Alternator voltage regulator

A voltage regulator circuit for an alternator having a rotor which rotates relative to a stator for generating an alternator voltage output and a field winding for increasing the alternator voltage output when a field current flows therethrough, said voltage regulator circuit comprising:

• a speed sensing means including an operational amplifier having a first input operatively connected with an isolated speed dependent output of said alternator and having a second input operatively connected with the alternator voltage output, said operational amplifier producing a high output when the magnitude of the signal received on its first input exceeds the amplitude of the signal received on its second input and a low output when the magnitude received on its second input exceeds the magnitude of the signal received on its first input, said high output comprising a reference signal;
• first comparator means for producing an enable signal in response to the alternator output voltage reaching a predetermined relationship with said reference signal, said first comparator means being operatively connected with said speed sensing means and with said alternator;
• and,
• switching means for switching the field current to said field winding in response to said enable signal, said switching means being operatively connected with said first comparator means.

A voltage regulator circuit for an alternator having a rotor which rotates relative to a stator for generating an alternator voltage output and a field winding for increasing the alternator voltage output when a field current flows therethrough, said voltage regulator circuit comprising;

• speed sensing means for producing a reference signal in response to the rotation of the rotor relative to the stator exceeding a predetermined speed;
• an operational amplifier having a first input operatively connected with said speed sensing means, a second input operatively connected with the alternator voltage output and an output, said operational amplifier assuming a high state when the amplitude of the signal received on the first input exceeds the amplitude of the signal received on the second input and assuming low state when the amplitude of the signal received on the second input exceeds the amplitude of the signal received on the first input, in said high state an enable signal is produced on the operational amplifier output;
• a feedback loop connected between the operational amplifier output and the operational amplifier first input for reducing the amplitude of the reference signal received on the first input in response to said enable signal;
• and,
• switching means for switching the field current to said field winding in response to said enable signal, said switching means being operatively connected with said operational amplifier output.

A voltage regulator circuit for a three phase alternator having a rotor which rotates relative to a plurality of stator coils for generating a potential across an alternator output, having at least one field winding which increases said potential when a field current flows therethrough, being adapted for charging a rechargable battery connected across the alternator output, and having a speed dependent output which carries a potential that varies substantially with the speed of the rotation of the rotor relative to the stator, said voltage regulator circuit comprising:

• a first operational amplifier having a first input operatively connected with the speed dependent output and having a second input operatively connected with the alternator output, said first operational amplifier producing a high output signal when a predetermined relationship exists between the amplitude of the signals received on its first and second inputs;
• a second operational amplifier having a first input operatively connected with the output of said first operational amplifier and having a second input operatively connected with the alternator output, said second operational amplifier producing a high output signal in response to a predetermined relationship between the amplitude of the signals received on its first and second inputs;
• and,
• a power transistor connected in series with the alternator field winding, the base of the power transistor being operatively connected with the output of said second operational amplifier such that the high output signal of the second operational amplifier renders said power transistor fully conductive.

A battery recharging circuit comprising:

• an alternator having three stator windings connected in a Y configuration, a speed dependent output operatively connected with a common connection of the three stator coils, an alternator output operatively connected with the stator coils, and a field winding for increasing the potential at the alternator output when a field current flows therethrough;
• a battery which is operatively connected with said alternator output;
• and
• a voltage regulator circuit having (i) a first comparator means for producing a reference signal when some predetermined relationship exists between the amplitude of signals received on its first and second

A voltage regulator circuit for an alternator which includes a rotor that rotates relative to a stator for generating an alternator output voltage on an alternator voltage output and a field winding for increasing the alternator output voltage when a field current flows therethrough, said voltage regulator circuit comprising:

• speed sensing means for producing a fixed amplitude DC reference signal in response to the rotation of the rotor relative to the stator exceeding a predetermined angular velocity and a low signal below the predetermined angular velocity;
• a bistable solid state circuit means selectively assuming a first state in which the bistable circuit means produces a high output signal on a bistable circuit means output such that the bistable circuit means functions as a current source and second state in which the bistable circuit means produces a substantially fixed amplitude low output signal on the bistable circuit output such that the bistable circuit means functions as a current sink, the bistable circuit means includes a first input operatively connected with said speed sensing means and a second input operatively connected with the alternator voltage output, said bistable circuit means assuming the first state in response to the fixed DC reference signal exceeding a fixed function of the alternator output voltage and assuming the second state in response to the fixed function of the alternator output voltage exceeding the signal from the speed sensing means;
• and,
• switching means for switching the field current to said field winding in response to said bistable circuit means high signal, said switching means being operatively connected with said bistable circuit means.