SELF-DISCHARGING CIRCUIT

• US 20160111909A1
• Filed: 11/17/2014
• Published: 04/21/2016
• Est. Priority Date: 10/21/2014
• Status: Active Grant

• Current Assignee: Quanta Computer
• Original Assignee: Quanta Computer
• Inventors: Kuo, Hsin-Chin
• Granted Patent: US 10,135,276 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices

Abstract

A self-discharging circuit discharging electrical charges of an external energy storage device coupled to a power transmission line coupled between a power supply device and a load is provided. The self-discharging circuit includes a current-limiting unit, an internal energy storage unit, a voltage detection unit and a discharge unit. The current-limiting unit is coupled between the power transmission line and a first node. The internal energy storage unit is coupled between the first node and a ground node. The ground node receives a ground level. The voltage detection unit detects a level of the first node. The discharge unit is coupled between the power transmission line and a second node. When the level of the first node is less than a pre-determined level, the voltage detection unit directs the second node to couple to the ground node.

Claims

1. A self-discharging circuit discharging an electrical charge of an external energy storage device coupled to a power transmission line coupled between a power supply device and a load, comprising:

a current-limiting unit coupled between the power transmission line and a first node;

an internal energy storage unit coupled between the first node and a ground node,

wherein the ground node receives a ground level;

a voltage detection unit detecting a level of the first node; and

a discharge unit coupled between the power transmission line and a second node,

wherein when the level of the first node is less than a pre-determined level, the voltage detection unit directs the second node to couple to the ground node.

2. The self-discharging circuit as claimed in claim 1, wherein when the level of the first node is greater than the pre-determined level, the current-limiting unit is turned on to charge the internal energy storage unit.

3. The self-discharging circuit as claimed in claim 1, wherein the current-limiting unit is a diode.

4. The self-discharging circuit as claimed in claim 3, wherein an anode of the diode is coupled to the power transmission line, and a cathode of the diode is coupled to the first node.

5. The self-discharging circuit as claimed in claim 1, wherein the discharge unit is a resistor.

6. The self-discharging circuit as claimed in claim 1, wherein the load is a real time clock (RTC).

7. The self-discharging circuit as claimed in claim 1, wherein the internal energy storage unit is a capacitor.

8. The self-discharging circuit as claimed in claim 7, wherein a capacitance of the capacitor is within 100 nF˜

200 nF.

9. The self-discharging circuit as claimed in claim 1, wherein when the second node is directed to couple to the ground node, the discharge unit discharges the external energy storage device such that a voltage stored in the external energy storage device is 0V.

10. The self-discharging circuit as claimed in claim 1, wherein the external energy storage device is a capacitor, and a capacitance of the capacitor is greater than 1 uF.