Abstract: A system for aircraft gunnery training and accuracy evaluation wherein a head-up display unit employs a cathode ray tube for projecting simulated bullets on a pilot's sighting panel. The simulated bullets each comprise a pair of bullet trajectory indicia simulating the firing of the guns of the aircraft at an actual target. The indicia in a pair of bullet trajectory indicia are equidistantly spaced from the simulated trajectory path by an amount related to a selected dimension of the target. Each pair of bullet trajectory indicia are initially displayed to reflect the physical conditions of the aircraft at the time of firing, including the rates of aircraft roll, pitch and yaw, the aircraft lift acceleration, true aircraft airspeed, gun angle of attack, and relative air density. As the bullet trajectory indicia traverse the simulated trajectory path, the separation between the indicia comprising a pair of indicia is decreased to simulate increasing distance from the firing aircraft.

Abstract: A frequency control utilizing a reference oscillator and a signal controlled oscillator is disclosed. The frequency control maintains the frequency of an output signal at the same frequency as the reference oscillator if there is no signal present at a frequency control input. A signal at the frequency control input causes the frequency of the output signal to be varied accordingly. The frequency control contains a feedback loop which compares the output of the signal controlled oscillator with the fixed frequency of the output of the reference frequency oscillator. The frequency control of the present invention has particular applicability as a frequency control for parallel-connected AC systems.

Abstract: A phase lock loop commutation position control and method for a drive system for a DC field motor having a rotor and a plurality of stator windings is disclosed. Electric power is supplied to the stator windings in accordance with gating signals. The gating signals are generated in accordance with timing signals, which are provided in response to a clocking signal. A position signal is furnished as a function of the position of the rotor with respect to a preselected stator position. An error signal is generated proportionally to the phase difference between a preselected timing signal and the position signal. The clocking signal is produced as a function of the error signal. The invention also can include a shift signal produced as a function of the rotation of the rotor. The shift signal is added to the error signal effectively to cause the preselected timing signal to be advanced with respect to the position signal.

Abstract: Shunt regulation for a high-voltage circuit including a ferroresonant transformer has control circuitry associated with a low-voltage control winding on the transformer, the control winding being magnetically coupled with the high-voltage secondary winding thereof. The control circuitry includes a zener diode for clamping peak voltages on the control winding and a sub-circuit including a voltage-divider and a capacitor. An averaged voltage from the divider/capacitor is compared with a reference by a comparator. Both the comparator and the zener diode serve to turn on a transistor connected across the control winding output, thereby allowing current to flow through the control winding, dropping the output voltage thereof. Regulation of the output voltage on the transformer high-voltage secondary results.

Abstract: A circuit means by which a high voltage, complex load may be precisely sensed and controlled. With high voltage AC loads, the effect of unavoidable stray capacitances is to render extremely difficult to measure and/or control that portion of total current which contributes actual power; that is, the resistive portion. Herein described is a circuit for rejecting all capacitive currents while measuring only the true resistive portion and deriving from the signal a filtered (averaged) voltage suitable for regulation and/or control. The circuit samples the total current only during the time when there is no capacitive current flowing. This sample is then compared with a reference, the difference amplified, and then averaged over many samples to derive a precise control signal.

Abstract: A transformer having a core and coil assembly which includes a pair of cores disposed side by side, the core members being of the squared "O" type formed of a plurality of nested, generally rectangular laminations. A space is provided between a pair of adjacent laminations in corresponding locations in each core, and a coil surrounds the adjacent sides of the respective cores through the central openings of the cores. Also included is a terminal board support having a pair of tabs to be inserted in the spaces between the adjacent laminations, the tabs being provided with holes having extruded edges for frictional engagement with the core laminations. The core and coil assembly is placed upon a flat base member and a U-shaped band is placed so as generally to encompass the top and two sides of the core and coil structure to make contact with a part of up-turned flanges of the base member.

