Method and circuit arrangement for preventing the stand-by discharge of a battery-powered signal evaluation circuit of a sensor

• US 6,801,015 B2
• Filed: 01/16/2003
• Issued: 10/05/2004
• Est. Priority Date: 02/01/2002
• Status: Expired due to Fees

• Current Assignee: Miele & CIE KG
• Original Assignee: Miele & CIE KG
• Inventors: Tiekoetter, Stefan, Bertram, Andre, Ennen, Guenther
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/345,687
• Publication Number:
  US 20030146739A1
• Time in Patent Office: 628 Days
• Field of Search: 320/114, 320/115, 320/125, 320/127, 320/129, 320/132, 153/39
• US Class Current: 320/127
• CPC Class Codes: A47L 9/281 the amount or condition of incoming dirt or dust
• CPC Class Codes: A47L 9/2884 Details of arrangements of batteries or their installation
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 50/574 Devices or arrangements for the interruption of current
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A circuit arrangement for preventing the discharge of a battery powering a signal evaluation circuit while the circuit is in a stand-by mode, provided with a sensor for generating signals and means responsive to the generation of signals for connecting the battery to the signal evaluation circuit and for disconnecting the battery in the absence of signals. The signal responsive means include an amplifier for triggering a monostable flip flop the output of which controls the conductivity of a transistor between the battery and the signal evaluation circuit.

Claims

1. A method of preventing the discharge of a battery during intermittent stand-by modes of a signal evaluation circuit, comprising the steps of:

generating signals derived from a sensor;

feeding the signals to a power supply switching circuit;

switching the power supply switching circuit in response to the signals to connect the battery to the signal evaluation circuit and to disconnect the battery in the absence of the signals.

2. The method of claim 1, wherein the power supply switching circuit connects the battery to the signal evaluation circuit in response to signals of a predetermined amplitude.

3. The method of claim 1, further including the step of adjusting the sensitivity of the power supply switching circuit relative to the signal strength.

4. The method of claim 1, further including the step of switching the power supply switching circuit as a function of the temporal sequence of the signals.

5. The method of claim 1, wherein the signals are generated in response to dust particles impinging upon the sensor.

6. A circuit arrangement for preventing, during a stand-by mode of a signal evaluation circuit, the discharge of a battery energizing the evaluation circuit, comprising:

a sensor for selectively generating signals;

a power supply switching circuit connected to the battery and responsive to generated signals to connect the battery to the signal evaluation circuit and to disconnect the battery from the signal evaluation circuit in the absence of signals.

7. The circuit arrangement of claim 6, wherein the power supply circuit includes a switching element disposed in the power mains of the signal evaluation circuit.

8. The circuit arrangement of claim 7, wherein the switching element is a transistor.

9. The circuit arrangement of claim 8, wherein the sensor is connected to the power supply switching circuit by an amplifier the output of which is connected to a monostable flip flop for triggering the transistor.

10. The circuit arrangement of claim 9, wherein the output of the amplifier may be modified by an R-C circuit.

11. The circuit arrangement of claim 9, wherein the output of the amplifier is connected to the monostable flip flop through a comparator for processing signals.

12. The circuit arrangement of claim 11, wherein the output of the sensor is connected to a voltage divider for adjusting the input to the comparator.

13. The circuit arrangement of claim 9, wherein for adjustment of its reset period the monostable flip flop is provided with an R-C circuit.

14. The circuit arrangement of claim 9, further comprising at least one decoupling switch between the sensor and the amplifier.

15. The circuit arrangement of claim 9, wherein the amplifier is a multistage operational amplifier.