Abstract: An oscillating circuit provides first and second reference signals having a phase difference of 90.degree. with respect to each other. The oscillating circuit includes an oscillator providing the first reference signal at an output thereof, a voltage-to-current converting circuit, which may incorporate a common-base transistor, and a capacitor connected between the output of the oscillator and an input of the converting circuit. The output of the converting circuit then provides the second reference signal which differs in phase by 90.degree. from the first reference signal. The oscillator may include differentially connected transistors and an LC resonant circuit.

Abstract: An oscillation generator providing a succession of oscillations repetitively and progressively varying in amplitude includes a feedback oscillator arranged to receive its operating voltage from a capacitor that is progressively charged from a periodically fluctuating voltage source by way of an SCR and a timing circuit arranged to progressively vary the timing during the fluctuation period of the source of firing signals applied to the SCR. The timing circuit includes a firing capacitor charged from a unidirectional source and semiconductor switches arranged, when the potential on the firing capacitor attains a predetermined level, to discharge the capacitor into the trigger electrode of the SCR. The time required for the potential on the firing capacitor to reach the predetermined level is varied by a saw-tooth generator that controls the charging potential for the capacitor.

Abstract: The specification discloses a regulated temperature compensated current source in combination with a self resonant oscillator. The current source receives an unregulated DC voltage and compensates the DC voltage with a negative current coefficient. A current source circuit receives the compensated DC voltage in order to generate a regulated current. The current source circuitry has a positive temperature coefficient to thereby provide temperature compensation to the generated current. The oscillator includes a resonant transformer connected at the ends thereof to first and second transistors. A pair of voltage detectors are also connected across the ends of the transformer for receiving drive current and for rendering alternate ones of the transistors conductive in dependence upon which end of the transformer is at the highest potential.

Abstract: This invention provides an inverter circuit in which an output transformer has a tapped primary winding, one portion of which provides a collector load for a first transistor and the other portion of which provides a collector load for a second transistor, with a saturating transformer arranged to provide oscillatory positive feedback from the collectors to the bases of the transistors. The feedback paths from the saturating transformer to the bases of the transistors each includes the base/emitter path of a respective additional transistor and current is supplied to the collectors of the additional transistors in order to maintain operation during saturation.

Abstract: A vehicular battery charging system particularly adapted for railroad cars such as cabooses, in which an axle drive/hydraulic pump unit is coupled to the end of an axle via a flexible coupling and right angle gear drive. The hydraulic pump provides hydraulic pressure to a hydraulic motor/alternator unit. The a.c. output from the alternator is rectified and the resulting d.c. is employed to charge the batteries at a voltage which is very accurately controlled by a voltage regulator. The regulator comprises a switching circuit controlling the excitation of the field or rotor winding of the alternator by the rectified alternator output, in response to a repetitive pulse signal from a free-running multi-vibrator.

Abstract: An improved integrated circuit oscillator adapted for crystal-controlled applications eliminates the need for capacitors and duty cycle control circuitry by using a cascaded pair of push-pull complementary transistor amplifier stages, a clipping-type automatic amplitude control circuit, and a resonant feed back path between the two amplifier stages. In an illustrative embodiment, floating bias voltages are established by a chain of diodes, with several bias currents set with respect to the chain current by emitter area relationships. Square-wave output is provided by a flip-flop connected to push-up and pull-down output circuits.

Abstract: In an induction energy transfer device comprising a static power conversion circuit for producing an alternating magnetic field of ultrasonic frequency of the type wherein the static power conversion circuit includes a parallel resonant circuit which comprises a coil which also couples power across an air gap, an improvement in efficiency and power transfer is obtained by including at least two such parallel resonant circuits in the power conversion circuit, one of which resonant circuits is tuned to the third harmonic of said fundamental frequency.

Abstract: A frequency modulated push-pull oscillator in which the non-linear characteristic of varactors producing frequency modulation is compensated for by an opposite non-linear characteristic of a field effect transistor (FET) providing modulating bias to the varactors.