Abstract: A hand tool for inserting a contact or pin into electrical components which tool subsequently resets itself for inserting another contact. Such tool transfers manual mechanical energy to hydraulic energy thereby allowing for reducing the size of the tool.

Abstract: An output configuration for an electronic ballast system includes means for effecting independent selection of both pre- and post-ignition lamp filament voltages. The primary of a filament voltage control transformer is coupled to lamp filaments so as to induce a voltage in the transformer secondary windings in relation to the lamp filament current. The secondary windings are arranged so that the voltage induced therein adds to the voltage provided to the lamp filaments by filament drive windings on the ballast output transformer.

Abstract: A delayed starting circuit for an electronic ballast system that includes an inverter coupled to a secondary voltage source. The starting circuit includes a voltage divider having an input coupled to a charge storage capacitance in the voltage source and an output coupled through a semiconductor switching device to an input of the inverter. The switching device remains non-conductive until the capacitance has been substantially charged, thereby protecting the inverter from transients encountered as a surge of charge is delivered to the capacitance subsequent to the initial energization of the ballast circuit.

Abstract: An improved output configuration for a multiple-lamp electronic ballast system. The output includes a differential transformer having a primary adapted to be coupled in a first loop including a first filament filament drive winding and feedback winding and a secondary adapted to be coupled in a second loop that includes a second filament, filament drive winding and feedback winding.The improvement allows the entire ballast to be shut down when a lamp has been removed thereby avoiding aberrant oscillator operation under abnormal, yet predictable, lamp load conditions.

Abstract: An apparatus for testing signal indicating fuses. The apparatus comprises test positions for the acommodation of N fuses, each test position having a common, a normally open (NO), and a normally closed (NC) terminal. When the test positions are filled with N functional fuses, the fuses are, in effect, connected in series across a regulated current source. In the event that one of the fuses becomes open, the series circuit is momentarily broken, thereby triggering an associated SCR which in turn lights a lamp indicating which fuse has blown. Shortly afterwards the fuse flag will make contact with its alarm (NO) terminal, thereby reclosing the circuit. The apparatus may include or be coupled to a multichannel event timer in order to indicate the time, as measured from the start of the test, at which individual fuses failed.

Abstract: Apparatus for automatically measuring aperture size of a slotted apertured material includes a means for supporting and transporting a slotted apertured material having a plurality of slots with each having a longitudinal axis and a comparator mask overlaying the apertured material and having alternate light transparent and opaque sectors, a light source and a light detector disposed on opposite sides of the slotted apertured material and having a light beam directed therethrough wherein a rhombic-shaped aperture controls the size and shape of the light beam impinging the detector whereby advancement of the rhombic-shaped aperture along a diagonal axis provides a reduced rate of change in light transmitted by the slots and received by the light detector whereby fluctuations in light transmission are reduced for random variations in mask placement.

Abstract: A process for fabricating wire wafers from wire stock wherein the wire stock is fed against a wire stop member, surrounded by a support member having wire cut-off and back-up tools located integral to the support member with the wire cut-off and back-up tools activated to provide first and second wire wafers and de-activated to return the wire cut-off and back-up tools to a position for a succeeding cycle.

Abstract: An improved drive scheme for a pair of push-pull inverter transistors in an electronic ballast circuit. The inverter output is coupled through a series resonant circuit comprising a capacitor and the primary winding of an output transformer. The resonant circuit is coupled to the inverter output through an additional winding on the primary of an interstage so that a component of the loop current is fed back to the bases of the push-pull transistors, thereby compensating for phase errors in the drive signal applied at the inverter input.

Abstract: A dimmer circuit for an inverter-driven electronic ballast system. The ballast includes an output transformer having a primary winding coupled to the inverter output and a secondary winding adapted to be coupled to a lamp filament winding for supplying power to the filament. An interstage transformer has a primary winding adapted to be coupled to a lamp filament and a secondary winding coupled to an inverter input for applying a feedback signal derived from the filament current at that input. The dimmer circuit is in the form of a feedback loop that includes a winding on the primary of the output transformer, a winding on the primary of the interstage transformer, and a variable impedance coupling those windings. Varying the impedance necessarily varies the total feedback loop impedance and therefore the amount of feedback applied at the inverter output and, inversely, the power supplied to the lamp filament.

Abstract: In a CRT system having a cathode coupled to a source of first potential voltage and a control grid biased negatively with respect to the cathode, means coupled between a source of second potential voltage and control grid for superimposing negative-going transitions in the second potential voltage upon the control grid so as to suppress the appearance of spots upon the face of the CRT subsequent to the de-energization of that system.

