Generator shorted diode protection system

In a brushless alternating current generator having a provision for shorted diode protection free from the need to detect and use field current or field current ripple to provide said protection, said generator including in combination,

• a stationary armature member and a rotatable member carrying a field winding,
• an exciter having a stationary member carrying a field winding and an armature member rotatable with said rotatable member of the generator,
• rectifier means mounted for rotation with said rotatable member and electrically connected between the exciter armature member and the generator field winding to supply direct current excitation thereto,
• means for supplying direct current to said exciter field winding,
• means for sensing a voltage difference across said exciter field and pairing said voltage difference with generator load current at the instant said voltage difference is sensed, said sensing means thereby providing an output signal that depends upon said instantaneous voltage sensed and said load current, said output signal falling within a predictable range of voltage difference values over a normal generator load current range, said output signal falling within a higher range of voltage difference values upon the occurrence of a shorted diode,
• said means for sensing said voltage difference being electrically coupled across said exciter field and including multiplexer means electrically coupled across said exciter winding and to a microprocessor means included in said means responsive to said output signals, said multiplexer means adapted to receive signals from either side of said exciter winding and a control signal from said microprocessor means,
• means responsive to said output signal such that whenever said output signal representing a voltage difference exceeds a preset value in said normal load current range, an output is generated that interrupts the energization of said exciter field.