Automatic cut-out device

• US 4,137,557 A
• Filed: 02/13/1978
• Issued: 01/30/1979
• Est. Priority Date: 05/15/1974
• Status: Expired due to Term

• Current Assignee: Societa Italiana Pentole SpA
• Original Assignee: Societa Italiana Pentole SpA
• Inventors: De Lena, Oscar, Ciarniello, Giorgio
• Primary Examiner(s): Moose, Jr., Harry E.
• Application Number:
  US05/877,380
• Time in Patent Office: 351 Days
• Field of Search: 361/86, 361/90, 361/92, 361/187, 307/10 BP, 307/130, 307/362, 307/363, 340/661, 340/663, 320/39, 320/40, 320/43, 320/54
• US Class Current: 361/92
• CPC Class Codes: H02H 3/033 with several disconnections in a preferential order, e.g. following priority of the users, load repartitionH02H3/06 takes precedence
• CPC Class Codes: H02J 2310/60 Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: H02J 9/002 in which a reserve is maintained in an energy source by disconnecting non-critical loads, e.g. maintaining a reserve of charge in a vehicle battery for starting an engine
• 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: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/20 End-user application control systems
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

Abstract

A device for cutting out non-essential loads in a generator and battery-fed electric plant includes a voltage detecting unit connected across the terminals of the battery. The detecting unit may be a relay. Whenever the voltage at the terminals falls below a predetermined level, the detecting unit effects the disconnection of the non-essential load or loads from the terminals of the battery and generator, while allowing the essential load or loads. The detecting unit preferably includes a differential amplifier having one of its inputs connected to a voltage divider connected in parallel with the battery and its second input coupled to a source of reference potential.

Claims

1. A device to cut out non-essential loads in a generator and battery fed electric plant including, in addition to a circuit of essential loads, also a circuit of at least one non-essential load, said device comprising a voltage responsive means connected across terminals of said battery for opening said circuit of at least one non-essential load whenever voltage at said terminals falls below a pre-set level, said voltage responsive means including an integrated unit having means for developing a constant reference voltage and a differential amplifier;

a power transistor, said differential amplifier having its output controllably connected to said power transistor; and

a normally closed contact relay coupled to said power transistor to be activated thereby whenever the output of said differential amplifier exceeds a pre-adjustable critical level, said output being proportional to the difference between the battery voltage and said constant reference voltage.

2. A device according to claim 1, wherein said differential amplifier has its first input connected to a tap on a voltage divider connected across said terminals of said battery.

3. A device according to claim 2, wherein said tap is adjustable.

4. A device according to claim 3, wherein said differential amplifier has its second input coupled to a source of said constant reference voltage.

5. A device according to claim 4, including a further voltage divider, said further voltage divider being connected across said source of said constant reference voltage and said second input is connected to a tap on said further voltage divider.

6. A device according to claim 5, wherein said tap on said further voltage divider is fixed.

7. A device according to claim 1, wherein said voltage responsive means is directly, conductively connected across said terminals of said battery free of series connected semiconductive members.