Relay control apparatus, battery pack and electric vehicle

Patent metadata

Field	Value
Publication number	US-12370894-B2
Application number	US-202218028902-A
Country	US
Kind code	B2
Filing date	Mar 18, 2022
Priority date	Mar 18, 2021
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A relay control apparatus for a relay including a contact connected between a positive electrode of a battery and a load, and a coil connected between a relay power terminal and a ground in which the contact moves to a closed position when the coil is energized. The relay control apparatus includes a coil control switch which is turned on in response to a first switching signal having a voltage level that is equal to or higher than a first threshold voltage in response to a relay on-command, and a relay holding circuit configured to store emergency power using power supplied from the battery.

First claim

What is claimed is:

1. A relay control apparatus for a relay including a contact connected between a positive electrode of a battery and a load; and a coil connected between a relay power terminal and a ground wherein the contact moves to a closed position when the coil is energized, the relay control apparatus comprising:
a control circuit configured to output a first switching signal having a voltage level that is equal to or higher than a first threshold voltage in response to a relay on-command;
a coil control switch connected between a first terminal of the coil and the relay power terminal or between an opposite second terminal of the coil and the ground, wherein the coil control switch is configured to turn on in response to the first switching signal; and
a relay holding circuit configured to store emergency power using power supplied from the battery,
wherein the relay holding circuit is configured to output the first switching signal instead of the control circuit using the emergency power when the control circuit is unable to output the first switching signal.

2. The relay control apparatus according to claim 1 , wherein the coil control switch is an NPN transistor having a collector connected to the relay power, an emitter connected to the first or second terminal of the coil and a base connected to the control circuit.

3. The relay control apparatus according to claim 2 , wherein the relay holding circuit includes:
a voltage divider connected between the positive electrode of the battery and the ground, and configured to generate an output voltage that is less than the voltage across the battery;
a capacitor having a first terminal connected to the ground, wherein the emergency power is stored in the capacitor; and
a first auxiliary switch connected between the voltage divider and an opposite terminal of the capacitor,
wherein in response to the first auxiliary switch being turned on, the capacitor is charged by the output voltage.

4. The relay control apparatus according to claim 3 , wherein the first auxiliary switch is an NPN transistor including a collector connected to an output node of the voltage divider, an emitter connected to a second terminal of the capacitor and a base connected to the control circuit.

5. The relay control apparatus according to claim 4 , wherein the control circuit is configured to output a second switching signal having a voltage level that is equal to or higher than a second threshold voltage to the base of the first auxiliary switch in response to the relay on-command, and
wherein the first auxiliary switch is configured to turn on in response to the second switching signal being received at the base of the first auxiliary switch.

6. The relay control apparatus according to claim 3 , wherein the relay holding circuit further includes a discharge resistor connected between the base of the coil control switch and the emitter of the coil control switch.

7. The relay control apparatus according to claim 3 , wherein the relay holding circuit further includes a first diode including an anode connected to the control circuit and a cathode connected to the base of the coil control switch.

8. The relay control apparatus according to claim 7 , wherein the first diode is a light emitting diode configured to output an optical signal in response to the first switching signal being outputted by the control circuit,
wherein the first auxiliary switch is a photo transistor including a collector connected to an output node of the voltage divider, a base configured to receive the optical signal, and an emitter connected to a second terminal of the capacitor, and
wherein the first auxiliary switch is configured to turn on in response to the optical signal being received at the base of the first auxiliary switch.

9. The relay control apparatus according to claim 3 , wherein the relay holding circuit further includes a second diode including an anode connected to a second terminal of the capacitor and a cathode connected to the base of the coil control switch.

10. The relay control apparatus according to claim 3 , wherein the relay holding circuit further includes:
a second auxiliary switch which is a PNP transistor including an emitter connected to a second terminal of the capacitor, a collector connected to the base of the coil control switch and a base connected to the control circuit; and
a pull-down resistor connected between the base of the second auxiliary switch and the ground,
wherein the control circuit is configured to output a third switching signal having a voltage level that is equal to or higher than a third threshold voltage to the base of the second auxiliary switch, and
wherein the second auxiliary switch is configured to:
turn off in response to the third switching signal being outputted by the control circuit; and
turn on in response to the control circuit being unable to output the third switching signal.

11. A battery pack comprising the relay control apparatus according to claim 1 .

12. An electric vehicle comprising the battery pack according to claim 11 .

Assignees

• Lg Energy Solution Ltd

Inventors

• Choi Ho-Been
• Kim Young-Min

Classifications

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/663

  using battery or load disconnect circuits (H02J9/002 takes precedence) · CPC title

• H02J9/061

  for DC powered loads · CPC title

• H01M10/425

  Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00) · CPC title

• H01H47/32

  Energising current supplied by semiconductor device · CPC title