Patent ID: 7282809
Filing Date: 2007-10-16
Classification: B60L,B60R,H02J,Y02T

Abstract:
1. An interface circuit for use between a direct-current voltage source, and a circuit for the pulsed driving of a load, in parallel with which at least one high-capacitance capacitor is connected, the interface circuit comprising: a MOSFET transistor the drain-source path of which is intended to be arranged in series between the voltage source and the circuit for driving the load in order to control the current transferred towards the load, and the gate of which is connected to control-circuit means suitable for driving the transistor in accordance with predetermined procedures, the interface circuit comprising a first supply terminal and a second supply terminal which are intended operatively to be connected to a same terminal of the voltage source, permanently and through a hand-operable switch means, respectively, the MOSFET transistor having its drain connected to the first supply terminal, the control-circuit means comprising: a circuit for controlling current conduction, which is connected to the gate of the MOSFET transistor and which, each time it receives an activation signal, is capable of bringing about an initial transitory stage in which a progressively increasing current is conducted through the transistor in accordance with a predetermined time constant whilst this transistor is operating in the linear region of its characteristic, and a subsequent or steady-state stage in which the MOSFET transistor is operating in conditions of substantial saturation, and an enabling circuit which is connected to the second supply terminal and which can keep the MOSFET transistor non-conductive and is adapted to supply an activation signal to the circuit for controlling current conduction, when the second supply terminal is disconnected from and connected to the voltage source, respectively; wherein the enabling circuit comprises a first electronic switch interposed between the gate of the MOSFET transistor and the earth and having a control input connected to the second supply input so that, when the second supply input is connected to the voltage source the first switch is non-conductive.