Chopper-amplifier for the voltage of a photovoltaic power source, in particular for a timepiece
First Claim
1. A voltage booster for a low voltage supplied by a photovoltaic cell arranged to be applied to a load, said voltage booster including an inductor coil connected in series with a blocking diode between said cell and said load, the node between said inductor coil and said diode being connected to the common node between said cell and said load via a switchable semi-conductor component;
- said voltage booster also including regulating means for applying a pulse control signal to said switchable semi-conductor component whose duty cycle is adjustable so that the voltage across the terminals of said cell is substantially equal to a predetermined voltage substantially corresponding to the maximum value of a voltage-power characteristic curve of said cell,wherein said regulating means include a comparator for comparing the voltage across the terminals of said cell to a reference voltage equal to said predetermined voltage and further include a circuit connected to said comparator for generating said control signal capable of varying the value of said duty cycle according to whether the voltage across the terminals of said cell is less than or greater than said reference voltage.
1 Assignment
0 Petitions
Accused Products
Abstract
In this booster, the voltage across the terminals of the photovoltaic power source (1) is regulated as a function of a reference voltage (Vref) which is chosen to be substantially equal to the voltage corresponding to the maximum value of the voltage-power curve of this source. The reference voltage generated in the reference generator (9) is compared to the voltage (Vsc) of the source (1), the result is sampled and influences the duty cycle of a control signal (Fc) applied to the switching transistor (7). The latter is responsible for chopping the current flowing from the source to the load (accumulator 6) through an inductor coil (4) and a diode (5).
-
Citations
7 Claims
-
1. A voltage booster for a low voltage supplied by a photovoltaic cell arranged to be applied to a load, said voltage booster including an inductor coil connected in series with a blocking diode between said cell and said load, the node between said inductor coil and said diode being connected to the common node between said cell and said load via a switchable semi-conductor component;
- said voltage booster also including regulating means for applying a pulse control signal to said switchable semi-conductor component whose duty cycle is adjustable so that the voltage across the terminals of said cell is substantially equal to a predetermined voltage substantially corresponding to the maximum value of a voltage-power characteristic curve of said cell,
wherein said regulating means include a comparator for comparing the voltage across the terminals of said cell to a reference voltage equal to said predetermined voltage and further include a circuit connected to said comparator for generating said control signal capable of varying the value of said duty cycle according to whether the voltage across the terminals of said cell is less than or greater than said reference voltage. - View Dependent Claims (2, 3, 4, 5)
- said voltage booster also including regulating means for applying a pulse control signal to said switchable semi-conductor component whose duty cycle is adjustable so that the voltage across the terminals of said cell is substantially equal to a predetermined voltage substantially corresponding to the maximum value of a voltage-power characteristic curve of said cell,
- 6. A voltage booster according to claim 6, wherein said regulating means include an up/down counter which is connected to said sampling means and whose content varies as a function of the result of the comparison effected by said comparator, means for generating a plurality of pulse signals of different frequencies and a combinatorial logic connected to the output of said up/down counter and to said generator means and capable of establishing said duty cycle as a function of the content of said up/down counter.
Specification