Low voltage alternator having short circuit protection

摘要

In case of short circuit the overcurrent which passes through a detecting resistance in series with the excitation winding of the alternator operates a threshold current generator, which reduces the voltage of the central node of a voltage divider. A trigger interposed between said central node and an actuator circuit (for example a Darlington circuit) placed in series with the excitation winding of the alternator and with the above mentioned resistance turns off said actuator circuit, thus interrupting the current passage through the excitation winding. A filtering condenser associated to the voltage divider restores with delay the initial condition. The cycle is periodically repeated until the short circuit condition remains.