Abstract: An electrical fuseholder for receiving an elongated, cylindrical fuse is provided with a pair of sheet-metal terminals which serve as means for connection into a circuit to be protected, as well as mechanical mounting means. The terminals are secured respectively between a pair of U-shaped fuseholder clips and an electrically insulating base and are provided with flanges for prevention of rotation of the respective terminals relative to the insulating base and of the U-shaped clips relative to the respective terminals.

Abstract: A circuit including a switching regulator and a pair of pulse transformers for selectively starting and operating a pair of arc discharge lamps. The lamps are arranged to be connected in parallel across the regulator output, and in order to operate one lamp at a time, the circuit is provided with low-voltage switching means for selecting the lamp to be started and operated. This switching means, in the form of a ganged switch, includes a switch portion for completing an enable circuit from the regulator controller for enabling the regulator and a pulse generator, and a second switch portion for steering pulses from the generator to the pulse transformer associated with the lamp selected for operation.

Abstract: An electromagnetic motor is provided with a samarium cobalt permanent magnet comprising a plurality of radially abutting segments. A combination of linear and non-linear springs with a force gradient larger than the magnetic force gradient facilitate motor operation in proportion to currents in electrical coils positioned on each side of the permanent magnet. Servoamplifiers independently control the current in each electrical coil in response to an input command signal, a motor position feedback signal and an actuator position feedback signal. A failure detection circuit detects coil failure by comparing current in each coil on one side of the magnet with the current in a corresponding coil on the opposite side of the permanent magnet. The circuit produces output signals to disconnect a defective coil and initiate an alarm. The circuit also detects power supply and motor position transducer failures by comparing their respective output voltage signals against predetermined reference voltages.

Abstract: A cooking cycle timer includes two timing circuits, each incorporating an oscillator and a counter. The first timing circuit times the first portion of a cooking cycle, and the second timing circuit times a predetermined second portion. At the end of the first portion, a visible indicator is turned on to indicate that the predetermined second portion of time remains in the cooking cycle. At the end of the second portion, and thereby the end of the cooking cycle, the visible indicator and an audible indicator are operated in pulsed fashion through the operation of a third oscillator. Visible indication is also provided during the first portion of the cooking cycle to show that the timing circuit is active.

Abstract: A battery charging circuit includes a ferroresonant transformer having a rectified output for providing a constant output voltage to be supplied to a battery to be charged. Battery temperature is sensed providing an input to a control circuit which operates a shunt regulator associated with the ferroresonant transformer to provide battery charge voltage as a function of battery temperature. In response to a high battery temperature the controller functions to lower the output voltage to the battery, and in response to a low battery temperature, operates to provide a higher output voltage, with suitable control for any battery temperature between minus 10.degree. and plus 150.degree. Fahrenheit. As the battery approaches full charge and battery acceptance current falls below a predetermined level, a charge cycle termination control allows charging to continue for a period preset by the operator, at the end of which period, line voltage is removed from the charger thereby terminating the charge cycle.

Abstract: A cooking appliance, such as a deep fat fryer, includes programmable control system which monitors the operation of the cooking appliance and enables appropriate actions at proper times. The system includes a microcomputer which implements various timing and control functions. Control switches select operational states of the appliance. A diode matrix allows selection of input data. A multiplex circuit interconnects input signals to the microcomputer, a monitor circuit turns off the appliance if multiplexing stops. A temperature control circuit generates a signal responsive to the cooking fluid temperature and compares it with various reference signals under control of the microcomputer. A cooking control circuit generates a voltage proportional to the cooking fluid temperature, modifies it according to the desired doneness of the food being cooked, and converts it to a current which charges the capacitor in an oscillator.

Abstract: A circuit arrangement for starting a linear metal halide arc discharge lamp while in a transistor switching bridge inverter circuit in the running inverter mode. A high voltage pulse generator is connected to a trigger electrode which is arranged for capacitive coupling to the lamp to supply pulsed high voltage thereto. A synchronizing circuit serves to synchronize application of the high voltage pulse to the trigger electrode with the turn-on of either polarity of the switching inverter. An inhibit circuit prevents high voltage pulsing of the trigger electrode after lamp ionization when the lamp is in a normal operational mode.