Rca Inc.

Sperry Corporation

Finis C Easter

Ramon H Aires

Charles A Clark, Jr

Kenneth Charles Adam

Donald P Clock

The input direct current used to build up the electromagnetic field surrounding the windings of a flyback transformer is converted by direct transformer action to current for replenishing charge in a first capacitor. Flyback current from the flyback transformer is used to replenish charge in a second capacitor. The sum of the voltages across the capacitors is supplied as converted energy to a load. In accordance with the invention, ripple in this output voltage is suppressed by proportioning the capacitances of the first and second capacitors to equal a nominal value of the ratio of the durations of the time intervals where direct transformer action obtains to the durations of the flyback intervals.

Switching DC-to-DC converters

In a switching dc-to-dc converter an output current substantially free of pulsations is provided by summing a flyback current and transformed current response to the current used to build up the electromagnetic field that stores the energy for flyback.

Switching dc-to-dc converters

A switching voltage regulator in which the input voltage to a switching dc-to-dc converter is boosted and the output voltage of the converter is indirectly regulated responsive to direct regulation of the boosted voltage.

Switching voltage regulators with output voltages indirectly regulated

A radio frequency transmitter-receiver alternately transmits signal pulses of frequency F.sub.1 and receives return echo signals of frequency F.sub.1. The transmitter signal of frequency F.sub.1 is generated by mixing signals of frequencies F.sub.2 and F.sub.3. A signal of frequency F.sub.3 is generated by mixing signals of frequencies F.sub.4 and F.sub.5. The return signal of frequency F.sub.1 is mixed with frequency F.sub.2 which is continuously generated by the transmitter to produce a signal of intermediate frequency F.sub.3. Frequency F.sub.5 and therefore frequencies F.sub.3 and F.sub.1 are only generated during signal transmission and therefore do not interfere with the return signal of frequency F.sub.1 and the produced intermediate frequency F.sub.3.

Pulsed radio frequency transmitting and receiving system

A voltage conversion circuit includes a transformer having a primary winding and a secondary winding with an output terminal. The primary winding is coupled in series with a switching circuit across a source of DC potential. The switching circuit periodically interrupts the DC potential to the primary winding and upon the interruption the primary winding undesirably produces a switching circuit damaging voltage spike. A voltage suppression circuit is responsive to the voltage polarity reversal in the transformer primary, which occurs when the input voltage is interrupted thereto for transferring the energy, which would otherwise produce the voltage spike, to the converter output terminal to add energy thereto. When the switching circuit is non-operational no voltage reversals are present in the transformer and no voltage is therefore passed to the output terminal.

Voltage supression circuit for a voltage converter circuit

A modulator for controlling the generation of radio frequency signals in a pulse radar system includes a timer for producing time separated turn-on and turn-off signals and a transistor switch responsive to those signals for controlling the timing of production of the radio frequency signals. In one aspect of the system a signal is applied to the timer to alter the time separation between the turn-on and turn-off signals.

Transistorized modulator for pulse radar

An astable multivibrator includes a first transistor a single capacitor arranged in a time constant circuit, coupled to the emitter of the transistor and a potential divider circuit coupled to the base of the transistor to apply a selectable portion of a bias supply thereto. A circuit including another transistor of polarity opposite to that of the first transistor responds to the first transistor in its conductive or non-conductive state for determining the portion of potential applied to the first transistor such as to drive the transistor into greater conduction when it is conducting and further from conduction when it is non-conducting. The threshold levels of the transistors track the voltage supply, which may be varied, such that the frequency and duty factor of the multivibrator are invariant with changes in voltage supply value.

Astable multivibrator circuit

A control transistor in the over-current protection circuitry of a voltage regulator is connected in a regenerative latch circuit with a complementary-conductivity auxiliary transistor, whereby conduction once initiated in said control transistor tends to be sustained. This avoids the tendency towards rapid oscillation between shut-down and power-up conditions in the over-current protection circuitry. The regenerative latch circuit loads the capacitor that supplies its sustaining current so heavily that the potential thereacross decays, the decay finally advancing to the point where regeneration halts. The resulting non-conduction of the control transistor permits the voltage regulator to attempt to resume the power-up condition. The present invention is an improvement in such a voltage regulator wherein circuitry is provided for rapidly recharging the capacitor for supplying sustaining current during this attempt. The recurrence of this cycle during short-circuit loading conditions leads to a relaxation oscillator mode of operation with the power-up duty cycle being sufficiently low that the components of the voltage regulator are kept from being damaged by overheating.

Over-current protection circuit for voltage regulator

A control transistor in the over-current protection circuitry of a voltage regulator is connected in a regenerative latch circuit with a complementary-conductivity auxiliary transistor, whereby conduction once initiated in said control transistor tends to be sustained. This avoids the tendency towards rapid oscillation between shut-down and power-up conditions in the over-current protection circuitry. The regenerative latch circuit loads the capacitor that supplies its sustaining current so heavily that the potential there-across decays, the decay finally advancing to the point where regeneration halts. The resulting non-conduction of the control transistor permits the voltage regulator to attempt to resume the power-up condition.

An analog-to-digital converter includes a common input amplifying device such as a transistor in differential amplifier relationship with each of a plurality of output amplifying devices, one for each voltage range converted to digital form. Separately controllable circuits are provided for: (A) setting a video display screen signal to the threshold of visibility, and (B) increasing the brightness of the screen to various levels above the threshold in accordance with digital signals from the analog-to-digital converter as modified by a brightness control.

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Canoga Park, CA, United States of America

Finis C Easter