Battery, electrical equipment, and a powering method implementing means for short-circuiting the battery

• US 20070160900A1
• Filed: 12/21/2006
• Published: 07/12/2007
• Est. Priority Date: 12/22/2005
• Status: Active Grant

• Current Assignee: Safran Electronics & Defense
• Original Assignee: Sagem Defense Securite SA (Safran SA)
• Inventors: Nollet, Michel
• Granted Patent: US 8,268,465 B2
• Time in Patent Office: Days
• US Class Current: 429/50
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

The present invention relates to a method of supplying electrical power to an equipment by means of a battery, said method including the step of short-circuiting the battery until it has a temperature greater than a predetermined threshold, characterized in that the battery is short-circuited with a temporal duty ratio determined to keep the equipment functioning and to maintain the temperature of the battery above the predetermined threshold. The invention also relates to a battery and an electrical equipment for implementing that method.

Claims

1. A method of supplying electrical power to an equipment by means of a battery (1, 13), said method including the step of short-circuiting the battery until it has a temperature greater than a predetermined threshold, characterized in that the battery is short-circuited with a temporal duty ratio determined to keep the equipment functioning and to maintain the temperature of the battery above the predetermined threshold.

2. Method according to claim 1, wherein the duty ratio τ

is such that;

τ

×

P_cc+(1−

τ

) P_Ieq=Δ

t/R_thB wherein τ

is the duty ratio, P_cc is the power dissipated in the battery when short-circuited, P_Ieq is the power dissipated in the battery when supplying the equipment, Δ

t is the temperature raising necessitated to allow the battery to supply the equipment and R_thB is the resistance of the battery.

3. Electrical equipment for implementing the method of claim 1, including a power supply circuit having connection elements for connection to terminals of at least one battery and a switch member disposed between the connection elements and arranged to be suitable for being controlled with a duty ratio to go between a shorting-circuiting state in which it connects the connection elements to each other, and a disconnection state in which it disconnects the connection elements from each other, the switch member being connected to a temperature detector for detecting the temperature of the battery, so as to go over from the short-circuiting state to the disconnection state at a battery temperature that is greater a predetermined threshold.

4. Electrical equipment according to claim 2, wherein the power supply circuit comprises an input capacitor.

5. Electrical equipment according to claim 4, wherein a power diode is mounted between the battery and the input capacitor.

6. Electrical equipment according to claim 4, wherein a MOSFET transistor is mounted between the battery and the input capacitor and is controlled using a “

synchronous rectification”

method to constitute the switch member.

7. Electrical equipment according to claim 3, wherein the switch member is connected to a control circuit for controlling the switch member according to a set-point representative of the temperature threshold.

8. Electrical equipment according to claim 7, wherein the control circuit is a pulse-width-modulation circuit having an output constituting a conduction command for the switch member.

9. A battery for implementing the method of claim 1, characterized in that it includes a short-circuiting member arranged to be suitable for being controlled with a duty ratio to go between a normal operating state in which the battery operates normally, and a short-circuiting state in which the battery is short-circuited, the shorting-circuiting member being connected to a temperature detector for detecting the temperature of the battery, so as to go over from the short-circuiting state to the normal operating state at a battery temperature that is greater than a predetermined threshold.