Adaptable power supply circuit
A power supply circuit and a transponder having a circuit for rectifying an A.C. voltage and two power storage elements, the rectifying circuit providing a rectified voltage to at least one of the storage elements and an output voltage being provided by at least one of the storage elements, and at least one switching element for switching the circuit operation between a state of provision of a relatively high voltage and a state of provision of a relatively low voltage, the second state configuring the rectifying circuit in halfwave operation.
1. A power circuit comprising a circuit for rectifying an A.C. voltage and two power storage elements, the rectifying circuit providing a rectified voltage to at least one of the storage elements and an output voltage being provided by at least one of the storage elements, and comprising at least one switching element for switching the circuit operation between a first state of provision of a relatively high voltage and a second state of provision of a relatively low voltage, the second state configuring the rectifying circuit in halfwave operation.
2. The circuit of claim 1 , wherein the switching element short-circuits one of the storage elements.
3. The circuit of claim 1 , further comprising a comparator for comparing data representative of the dissipation in the supplied load with a threshold.
4. The circuit of claim 3 , wherein said comparator compares the output voltage with a predetermined threshold, greater than the maximum that can be reached by said relatively high voltage.
5. The circuit of claim 4 , wherein the threshold is settable.
6. A transponder, comprising:
a resonant circuit providing a variable voltage from an electromagnetic circuit radiated by a terminal; and
the power supply circuit of claim 1 .
7. The transponder of claim 6 , wherein said relatively high voltage is selected to be greater than the minimum operation voltage at the range limit.
8. A power circuit comprising a circuit for rectifying an A.C. voltage and two power storage elements, the rectifying circuit providing a rectified voltage to at least one of the storage elements and an output voltage being provided by at least one of the storage elements, and comprising at least one switching element for switching the circuit operation between a first state of provision of a relatively high voltage and a second state of provision of a relatively low voltage, the second state configuring the rectifying circuit in halfwave operation,
wherein the switching element short-circuits one of the storage elements, and wherein the rectifying circuit and the storage elements are respectively formed of series associations of two diodes and of two capacitors, the A.C. voltage being applied to the respective midpoints of said series associations connected in parallel.
9. The circuit of claim 8 , wherein the capacitors are of same value.