Integrated Circuit and Method for Preserving Vehicle's Battery Charge and Protecting Trailer Load

• US 20080203975A1
• Filed: 02/28/2008
• Published: 08/28/2008
• Est. Priority Date: 02/28/2007
• Status: Active Grant

• Current Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Mirowski, Marian, Burlak, Gary Joseph
• Granted Patent: US 8,134,339 B2
• Time in Patent Office: Days
• US Class Current: 320/161
• CPC Class Codes: H02H 3/12 responsive to underload or no-load for motors H02H7/0827

Abstract

A method and integrated circuit for preserving a battery'"'"'s charge and protecting electrical devices is disclosed. A maximum and a minimum battery voltage value at the output port are stored in a memory. A steady state battery voltage at the output port is measured and stored in the memory. A processor compares the measured steady battery voltage value to the maximum and the minimum battery voltage values. If the measured steady state battery voltage value is greater than the maximum battery voltage value, an over voltage state is reported by the processor. If the measured steady state battery voltage value is less than the minimum battery voltage value, a low battery voltage state is reported by the processor.

Claims

1. A method for preserving a battery'"'"'s charge and protecting electrical devices each receiving power from an output port of a respective power control circuit coupled to the battery, comprising:

storing a maximum and a minimum battery voltage value at the output port in a memory, the maximum and minimum battery voltage values being based on a hardware characteristic of the electrical device and the battery-type;

measuring a steady state battery voltage at the output port;

storing the measured steady state battery voltage value in the memory;

comparing, by a processor, the measured steady battery voltage value to the maximum and the minimum battery voltage values;

if the measured steady state battery voltage value is greater than the maximum battery voltage value, reporting an over voltage state;

if the measured steady state battery voltage value is less than the minimum battery voltage value, reporting a low battery voltage state;

in response to the over voltage state, sending by the processor a first power control signal to the power control circuit to vary the voltage or current at the output port; and

in response to the low battery voltage state, sending by the processor a second power control signal to the power control circuit to vary or remove the voltage or the current at the output port.

2. The method according to claim 1, further comprising:

determining if the electrical device is a non-critical load; and

responsive to the determination that the electrical device is a non-critical load, varying the duty cycle of the power control circuit by the second power control signal to remove electrical power from the output port.

3. The method according to claim 1, further comprising:

determining if the electrical device is a critical load; and

responsive to the determination that the electrical device is a critical load, varying the duty cycle of the power control circuit by the second power control signal to reduce the voltage at the output port.

4. The method according to claim 1, further comprising:

determining if a trailer is connected to the vehicle; and

removing electrical power from one or more output ports if a trailer is not connected to the vehicle.

5. The method according to claim 1, further comprising:

determining if the vehicle is in a sleep mode, wherein during the sleep mode the vehicle battery provides electrical power to an attached trailer while the vehicle'"'"'s engine and electrical loads are turned off;

responsive to the determination that the vehicle is in a sleep mode, measuring the voltage at the output port;

comparing the measured voltage to the minimum battery voltage; and

reducing the voltage at the output port by varying the duty cycle of the power control circuit by the second power control signal if the measured voltage is less than the minimum battery voltage.

6. The method according to claim 1, further comprising:

determining the type of the electrical device; and

responsive to the type of the electrical device, varying the duty cycle of the power control circuit by the second power control signal.

7. The method according to claim 1, wherein the processor, the memory and the power control circuit are implemented in a trailer tow connector configured to provide electrical power to a trailer attached to the vehicle.

8. A method for monitoring a battery'"'"'s charge and protecting electrical devices each receiving power from an output port of a respective power control circuit coupled to the battery, comprising:

storing a maximum battery voltage value at the output port in a memory, the maximum battery voltage value being based on the hardware characteristic of the electrical device at the output port and the battery-type;

measuring a steady state battery voltage at the output port;

storing the measured steady state battery voltage value in the memory;

comparing, by a processor, the measured steady battery voltage value to the maximum battery voltage value;

if the measured steady state battery voltage value is greater than the maximum battery voltage value, reporting an over voltage state; and

in response to the over voltage state, sending by the processor a power control signal to the power control circuit to vary the voltage or current at the output port.

9. The method according to claim 8, further comprising:

determining the type of electrical device connected to the output port; and

responsive to the type of electrical device, varying the duty cycle of the power control circuit by the power control signal to reduce the voltage at the output port.

10. The method according to claim 8, further comprising:

determining the type of electrical device connected to the output port; and

responsive to the type of electrical device, varying the duty cycle of the power control circuit by the power control signal to reduce the current flowing in the electrical device.

11. The method according to claim 8, further comprising:

determining the type of electrical device connected to the output port; and

responsive to the type of electrical device, varying the duty cycle of the power control circuit by the power control signal to reduce the power flowing in the electrical device.

12. The method according to claim 8, further comprising:

determining if the power control circuit is configured as an open loop system; and

varying the duty cycle of the power control circuit by the power control signal to a pre-selected first duty cycle if the power control circuit is configured as an open loop system.

