Electronic interface for electromagnetic energy recuperation

A wireless switch system, comprising:

• an electromagnetic energy harvesting stage,
• an electronic interface circuit arranged at the output of the electromagnetic energy harvesting stage,
• a load stage at the output of said electronic interface circuit, the load stage being provided with a means for storing electrical charges and with an RF emitter provided for emitting an RF signal according to the filling of said means for storing electrical charges,
• wherein said electronic interface circuit comprises:
• an AC/DC converter for converting an input signal between a first terminal and a second terminal connected at the output of said harvesting stage, and producing a DC signal at the input of the load stage, the converter being provided with a rectifier for producing a rectified signal to said means for storing electrical charges,
• a first switch, arranged between the first terminal and the second terminal and capable of alternately connecting or disconnecting the first terminal and the second terminal from one another, the closed or open state of the first switch being governed by a first command signal,
• a second switch, disposed between an output of the rectifier and the load stage and capable of alternately connecting or disconnecting the output of the rectifier from said load stage, the open or closed state of the second switch being governed by a second command signal,
• the electronic interface circuit being further provided with a logic control block configured to produce said first command signal and said second command signal, the control block being capable of alternately switching said switches from a first configuration to a second configuration and from the second to the first configuration,
• the first configuration being a configuration wherein the first switch is open and the second switch is closed, so that said first terminal and said second terminal are disconnected and the output of said rectifier is connected to said means for storing electrical charges,
• the second configuration being a configuration wherein the first switch is closed and the second switch is open so as to disconnect the output of the rectifier from said load stage and connect the first terminal and the second terminal to each other,
• said logic control block being further configured, in a given operating mode of said circuit, to trigger an alternation between said first configuration and said second configuration several times.

An electronic interface circuit for electromagnetic energy harvesting, to be disposed between an electromagnetic energy harvesting stage and a load stage, the electromagnetic energy harvesting stage having an equivalent electrical circuit provided in series with an alternating voltage generator, an inductance L and an output impedance, the generator producing an alternating AC signal resulting from a conversion of mechanical energy into electromagnetic energy, the load stage being provided with a means for storing electrical charges, particularly a capacitance,

• said electronic interface circuit comprising:
• an AC/DC converter for converting an input signal between a first terminal and a second terminal connected at the output of said harvesting stage, and producing a DC signal at the input of the load stage, the converter being provided with a rectifier for producing a rectified signal to said means for storing electrical charges,
• a first switch, arranged between the first terminal and the second terminal and capable of alternately connecting or disconnecting the first terminal and the second terminal from one another, the closed or open state of the first switch being governed by a first command signal,
• a second switch, disposed between an output of the rectifier and the load stage and capable of alternately connecting or disconnecting the output of the rectifier from said load stage, the open or closed state of the second switch being governed by a second command signal,
• the electronic interface circuit being further provided with a logic control block configured to produce said first command signal and said second command signal, the control block being capable of alternately switching said switches from a first configuration to a second configuration and from the second to the first configuration,
• the first configuration being a configuration wherein the first switch is open and the second switch is closed, so that said first terminal and said second terminal are disconnected and the output of said rectifier is connected to said means for storing electrical charges,
• the second configuration being a configuration wherein the first switch is closed and the second switch is open so as to disconnect the output of the rectifier from said load stage and connect the first terminal and the second terminal to each other,
• said logic control block being further configured, in first operating mode of said circuit, to trigger said first configuration,
• said logic control block being further configured, in a second operating mode of said circuit, to trigger an alternation between said first configuration and said second configuration several times,
• said logic control block being further configured, to trigger a transition from said first operating mode to said second operating mode when an output voltage across said means for storing electrical charges exceeds a threshold value.