Abstract: A corona discharge monitor system for a dynamoelectric machine, particularly for large salient pole generators, has an antenna mounted on a rotor pole. The antenna sweeps over the stator slots and picks up radio frequency signals produced by corona activity occurring in the structure of the stator bars. A rotary coupler, having a rotating portion fixed to the shaft of the machine and a fixed portion adjacent to the rotating portion, couples the signal to a signal conditioner. A trigger signal synchronized with the rotor rotation and with a known reference to antenna position and derived from the power system line frequency, is used as one input to a storage device such as a variable persistence oscilloscope. A first output of the signal conditioner represents the peak amplitude of the corona discharge and a second output represents the number of corona occurrences and these are applied to the storage device.

Abstract: A method is provided for testing induction motors, particularly single-phase fractional horsepower motors, which enables routine testing of all motors in production for both starting and running torque and other desired characteristics. The method consists essentially of applying power to the motor for a very short period of time, such as three or four cycles of the supply voltage, then interrupting the power supply and immediately measuring the instantaneous speed by observing the induced voltage from the deenergized motor terminals. The torque then is verified from the change in speed over this short period. Both starting and running torques can be tested very quickly in this manner by means of solid-state control and computing devices, without connecting anything to the motor other than the power leads. Other desired characteristics of the motor can also be readily determined.

Abstract: An automobile alternator test apparatus tests for the presence of a failed diode by detecting a frequency component (a subharmonic component) in the alternator output ripple voltage produced by the failed diode. The subharmonic frequency component is detected by a tracking filter that is slaved to the subharmonic frequency of the ripple frequency voltage produced by the failed diode. The output signal of the slaved filter indicates the presence of the failed diode.

Abstract: A brushless excitation system for a synchronous dynamoelectric machine includes an alternating current exciter and a rotating rectifier assembly. In such a system, the alternating current exciter includes a salient pole stator field member and a polyphase armature rotor member. A sensing coil is disposed around at least one of the salient stator poles for developing an alternating electrical signal in response to changes in the magnetic flux wave linking the rotating armature member and the field coil of the salient stator pole member. Means connected to the sensing coil indicates variations in the alternating current signal which correspond with disturbances in the rotary electric circuit of the brushless exciter such as a line-to-line short circuit or a phase-to-phase short circuit in the armature winding, or shorted diodes or open fuses in the rotating rectifier assembly.

Abstract: Apparatus is described for monitoring arcing of brushes used in the transfer of current signals to and from the field of a generator. Electrical signals from the brushes, which are applied to the disclosed monitor for analysis, may include brush arcing signals to be monitored and in addition high-amplitude noise spikes in the same frequency band as the brush arcing signals, the noise spikes thus masking accurate detection of low level brush arcing by conventional devices. A two-stage clipping network is provided in the monitor to raise the brush arcing/noise ratio and thus mitigate the masking effect of the noise spikes without loss of a portion of sampling interval during which arcing may occur.

Abstract: Two monitor circuits, each having a light emitting diode, are connected to the inputs and outputs of an SCR current control circuit on a brushless a-c generator. The current control circuit and the attached monitoring circuits are mounted on a rotating shaft and information regarding the operation of the rotating current control circuit is obtained by observing the light patterns generated by the light emitting diodes.

Abstract: To permit selective control of the voltage level of the on-board vehicle network as a function of battery voltage or exciter field control voltage of an automotive alternator, and continued operation of the regulator in spite of malfunction of control connections to the regulator, a voltage divide which supplies a voltage regulating element is formed with an additional tap thereon, the additional tap being connected to a current supply which supplies current to the voltage regulator to modify the voltge level of the tap supplying the control potential to the voltage regulator. The voltge regulator includes a controlled semiconductor switch which is selectively energized in accordance with voltage level at the main tap of the voltage divider with respect to a reference level.

Abstract: A battery charging system includes an alternator, a main rectifier for charging the battery, and an auxiliary rectifier for supplying current to the alternator field winding under control of its voltage regulator 20. A first transistor switch is sensitive to under voltage to illuminate a first warning light and a second transistor switch is sensitive to over voltage to illuminate a second warning light. The two transistor switches are cross-connected so that failure of either light causes illumination of the other.

Abstract: A device for cutting out non-essential loads in a generator and battery-fed electric plant includes a voltage detecting unit connected across the terminals of the battery. The detecting unit may be a relay. Whenever the voltage at the terminals falls below a predetermined level, the detecting unit effects the disconnection of the non-essential loads from the terminals of the battery and generator.

Abstract: Test apparatus for electrically and mechanically testing the condition of alternators and starters used in automobiles, trucks and the like. The apparatus, in its preferred form, includes a pair of holding fixtures for securing a starter or alternator during test, the fixtures being configured to allow quick and easy insertion and removal of the unit. Electrical circuitry is connectable to the machine under test by quick connect leads, such as alligator clips, and includes interlocking switch means for allowing starters to be tested in one condition, and alternators in another condition. The electrical circuitry includes indicators for showing the electrical condition of the machine being tested. The apparatus is structured so that a device may be tested with a minimum of effort, allowing a typical test to be completed in less than a minute.