13. The method according to claim 8, further comprising:

determining if the power control circuit is configured as a closed loop system; and

varying the duty cycle of the power control circuit by the power control signal until the voltage at the output port is equal to a pre-selected first voltage.

14. The method according to claim 8, further comprising:

determining if the power control circuit is configured as a closed loop system; and

varying the duty cycle of the power control circuit by the power control signal until the current flowing in the electrical device is equal to a pre-selected first current.

15. A method for preserving a vehicle'"'"'s battery charge, the battery providing electrical power to electrical devices each receiving power from an output port of a respective power control circuit coupled to the battery, comprising:

storing a minimum battery voltage value at the output port in a memory, the minimum battery voltage value being based on a hardware characteristic of the electrical device at the output port and the battery-type;

measuring a steady state battery voltage at the output port;

storing the measured steady state battery voltage value in the memory;

comparing, by a processor, the measured steady battery voltage value to the minimum battery voltage value;

if the measured steady state battery voltage value is less than the minimum battery voltage value, reporting a low battery voltage state; and

in response to the low battery voltage state, sending by the processor a power control signal to the power control circuit to vary the voltage or current at the output port.

16. The method according to claim 15, further comprising:

determining if the electrical device is a non-critical load; and

responsive to the determination that the electrical device is a non-critical load, varying the duty cycle of the power control circuit by the power control signal to remove electrical power from the output port.

17. The method according to claim 15, further comprising:

determining if the electrical device is a critical load; and

responsive to the determination that the electrical device is a critical load, varying the duty cycle of the power control circuit by the power control signal to reduce the voltage or current at the output port.

18. The method according to claim 15, further comprising:

determining if a trailer is connected to the vehicle; and

removing electrical power from the output ports if a trailer are not connected to the vehicle.

19. The method according to claim 15, further comprising:

determining if the vehicle is in a sleep mode, wherein during the sleep mode the vehicle battery provides electrical power to an attached trailer while the vehicle'"'"'s engine and vehicle loads are turned off;

responsive to the determination that the vehicle is in a sleep mode, measuring the voltage at the output port;

comparing the measured voltage to the minimum battery voltage; and

reducing the voltage at the output port by varying the duty cycle of the power control circuit by the power control signal if the measured voltage is less than the minimum battery voltage.

20. An integrated circuit device for preserving a battery'"'"'s charge and protecting electrical devices each receiving power from an output port of a respective power control circuit coupled to the battery, comprising:

a memory;

a processor electrically coupled to the memory, the processor storing data in, and receiving data from, the memory;

a switched power control circuit electrically coupled to the electrical device, the switched power control circuit controlling the electrical power delivered to the electrical device by varying a duty cycle responsive to a power control signal from the processor;

a voltage sense circuit electrically coupled to the load, the voltage sense circuit measuring the voltage at the output port and providing a voltage sense signal representative of the measured voltage to the processor; and

the processor storing data representative of the voltage sense signal in the memory, the processor providing the power control signal to the switched power control circuit responsive to the voltage sense signal, the processor comparing the measured voltage to a maximum and a minimum battery voltage values stored in the memory, the processor reporting an over voltage state if the measured voltage exceeds the maximum battery voltage, the processor reporting a low battery voltage if the measured voltage is less than the minimum battery voltage.

21. The integrated circuit device of claim 20, wherein the power control signal is a pulse width modulated signal for controlling the duty cycle of the switched power control circuit.

22. The integrated circuit device of claim 20, further comprising varying, by the processor, the duty cycle of the switched power control circuit to reduce voltage, current or power at the output port responsive to the voltage sense signal indicating that the measured voltage exceeds the maximum battery voltage.

23. The integrated circuit device of claim 20, further comprising varying, by the processor, the duty cycle of the switched power control circuit to reduce power at the output port responsive to the voltage sense signal indicating that the measured voltage is less than the minimum battery voltage.

24. A method for controlled recharging of a trailer battery by a vehicle battery for prolonging the life of the trailer battery, the vehicle battery delivering power to the trailer battery via an output port of a power control circuit coupled to the vehicle battery, comprising:

determining if a trailer battery is electrically coupled to the vehicle battery;

reporting a trailer battery present status if a trailer battery is electrically coupled to the vehicle battery;

storing a maximum trailer battery recharge rate in a memory, the maximum trailer battery recharge rate being the maximum permissible vehicle charging rate of the trailer battery and being based on the characteristic of the trailer battery;

measuring a steady state trailer battery discharge rate, the steady state trailer battery discharge rate being based on one or more electrical devices powered by the trailer battery;

storing, in the memory, the measured steady state trailer battery discharge rate;

comparing the measured steady state trailer battery discharge rate to the maximum trailer battery recharge rate; and

if the measured trailer battery discharge rate is greater than the maximum trailer battery recharge rate, sending by a processor a first and a second power control signal to the power control circuit to alternately recharge the trailer battery at a first and a second rate respectively.

25. The method according to claim 24, further comprising alternately recharging the trailer battery at the first rate during a first time period and at the second rate during a second time period.

26. The method according to claim 24, further comprising:

repeatedly alternately recharging the trailer battery at the first rate for a first time period and at the second rate for a second time period until the trailer battery exceeds a normal operating voltage.