Battery charging unit for a medical appliance

• US 5,089,763 A
• Filed: 12/11/1989
• Issued: 02/18/1992
• Est. Priority Date: 12/12/1988
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Van Der Linden, Klaus, Wunder, Siegfried
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): KINCAID, KRISTINE LYNN
• Application Number:
  US07/449,704
• Time in Patent Office: 799 Days
• Field of Search: 320/14, 320/20, 320/22, 320/23, 320/37, 320/38, 320/48
• US Class Current: 320/159
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: Y10S 320/18 Indicator or display

Abstract

A battery charging unit for a medical appliance, preferably an inhalator, includes a transformer having a high-voltage side to be connected to a mains voltage and having a low-voltage side. A rectifier is connected to the low-voltage side of the transformer. A charge current circuit is connected to the rectifier for charging a battery. A timing control is connected to the charge current circuit for switching a charge current to a value being safe for long-term charging after a predetermined period of time at an initially higher value. A test key is connected to the charge current circuit for interrupting charging of the battery and loading the battery with a given maximum current requirement for a given period of time. The voltage of the battery under load is measured and compared with a predetermined reference voltage after the test key is actuated. A control light signals if the reference voltage is exceeded.

Claims

1. Battery charging unit for a medical appliance, comprising a transformer having a high-voltage side to be connected to a mains voltage and having a low-voltage side, a rectifier connected to the low-voltage side of said transformer, a charge current circuit connected to said rectifier for charging a battery with a charge current at an initially relatively high value sufficient for storing energy required for putting the appliance into operation and keeping it in operation during a given operating cycle after a charge time of approximately three minutes, a resistor connected in series with the battery, timing control means connected to said charge current circuit for switching said resistor to a different value for obtaining a relatively low charge current safe for long-term charging after a predetermined period of time of approximately 1.5 hours, a test key connected to said charge current circuit for interrupting charging of the battery and loading the battery with a given maximum current requirement for a given period of time, a voltage regulator connected in said charge current circuit, means for measuring and comparing the voltage of the battery under load with a predetermined reference voltage after said test key is actuated, and a means connected to said measuring and comparing means for signalling if the reference voltage is exceeded, wherein the charge currents produce a full charge of the battery after a total of approximately 12 hours, and wherein the full charge of the battery is sufficient for inhalation purposes for approximately 25 inhalation cycles, when used in an ultrasound atomizer for liquids.

2. Battery charging unit according to claim 1, wherein said given period of time is two seconds.

3. Battery charging unit according to claim 1, wherein said signalling means are in the form of a light being lighted only if the reference voltage is exceeded.

4. Battery charging unit, comprising a transformer to be connected to a mains voltage, a rectifier connected to said transformer, a charge current circuit connected to said rectifier, terminals for connection to a battery to be charged, a resistance network, a first switch connected between said resistance network and said charge current circuit, a second switch connected between said resistance network and said terminals, timing control means connected to said first switch for switching from an initially high charge current value to another charge current value for long-term charging after a period of time of approximately 1.5 hours, a test key connected to said second switch for interrupting charging of the battery and loading the battery with a given maximum current requirement for a given period of time, means connected to said second switch for measuring and comparing the voltage of the battery under load with a predetermined reference voltage when said test key is actuated, and means connected to said measuring and comparing means for signalling if the reference voltage is exceeded.

5. Battery charging unit according to claim 4, including a voltage regulator connected in said charge current circuit.

6. Battery charging unit for a medical appliance, comprising a transformer having a high-voltage side to be connected to a mains voltage and having a low-voltage side, a rectifier connected to the low-voltage side of said transformer, a charge current circuit connected to said rectifier for charging a battery, timing control means connected to said charge current circuit for switching a charge current to a value for long-term charging after a predetermined period of time of approximately 1.5 hours at an initially higher value, a test key connected to said charge current circuit for interrupting charging of the battery and loading the battery with a given maximum current requirement for a given period of time, means for measuring and comparing the voltage of the battery under load with a predetermined reference voltage after said test key is actuated, and a means connected to said measuring and comparing means for signalling if the reference voltage is exceeded.

7. Battery charging unit according to claim 6, including a voltage regulator connected in said charge current circuit.