Abstract: The electric potential output from a battery and generator assembly is monitored by three electric indicator circuits, one of which includes a first indicator which is activated to indicate excessively low battery voltage when the normally deactivated transistor switch in said circuit is activated by deactivation of a bias control transistor resulting from deactivation of a zener diode when the output voltage from the assembly drops below a predetermined minimum; a second indicator circuit of which includes a second indicator which is activated to indicate excessively low generator charging voltage when the normally activated transistor switch in parallel with said second indicator is deactivated by deactivation of a zener diode when the output voltage from the generator drops below a predetermined minimum; and a third alarm circuit of which includes a third indicator which is activated to indicate excessively high generator charging voltage when the normally deactivated transistor switch in said third circui

Abstract: An analog simulator for simulating the mechanical resilience, mass and damping characteristics of a turbine-generator system. The aforementioned parameters are represented by inductance, capacitance and resistance in the simulating system. Electrical power at the output of a generator is sensed by a power transducer and is provided as input to the simulating system. The power is a measure of the torque on the shaft of the generator. The simulating system computes the torsional oscillations between rotating members of the turbine-generator system and provides electrical output signals which are related to the magnitudes and frequencies of the various computed torsional oscillations. The signals are provided to indicating means such as counters, strip recorders and oscillographs for recording the timing, magnitude, and frequency of the various torsional oscillations.

Abstract: A circuit for indicating faults in a storage battery charging system of the type including an alternator having a field winding and a rectifier circuit having respective battery charging and alternator field winding energizing output circuit terminals. A differential amplifier circuit, to which is applied normally equal reference sensing potentials which become unbalanced with alternator faults, produces a first fault indicating signal in the event of an alternator malfunction and a transistor having the control electrode connected to the rectifier circuit field winding energizing output circuit terminal produces a second fault indicating signal in the event of a failure of one of the diodes in the rectifier field winding energizing output circuit. These fault indicating signals trigger a transistor conductive to complete an energizing circuit for a fault indicating device.

Abstract: A generator voltage control apparatus includes a generator with a field coil and a battery which is charged by the output of the generator. A first transistor is provided for controlling the current passed through the field coil to maintain constant the voltage of the generator. A charge display lamp is connected in series to the first transistor. A second transistor is connected in parallel to the charge display lamp connected in series so that the second transistor is turned on by a voltage generated by the generator and is turned off by an overvoltage generated thereby.

Abstract: A fault indicator for a motor vehicle battery charging system of the type in which a diode-rectified alternating current generator supplies charging current to the vehicle battery and supplies other loads on the vehicle. The fault indicator is capable of detecting certain faults in the diode-rectified alternator and is capable of detecting certain faults in the generator voltage regulating system. The fault indicator system utilizes current difference operational amplifiers, one of which is connected to detect sharp negative voltage transitions caused by certain faults in the system. The fault indicator also has Zener diodes connected to provide an indication of faults that cause abnormally low or high voltage outputs of the diode-rectified alternator such as an open or shorted voltage regulator.

Abstract: A circuit for indicating faults in a storage battery charging system of the type including a voltage regulator controlled alternator field winding switching transistor and a rectifier circuit having a diode trio which supplies alternator field winding energizing current. A differential amplifier circuit, to which is applied normally equal reference and sensing potentials which become unbalanced with alternator faults, produces a first fault indicating signal in the event of an alternator malfunction and a transistor having the control electrode connected to the output of the field winding diode trio of the rectifier circuit produces a second fault indicating signal in the event of a failure of one of these diodes. These fault indicating signals trigger a transistor conductive to complete an energizing circuit for a fault indicating device. Additionally, an oscillator flashes the fault indicating device "on" and "off" in the event of a voltage regulator failure.

Abstract: An automatic generator and regulator tester and method thereof. With the apparatus and method described herein, various performance characteristics of the generator and regulator are determined for comparison, automatically and electronically, to known, standardized performance characteristics.

Abstract: To determine whether a motor is operative, where visual inspection of rotation is impossible or difficult, the motor is energized by connection to an AC source for a short interval to bring the motor to running speed. After lapse of the short interval the AC source is disconnected and the motor coasts to a stop. An AC detector determines that AC power has been terminated and closes a switch to connect a voltage detector to a memory. The voltage detector amplifies a residual EMF field generated while the motor is acting as a generator due to the presence of a residual magnetic field produced in the rotor during prior energization. The detected voltage sets the memory which energizes a motor rotation indicator.

Abstract: A road vehicle battery charging system includes an alternator and a rectifier assembly connected to apply d.c. to the battery. A further rectifier provides d.c. to a separate line from which current is drawn for the field coil under the control of a voltage regulator. The line is connected via a series circuit including a resistor and the vehicle ignition switch to one side of the battery, this resistor forming part of a switching circuit which operates a warning lamp whenever the voltage on the separate line is substantially less than voltage on said one side of the battery.

Abstract: Method and apparatus for testing DC motors, particularly permanent magnet DC motors, involving application of a constant voltage across the motor terminals and at an earlier or later time causing a constant current to flow through the motor. The constant voltage is applied across the motor terminals for a first predetermined time interval during a portion of which the current flow through the motor is compared with a reference level. If the motor current falls below the reference level during the portion of the first predetermined time interval the motor is defective. The constant current is caused to flow through the DC motor for a second predetermined time interval. If at the end of this second predetermined time interval, the DC motor terminal voltage is below a first level or above a second level, that is, the terminal voltage is outside an established voltage range, then the motor is found to be defective.

Abstract: A road vehicle battery charging system includes an alternator, and a rectifier connecting the alternator across a battery. A further rectifier provides an additional d.c. output for energising the field winding of the alternator and this additional output is connected to the appropriate battery terminal via an ignition switch. A voltage sensing circuit operates to illuminate a warning lamp should the voltage on the line exceed a predetermined level.

Abstract: In a voltage regulating system, a transistor switching circuit is connected to a voltage sensing circuit which detects a battery voltage and to a lamp. And at least when the voltage sensing circuit becomes disconnected from the battery, the transistor switching circuit is switched on to energize the lamp to inform a driver of the disconnection.