Abstract: The load drive apparatus has a driver unit and a control unit. The driver unit includes a control section modulating, in accordance with a PWM signal supplied from the control unit, a drive signal to be applied to a load apparatus between a high level and a low level, and a short circuit detecting section detecting, on the basis of a signal level of the PWM signal and a signal level of the modulated drive signal, short circuit on a path through which the modulated drive signal is applied to the load apparatus. The control unit includes a function of fixing a duty ratio of the PWM signal upon occurrence of short circuit to determine to which of a high-level side and a low-level side the path is short-circuited.

Abstract: A control apparatus controlling the operation of pulse width modulator for an electric clutch or electric motor in portable spray painting equipment having a pressure transducer for sensing the pressure, a manually adjustable pressure reference, a comparator type error detector, and a pressure deadband control for inserting a deadband in a pressure control loop with the deadband varying as the pressure reference varies. A fixed deadband is provided below a predetermined low pressure setting to avoid excessive cycling of the control apparatus during low pressure operation. The pulse width modulator control circuit includes compensation for improving input power factor. The clutch control includes an active alternative load circuit switched in when the alternator output voltage is above a predetermined value.

Abstract: A control apparatus incorporated in a charging generator for controlling interruption of an exciting current supplied to a field winding of the charging generator comprises a power transistor for intermittently interrupting the exciting current, a voltage detecting circuit for controlling on-off of the power transistor depending on the voltage generated by the charging generator, a current detecting circuit for detecting an initial exciting current supplied to the field winding until the charging generator generates an output voltage high enough for starting its charging operation, and a circuit for turning off the power transistor as soon as the value of the current detected by the current detecting circuit exceeds a predetermined setting.

Abstract: Apparatus for use in an electrical power generating system including a generator for supplying an A.C. output voltage to a load on a set of lines and a circuit responsive to the A.C. output voltage for producing a regulating voltage, the generator having a winding the D.C. energization of which controls the A.C. output voltage. The apparatus controls the energization of the winding and includes a switching circuit adapted to be connected across a resistance and which when rendered conductive bypasses the resistance to couple the voltage regulating circuit to the winding with negligible loss of energy. The switching circuit is combined with a circuit that produces a signal when an increase in the A.C. output voltage exceeding a preselected parameter occurs, and with another circuit that renders the switching circuit nonconductive in response to the signal thereby causing the resistance to consume energy from the winding. Methods of operation of the apparatus are also described.

Abstract: A control unit is disclosed for controlling the driving torque of a generator driven by an engine in accordance with the number of cylinders to be operated, thereby to achieve stabilized operation. A voltage regulator is provided for varying the field current through the field coil of the generator so as to regulate the output of the generator. A circuit component including a pair of NC contacts in parallel with a resistor is connected in series between the field coil of the generator and a power source. Depending on the number of cylinders to be operated, the NC contacts are either closed to provide a low resistance path for current to the field coil or are opened to provide a high resistance path through the resistor.