ELECTRICAL SUPERVISORY CONTROL

• US 3,646,354 A
• Filed: 11/05/1970
• Issued: 02/29/1972
• Est. Priority Date: 11/05/1970
• Status: Expired due to Term

• Current Assignee: Joe W. Von Brimer
• Original Assignee: Joe W. Von Brimer
• Inventors: Von Brimer, Joe W.
• Primary Examiner(s): Hohauser, Herman J.
• Application Number:
  US05/087,190
• Time in Patent Office: 481 Days
• Field of Search: 320/39,40 317/31X 307/94,9,1R,1BP
• US Class Current: 307/10.7
• CPC Class Codes: B60Q 11/00 Arrangement of monitoring devices for devices provided for in groups B60Q1/00 - B60Q9/00
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• 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: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A control circuit is connected into the electrical system of a vehicle such as an automobile having a starting motor, a battery, and various current-consuming load devices, such as headlights. A relay-operated switch is connected between the battery and the load devices. A potentiometer is connected across the battery, and the relay winding and a transistor are connected across the potentiometer with the potentiometer slider connected to the base of the transistor and the collector connected to the relay winding. The resistance values are chosen such that when the battery is substantially charged, the voltage across the baseemitter junction of the transistor is sufficient to keep the transistor conducting, thus causing the relay to be energized and the switch to be closed, connecting the load devices to the battery. Should the battery be run down, as through leaving the headlights on, the battery voltage will drop, and at some desired proportion of full charge the voltage across the base-emitter junction will become too low to keep the transistor conducting, and the relay will drop out, opening the switch and disconnecting the load devices. A reset switch is provided to reconnect the remaining battery voltage across the relay winding.

Claims

1. A circuit for monitoring an electrical system including a battery and load means connected to said battery, said circuit comprising:

switch means connected between said battery and said load means;

a voltage divider connected across said battery;

a relay having a winding and an armature connected to said switch means and a transistor, said winding and said transistor being connected in series with each other in parallel with said voltage divider;

the intermediate terminal of said voltage divider being connected to the base of said transistor such that when said battery is charged to a desired proportion of capacity the base-emitter junction voltage is sufficient to keep said transistor conducting, thereby energizing said winding and closing said switch means, and when said battery is discharged below said desired proportion of capacity, said base-emitter junction voltage drops below the value required to keep this transistor conducting and said winding is deenergized, thus opening said switch means.

2. A circuit for monitoring an electrical system as set forth in claim 1 wherein a reset switch is connected between said winding and the ground side of said battery for impressing battery voltage across said winding to thereby reclose said switch means.

3. A circuit for monitoring an electrical system as set forth in claim 1 wherein additional load means are connected between said switch means and the ground side of said battery and a normally open switch is connected between said switch means and said additional load means.

4. A circuit for monitoring an electrical system as set forth in claim 3 wherein resistance means is connected between the load side of said normally open switch and the base of said transistor, the value of said resistor being such that when said normally open switch is closed, said base-emitter junction is biased to conduction even though said battery voltage may be discharged to below said desired proportion of capacity.

5. A circuit for monitoring an electrical system as set forth in claim 1 wherein said voltage divider comprises a potentiometer having its slider connected to the base of said transistor.

6. A circuit for monitoring an electrical system including a battery and load means connected to said battery, said circuit comprising:

switch means connected between said battery and said load means;

a voltage divider connected across said battery;

a relay and a transistor having emitter base and collector electrodes connected in parallel with said voltage divider, said eMitter being connected to the ground side of said battery, said base being connected to the junction point of said voltage divider, said collector being connected to one side of the winding of said relay, and armature means actuated by energizing said winding to open and close said switch means;

said voltage divider resistance values being such that when said battery is charged to a desired proportion of capacity, the voltage across the base-emitter junction of said transistor is sufficient to keep said transistor in a conducting state, thereby energizing said winding and moving said armature to close said switch means, and when said battery is discharged below said desired proportion of capacity, said base-emitter voltage drops below the value required to keep said transistor conducting and said relay winding is deenergized, thus opening said switch means; and

normally open reset switch means connected between said winding and the ground side of said battery to energize said winding by impressing battery voltage across said winding resulting in closing said switch means.

7. A circuit for monitoring an electrical system as set forth in claim 6 wherein an additional switch is connected between said switch means and at least a portion of said load, and resistance means is connected between the load side of said switch and the base circuit of said transistor.

8. A circuit for monitoring an electrical system as set forth in claim 6 wherein an electrical motor means is connected between the load side of said switch means and the ground side of said battery, and a normally open switch is connected between said switch means and said electrical motor means.