode. The first device comprises a second power supply for supplying power to the first device when a first power supply fails. The first device also comprises a controller for transferring information from the first device to a second device in the network when the first device is receiving power from the second power supply. The second device in the network receives power from its own first power supply. The second device receives information that has been transferred from the first device in the network.
A DC power supply comprising a sealed lead-acid battery, a charging regulator, a discharge pass element, an output power switch for disconnected the power supply from the computer and four light-emitting diode indicators which display the condition and trend of the battery charge state. The power supply may be permanently attached to an Apple IIc brand computer without marring the computer's plastic housing by means of tabs on upper and lower projections of the power supply housing which interlock with slots on the upper and lower surfaces of the computer's housing. The power supply also features an electronic "sleep" switch which not only prevents battery drain when the power output switch is turned off, but also prevents deep discharge of the battery and possible damage to the powered equipment when battery voltage drops below a preset value while the output switch is turned on and adequate voltage from the power line is unavailable. The sleep switch disables all of the power supply's circuitry save an input-deactivated driver transistor and a CMOS logic circuit required for both disabling and reawakening the circuitry. A one-shot awakening feature is triggered for approximately one second whenever the output power switch is closed. If the battery is adequately charged, the power supply remains awake; if not, it reverts to sleep. When connected to an adequate DC source, the unit functions as an on-line uninterruptible power supply; when disconnected, the computer becomes a battery-powered portable.
A controlled battery charger for appropriately executing trickle charging for an electronic apparatus incorporating more than two batteries even when output terminal voltages of the incorporated batteries differ. A battery charger of the present invention includes a trickle charging circuit serially inserted between the output terminals of the first and the second batteries. An example of the trickle charging circuit is constituted by the first zener diode whose cathode is connected to the output terminal of the first battery, and the second zener diode whose cathode is connected to the output terminal of the second battery and whose anode is connected to the anode of the first zener diode, i.e., is constituted by two zener diodes serially connected in opposing directions. A resistor may be serially inserted between the anodes of the first and the second zener diodes. When the gap between the output terminal voltages Vbat1 and Vbat2 of the first and the second batteries becomes larger than the first or the second zener voltage Vz1 or Vz2, the trickle charging circuit enters the current-carrying state. For example, when the first battery is over-discharged and the gap between the output terminal voltages Vbat1 and Vbat2 is greater than the second zener voltage Vz2, the output terminals enter the current-carrying states, and a current flows from the second battery to the first battery until the gap of the voltage level is equal to or lower than the zener voltage Vz2. As a result, trickle charging for the first battery is performed by the second battery. The resistor inserted serially between the first and the second zener diodes controls the current volume that flows between the batteries in the current-carrying state into a microcurrent appropriate for trickle charging.