Abstract: An interface circuit that couples the output of a differential AFC detector to a tuner and in so doing provides a single-ended control signal and a substantially constant reference signal. A bridging circuit combines the differential outputs to effect a substantially constant signal which is appropriately scaled by a referencing circuit so as to develop the reference voltage required. A dividing circuit coupled to one of the differential outputs develops an AFC control voltage having the range required to accommodate the tuner's AFC-responsive circuitry.

Abstract: A variable pulse rate tuning circuit for use with a channel-selecting system incorporating a single, shaft-encoded tuning knob. The circuit includes a single pulse circuit that generates an individual channel-stepping pulse in response to individual channel-changing pulses derived from the shaft-encoded tuning knob. In addition a pulse adding circuit sensitive to the repetition rate of the channel-changing pulses generates additional stepping pulses during conditions under which a substantial number of channels are sought to be bypassed. The pulse adding circuit includes an integrator to control the operation of a gated RC oscillator.

Abstract: A delay circuit for enhancing acquisition of a synthesizer PLL subsequent to change in the synthesizer's frequency of operation or a change in the source of tuning voltage applied to a voltage-controllable reference oscillator. A control circuit determines whether the reference oscillator operates in a crystal-controlled or in a voltage-controlled mode. The delay circuit includes a monostable having an output coupled to the control circuit and a trigger input coupled to both an ENTER CHANNEL indicator and a pulse generator. The monostable is triggered, thereby assuring temporary crystal-controlled operation of the reference oscillator, in response to an ENTER CHANNEL indicator or to an output from a pulse generator. The pulse generator is responsive to a change in the source of reference oscillator tuning control voltage from, for example, a manually variable fine tuning potentiometer to an AFC control circuit.

Abstract: An apparatus for coupling a source of signals to a receiver having a ground return electrically coupled to the AC line and for providing immunity from interfering ambient signals. The apparatus includes a coaxial transmission line surrounded at both ends by feedthrough capacitor coupling the outer conductor of the transmission line to the ground return of the signal source. A toroidal ferrite member also surrounds the transmission line between the feedthrough capacitors thereby reducing the current flowing in the outer conductor and the resulting direct pickup of ambient signals.

Abstract: In a VIR-responsive television receiver that also includes a manually-operated tint preference control, a circuit for indicating correct setting of that control. A comparator detects approximate equality between the VIR tint control voltage and the tint preference voltage. An LED, driven by the comparator, indicates the existence of this condition.

Abstract: A circuit for applying a fine tuning voltage to an oscillator operating within distinct ranges of frequency. The fine tuning voltage is tailored so that a substantially equal fine tuning range, for example, .+-.1.5 MHz, is achieved with respect to each of the ranges of frequency. The circuit includes a potentiometer that is connected between two voltage sources. The values of the voltage sources are appropriately varied in response bandswitch information. In a television receiver the values are varied in response to a signal indicating operation on a Low Band VHF, a High Band VHF, or a UHF channel.

Abstract: In a synthesizer system having a reference oscillator selectively operable in either a voltage-controlled or an injection-locked mode, a circuit for effecting the appropriate mode of operation. The circuit includes an analog gate coupled between the output of a crystal oscillator and the input of the reference oscillator. The analog gate is driven by a logic element responsive to a plurality of signals indicative of specific operating conditions. In particular, the circuit assures that the reference oscillator is coupled to the crystal oscillator, that is, the reference oscillator operates in the injection locked mode, while the synthesizer PLL achieves acquisition.

Abstract: A high input impedance, low output impedance, temperature-stable tuning voltage interface circuit with substantial ripple rejection and negligible DC offset. The circuit comprises two transistors of opposite conductivity types, the first being coupled through a resistor to a supply voltage and through a temperature-stabilizing, DC-offsetting diode to the output of the second transistor. The rejection of the ripple voltage superimposed on the supply voltage is determined by the ratio of the value of the resistor to the effective resistance of the diode.

Abstract: A chrominance take-off circuit effecting a transmission zero at a predetermined frequency approximately equal to one-half the chrominance subcarrier frequency. The circuit includes a capacitive branch coupled in series with a parallel RLC branch that is resonant at approximately the subcarrier frequency. At frequencies below the subcarrier frequency the RLC branch is equivalent to a series-connected resistance and inductance. At the predetermined frequency the magnitude of the impedance of the capacitive branch is substantially equal to the magnitude of the impedance of the equivalent inductance, resulting in maximum attenuation of luminance signals at the predetermined frequency.

Abstract: A circuit and method for effecting automatic brightness control for a television receiver CRT. The video signal is AC coupled to a signal input of a comparator. The comparator also has a reference input to which is applied a viewer-adjusted reference signal. A DC output voltage is developed in response to the difference in voltages present at the signal and reference inputs. The comparator is rendered sensitive, via a Video Blanking pulse to only the luminance component and a portion of the horizontal sync component of the video signal. The Video Blanking pulse can be synthesized by phase shifting and clipping the horizontal retrace pulses.