Charging circuit with current regulation

• US 9,219,376 B2
• Filed: 09/01/2010
• Issued: 12/22/2015
• Est. Priority Date: 09/03/2009
• Status: Expired due to Fees

• Current Assignee: Philips Lighting Holding BV (Signify N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Schneider, Gerhard
• Primary Examiner(s): Muralidar, Richard V
• Application Number:
  US13/390,426
• Publication Number:
  US 20120139502A1
• Time in Patent Office: 1,938 Days
• Field of Search: 320/167, 320/103, 320/145
• US Class Current: 1/1
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00718 in response to charge current gradient
• CPC Class Codes: H02J 7/007184 in response to battery voltage gradient
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices

Abstract

The present invention relates to a charging circuit (20) for charging an energy storage element (30). The charging circuit (20) comprises a feedback module (201), a controlling module (202), a switching module (203) and a storage module (204), wherein the controlling module (202) is configured to adjust the control signal so as to increase the ON-OFF ratio of the switching module (203) when the feedback signal is substantially smaller than a reference signal, or to adjust the control signal so as to decrease the ON-OFF ratio of the switching module (203) when the feedback signal is substantially larger than a reference signal. By applying the charging circuit (20), the charging time for the energy storage element (30) is shorter and therefore less power from the power source (10) is consumed.

Claims

1. A charging circuit comprising:

feedback module;

a controlling module;

a switching module; and

a storage module;

wherein

the feedback module is configured to generate a feedback signal which is fed to the controlling module on the basis of an input current drawn from a power source;

the controlling module is configured to generate a control signal on the basis of the feedback signal to control the switching module;

the storage module is configured to receive the input current drawn from the power source when the switching module is ON, and provide an output current to charge an energy storage element when the switching module is OFF; and

the controlling module is further configured to adjust the control signal so as to increase the ON-OFF ratio of the switching module when the feedback signal is substantially smaller than a reference signal, or to adjust the control signal so as to decrease the ON-OFF ratio of the switching module when the feedback signal is substantially larger than the reference signal.

2. The charging circuit of claim 1, wherein the feedback module comprises:

an impedance arranged between the power source and the switching module, wherein the input current flows through the impedance;

a voltage measuring element configured to measure a first voltage across the impedance and generate the feedback signal on the basis of the first voltage.

3. The charging circuit of claim 2, wherein the voltage measuring element comprises a differential amplifier configured to amplify the first voltage across the impedance and output the amplified first voltage as the feedback signal to the controlling module.

4. The charging circuit of claim 1, further comprising a charging controlling module, wherein the charging controlling module is configured to control the storage module to stop charging the energy storage element when the charging voltage across the energy storage element is larger than a predetermined voltage threshold.

5. The charging circuit of claim 4, wherein the charging controlling module comprises a comparator configured to compare the charging voltage across the energy storage element with the predetermined voltage threshold, and to control the controlling module to stop generating the control signal when the charging voltage across the energy storage element is larger than the predetermined voltage threshold.

6. The charging circuit of claim 1, wherein the energy storage element comprises a supercapacitor or a fast-chargeable Li-Ion battery.

7. The charging circuit of claim 1, further comprising an anti-flowing-back module arranged between the storage module and the energy storage element and configured to prevent current flowing back from the energy storage element into the storage module when the power source is OFF.

8. The charging circuit of claim 1, wherein the switching module comprises a MOSFET or a Bipolar Junction Transistor.

9. The charging circuit of claim 1, wherein the storage module is an inductor.

10. The charging circuit of claim 1, wherein the control signal is a PWM signal or a PFM signal.

11. The charging circuit of claim 3, wherein the feedback signal is a product of the input current drawn from the power source, a value of the impedance, and an amplification factor of the differential amplifier.

12. The charging circuit of claim 11, wherein the reference signal is equal to a product of the current limit of the power source, a value of the impedance, and an amplification factor of the differential amplifier.

13. The charging circuit of claim 1, wherein the reference signal is equal to a current limit of the power source.