Electronic circuit for a small electric appliance

• US 8,310,199 B2
• Filed: 12/01/2006
• Issued: 11/13/2012
• Est. Priority Date: 12/14/2005
• Status: Expired due to Fees

• Current Assignee: Braun GmbH (The Procter & Gamble Company)
• Original Assignee: Braun GmbH (The Procter & Gamble Company)
• Inventors: Lepper, Joachim, Schiebahn, Matthias, Klemm, Torsten
• Primary Examiner(s): Dunn, Drew A
• Assistant Examiner(s): Chung, Steve T
• Application Number:
  US12/097,472
• Publication Number:
  US 20090179614A1
• Time in Patent Office: 2,174 Days
• Field of Search: 320/108, 320/114, 320/115, 320/136, 310/50
• US Class Current: 320/108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition

Abstract

An electronic circuit for an electric appliance. In one embodiment, there is provided an electronic circuit for a battery-operated electric appliance, which can be inductively fed by an external electric power source, comprising a charging circuit for charging an accumulator (A), which encompasses a charging coil (L2) and a diode (D2), wherein the accumulator (A) is connected in series to the diode (D2) and the charging coil (L2), a light emitting diode (LED) as display for the charging process and/or charging status of the accumulator (A), wherein an end of the charging coil (L2) is connected to the cathode of the diode (D2) and the anode of the light emitting diode (LED) and the negative pole of the accumulator (A) is connected to the anode of the diode (D2).

Claims

1. An electronic circuit for a battery-operated electric appliance, which can be inductively fed by an external electric power source, comprising:

a charging circuit for charging an accumulator (A), which encompasses a charging coil (L2) and a diode (D2), wherein the accumulator (A) is connected in series to the diode (D2) and the charging coil (L2),

a light emitting diode (LED) as display for the charging process and/or charging status of the accumulator (A),

wherein an end of the charging coil (L2) is connected to the cathode of the diode (D2) and the anode of the light emitting diode (LED) and the negative pole of the accumulator (A) is connected to the anode of the diode (D2).

2. The electronic circuit of claim 1, comprising:

a controllable switch (S), coupled to the light emitting diode; and

a control circuit (uC) coupled to the controllable switch and configured to turn the light emitting diode (LED) on and off.

3. The electronic circuit of claim 2, comprising:

an electronic switch (T1), controllable by the control circuit (uC) and configured to complete the charging process of the accumulator (A).

4. The electronic circuit of claim 3 wherein,

the control circuit (uC) is configured to turn on the light emitting diode (LED) during the charging of the accumulator (A).

5. The electronic circuit of claim 1, comprising:

a second charging coil (L1) and a second diode (D1), which are configured to operate with the diode (D2) and the charging coil (L2) to form a full-wave rectifier.

8. The electronic circuit of claim 3 wherein,

the control circuit (uC) turns on the light emitting diode (LED) after the completion of the charging process of the accumulator (A).

6. An electronic circuit for a battery-operated electric appliance, comprising:

a charging coil (L2) for generating a charging current;

a load (M);

a bridge circuit, coupled to the load, the bridge circuit including a plurality of electronic switches (T1, T2, T3, T4), wherein a protective diode is connected in parallel to at least one electronic switch (T3), and

an accumulator (A) connected in series to the protective diode and the charging coil (L2), so that charging current supplied by the charging coil (L2) flows through the protective diode.

7. The electronic circuit of claim 6, wherein,

at least one of the plurality of electronic switches (T1, T2, T3, T4) comprises a MOSFET having a protective diode.

9. An electronic circuit for a battery-operated electric appliance, which can be inductively fed by an external electric power source, comprising:

a charging circuit for charging an accumulator (A), which encompasses a charging coil (L2) and a diode (D2), wherein the accumulator (A) is connected in series to the diode (D2) and the charging coil (L2),

a light emitting diode (LED) as display for the charging process and/or charging status of the accumulator (A),

wherein an end of the charging coil (L2) is connected to the cathode of the diode (D2) and the anode of the light emitting diode (LED).

10. The electronic circuit according to claim 9, comprising:

a controllable switch (S), coupled to the light emitting diode; and

a control circuit (uC) coupled to the controllable switch, and configured to turn the light emitting diode (LED) on and off.

11. The electronic circuit of claim 10, comprising:

an electronic switch (T1), which can be controlled by the control circuit (uC) configured to complete the charging process of the accumulator (A).

12. The electronic circuit of claim 11 wherein,

the control circuit (uC) turns on the light emitting diode (LED) during the charging of the accumulator (A).

13. The electronic circuit of claim 9, comprising:

charging coil (L1) and a second diode (D1), which are configured to operate with the diode (D2) and the charging coil (L2) to form a full-wave rectifier.