Load response control and method

A regulator responsive to an input signal proportional to the system supply voltage for adjusting the current flowing in the field windings of an electrical alternator which controls the output power thereof, comprising:

• output driving means coupled to the field windings of the alternator for controlling the current flowing therein;
• oscillating means for providing first and second output signals;
• regulating means having an input responsive to the input signal and an output coupled to said output driving means for providing a pulse train thereat which has duty cycle inversely proportional to the amplitude of the input signal;
• capacitive means for developing a voltage thereacross;
• means coupled to said output of said regulating means for converting said duty cycle of said pulse train to a charging signal for developing said voltage across said capacitive means proportional to said duty cycle of said pulse train;
• first comparing means for asserting an output signal when said first output signal of said oscillating means exceeds said voltage across said capacitive means;
• and
• first latching means having first and second inputs and an output, said first latching means being responsive to said output signal of said first comparing means being applied to said first input for providing a low output signal, said first latching means also being responsive to said second output signal of said oscillating means applied to said second input for providing a high output signal, said output being coupled to said output of said driving means for disabling said pulse train in response to said output signal of said first comparing means.

A method of inserting a time delay in a regulator which is responsive to the system supply voltage for providing a pulse width modulation output signal for controlling the average field current flowing in a alternator, comprising the steps of:

• generating a pulse train having a duty cycle inversely proportional to the magnitude of the system supply voltage;
• developing first and second oscillating signals each having a period less than the time constant of the current flowing in the alternator;
• converting said duty cycle of said pulse train to a charging signal;
• using said charging signal to develop a voltage across a capacitor proportional to the duty cycle of pulse train;
• comparing said voltage across said capacitor to said first oscillating signal;
• disabling the pulse width modulated output signal when said first oscillating signal exceeds said voltage across said capacitor;
• using said second oscillating signal to reset said pulse width modulated output signal once each oscillating cycle;
• and
• increasing said voltage across said capacitor by a predetermined amount during each oscillator cycle as said duty cycle of said pulse train increases in response to an increase in the load applied to the alternator.