Long life cardiac pacer with switching power

• US 4,345,604 A
• Filed: 07/21/1980
• Issued: 08/24/1982
• Est. Priority Date: 01/22/1976
• Status: Expired due to Term

• Current Assignee: Vitatron Medical BV
• Original Assignee: Vitafin N.V.
• Inventors: Renirie, Alexis C. M.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US06/170,686
• Time in Patent Office: 764 Days
• Field of Search: 307/24, 307/29, 307/30, 307/33, 307/155, 323/242, 323/271, 323/273, 323/303, 363/59, 363/60, 363/74, 363/106, 363/111, 363/123
• US Class Current: 607/34
• CPC Class Codes: A61N 1/362 Heart stimulators heart defibrillators A61N1/39
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 3/155 using semiconductor devices only

Abstract

A switching power delivery means for use with a relatively low voltage power source, adapted to be used in conjunction with a converter for providing a raised voltage supply to a load, wherein the load is characterized by having a first circuit portion which is voltage sensitive and draws a low current, and a second circuit portion which draws a high current and is relatively insensitive to supply deviations, comprising a switching circuit alternately connecting said respective circuit portions through respective converters to the supply so that the voltage sensitive circuit is not affected by the loading of the high current circuit.

Claims

1. A self powered circuit for providing an output which is variable as a function of its available power, comprising a DC power source having characteristics subject to variation as a function of the power which it has delivered, and programmable conversion means connected to said source for converting the DC output of said source to a higher DC level, said conversion means providing a conversion which is a predetermined function of the power available from said source.

2. A self powered circuit for providing a voltage output which is variable as a function of its available power, comprising a DC power source with a DC voltage output and having an internal resistance characteristic subject to variation as a function of the power which it has delivered, and voltage conversion means connected to said source output for converting the DC voltage output of said source to said variable voltage output with a voltage conversion characteristic which is a predetermined function of said internal resistance characteristic.

3. The circuit described in claim 2, wherein said DC power source is a lithium battery having an internal resistance characteristic which has a substantially linear portion until a knee is reached, and wherein said voltage conversion characteristic is substantially constant corresponding to said substantially linear portion.

4. The combination of a lithium power source a voltage providing circuit and a load, said circuit being connected to the output of said lithium power source, said source having an internal resistance which varies with source energy depletion, and said load being connected in parallel with said circuit so as to receive power from said circuit wherein the improvement consists of

said circuit comprising means for providing a voltage conversion which is a predetermined function of said source internal resistance, and a voltage output which is variable as a function of said internal resistance and independent of said load.