Combined electronic ignition and alarm system

Electronic ignition and alarm system for an internal-combustion engine, of the type comprising an ignition circuit connected to a voltage generator operated to rotate in synchronism with the internal-combustion engine, the alarm system comprising an electronic read circuit for reading a coded signal emitted by an integrated circuit inside an ignition key, which can be connected both to the aforementioned coded-signal read circuit and a microcontroller for identifying the coded signal, the microcontroller having enabling signal emitting output, connected to an electronic control switch of the ignition circuit for sparking the engine ignition, wherein a power supply device having a voltage output for powering the microcontroller and the electronic read circuit is provided, said powering circuit comprising an energy storage capacitor (C3) to provide voltage supply to said voltage output, the energy storage capacitor being operationally connectable to the voltage generator via a first low-impedance circuit for charging thereof upon start-up of the engine and, respectively, via a second high-impedance circuit for holding the charged state of said capacitor during normal running of the engine, and control means for controlling the charging voltage of storage capacitor, comprising switch means in the low-impedance circuit to connect the storage capacitor to the voltage generator of the engine.