Device for enabling an accumulator to be recharged from a source of electrical energy

• US 4,134,057 A
• Filed: 11/30/1976
• Issued: 01/09/1979
• Est. Priority Date: 12/10/1975
• Status: Expired due to Term

• Current Assignee: Ebauches SA
• Original Assignee: Ebauches SA
• Inventors: Portmann, Hubert
• Primary Examiner(s): Hickey, Robert J.
• Application Number:
  US05/746,124
• Time in Patent Office: 770 Days
• Field of Search: 323/15, 363/59, 363/60, 363/61, 320/2, 320/3, 320/9, 320/14, 320/15, 320/22, 320/31, 320/35, 320/39, 320/40, 320/61, 320/21, 320/DIG. 1, 320/1, 58/23 C, 58/23 BA
• US Class Current: 320/102
• CPC Class Codes: G04C 10/02 the power supply being a radioactive or photovoltaic source
• CPC Class Codes: G04G 19/04 Capacitive voltage division or multiplication
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: Y10S 136/291 Applications
• CPC Class Codes: Y10S 320/22 Line impedance, e.g. resistor
• CPC Class Codes: Y10S 323/906 Solar cell systems

Abstract

A device for enabling an accumulator to be recharged from a source of electrical energy, such as photo-cells. The device includes a converter circuit and a diode, the converter circuit being capable of adapting the current and voltage supplied by said source to the charging conditions of the accumulator. The converter circuit is arranged to be saturated from a certain value of the current delivered by the source, the stronger currents passing directly through the diode.

Claims

1. A device for enabling the recharging of an accumulator having two terminals with a current from a source capable of transforming an incident energy into electrical energy, the source having at least two terminals, said device comprising

diode means directly connected between the source and the accumulator for enabling the recharging of the accumulator directly from the source when the latter exceeds a predetermined value;

and

converter circuit means directly connected in parallel with said diode means between the source and the accumulator and comprising,

storage means for storing electrical energy when connected to the source and for providing electrical energy when connected to the accumulator,

a first input terminal,

a second input terminal, said first and second input terminals being directly connected to the terminals of the source,

an output terminal connected to one of the terminals of the accumulator,

switching means capable of being periodically operated for connecting in a first position thereof said input terminals, and hence said source, to said storage means in parallel therewith for the charging of said storage means, and for connecting in a second position of said switching means said charged storage means to said second input terminal and said output terminal, and hence connecting said charged storage means directly in series between the source and the accumulator;

said converter means delivering a charging current to the accumulator when the voltage at the output terminal exceeds the voltage of the accumulator; and

said diode means when said switching means is in a first position thereof for preventing a reverse current being delivered to said storage means and the source by the accumulator when the voltage of the accumulator exceeds the voltage of the source.

2. A device according to claim 1, wherein the said converter means comprises two output terminals, and at least two switching means, each switching means having two positions and said switching means being respectively connected to said input and output terminals, and said storage means comprises at least one capacitor which is connected between said switching means;

and further comprising a control means for periodically and synchronously actuating said switching means at a predetermined frequency as a result of a signal generated outside said converter means being applied to said control means such that in one of said two positions of said switching means, said capacitor is connected directly in parallel with the source and in the other position of said switching means said capacitor is connected in series with the source and with the accumulator.

3. A device according to claim 2 in which the said switching means are constructed using semi-conductor elements.

4. A device according to claim 1, wherein said converter means further comprises two output terminals, and said storage means comprises an inductance that is connected to said switching means;

and further comprising a control means for periodically actuating said switching means at a predetermined frequency as a result of a signal generated outside said converter means being applied to said control means such that in one of said two positions said inductance is connected directly in parallel with the source and in the other position said inductance is connected in series with the source and with the accumulator.

5. A device according to claim 4 in which the duty cycle of the said signal is variably applied to said control means as a function of the incident energy received by the said source.

6. A device according to claim 4 in which the said switching means is constructed using semi-conductor elements.

7. A device for enabling the recharging of an accumulator by means of a current from a source capable of transforming an incident energy into electrical energy, said source having at least two terminals, said device comprising

diode means;

and

converter circuit means comprising

at least two inputs and one output, said two inputs being connected to the terminals of the source, said diode means being connected between one of said inputs and said output,

at least one assembly formed by a capacitor and a plurality of switch means having two positions, at least two of the switch means being synchronously controllable at a predetermined frequency and connected so that in one of said two positions said capacitor is connected in parallel with the source, and in the other position said capacitor is connected in series with the source and with the accumulator, and

a third switch means having two positions for connecting and disconnecting said capacitor and the accumulator; and

a measurement circuit connected to said capacitor for receiving the sum of the voltages of the source and of said capacitor when they are connected in series, for keeping said third switch in its first position when said sum of the voltages is greater than the voltages of the accumulator, thus enabling the recharging of the accumulator, and for switching said third switch to its second position disconnecting the accumulator from the capacitor when said sum of the voltages is less than the voltage of the accumulator, thus preventing the discharge of the accumulator into said capacitor.

8. A device according to claim 7 in which the said switch means are constructed using semi-conductor elements.

9. A device for enabling the recharging of an accumulator having two terminals said device comprising

a photosensitive source capable of transforming an incident energy into electrical energy, the source having at least two terminals;

diode means directly connected between said source and the accumulator for enabling the recharging of the accumulator directly from said source when the latter exceeds a predetermined value; and

converter circuit means directly connected in parallel with said diode means between said source and the accumulator and comprised of elements integrated in an integrated circuit, said converter circuit means comprising,

storage means for storing electrical energy when connected to said source and for providing electrical energy when connected to the accumulator, said storage means having two terminals,

a first input terminal,

a second input terminal, said first and second input terminals being directly connected to the terminals of said source,

an output terminal connected to one of the terminals of the accumulator,

switching means capable of being periodically operated for connecting in a first position thereof said input terminals, and hence said source, to said storage means in parallel therewith for the charging of said storage means, and for connecting in a second position of said switching means said charged storage means to said second input terminal and said output terminal, and hence connecting said charged storage means directly in series between said source and the accumulator, said switching means comprised of semi-conductor transistors that are capable of limiting the current therethrough when saturated; and

said diode means when said switching means is in a first position thereof for preventing a reverse current being delivered to said storage means and said source by the accumulator when the voltage of the accumulator exceeds the voltage of said source.

10. A device according to claim 9 and further comprising means for generating a control signal having a predetermined frequency;

wherein said converter circuit means further includes a second output terminal directly connected to said one source terminal, said diode means being connected between said output terminals; and

wherein said switching means comprises first and second switch means, said first switch means comprising a first transistor and a second transistor, said first transistor directly connected between said first input terminal and said one storage means terminal and said second transistor directly connected between said one storage means terminal and said second input terminal, and said second switch means comprising a third transistor and a fourth transistor, said third transistor directly connected between said second storage means terminal and said first output terminal and said fourth transistor directly connected between said second storage means terminal and said second output terminal;

said generating means being connected to the control input of at least said first, second and fourth transistors for the periodic switching thereof.