Showing papers on "Boost converter published in 1974"

DC component suppression in zero CF IF systems

Abstract: Disclosed is a zero center frequency IF system having an all digital complex multiplier in which DC components in the IF signals are removed from an A/D converter output. Any DC level which reaches the input of the A/D converter or any misalignment in the A/D converter causes the digital outputs to contain unequal numbers of positive and negative words. The sign bit of the digital output is coupled to the input of an integrator which generates a DC output proportional to the DC offset in the A/D converter output. The integrator output is substracted from the IF signal coupled to the input of the A/D converter and cancels any DC components present.

Temperature compensated current sensing circuit for a power supply

Abstract: A converter power supply is provided with a novel current regulating circuit. A magnetoresistive element is disposed in flux coupling proximity to the output inductor of a power supply for providing a control signal corresponding to the output current thereof. The element is mounted in the air gap of the split-loop core of the inductor.

Variable frequency power converter for ac motor drive

Abstract: In a variable frequency power converter of a current type for driving an AC motor including a rectifier, an inverter, and a smoothing reactor disposed on a DC transmission line between the rectifier and the inverter, there are provided a series circuit having a switching circuit and a smoothing capacitor on the DC input side of the inverter and a feedback circuit having controlled rectifier elements and commutation reactors for feeding back the reactive power of the AC motor. The power converter operates as a current type converter until the output frequency of the converter reaches a predetermined value under the condition that the switching circuit and the controlled rectifier elements are non-conductive, and operates as a voltage type converter when the output frequency has reached the predetermined value under the condition that the switching circuit and the controlled rectifier elements are conductive.

Regulated AC to DC converter having a controllable rectifier assembly

Abstract: An output-regulated AC to DC converter has a rectifying stage including a plurality of thyristors each shunted by a diode of opposite polarity. The excitation of a coil disposed between an input transformer of the converter and the rectifying stage is controlled by selectively varying the thyristor conduction patterns so that the output DC voltage may be added to or subtracted from the transformer output voltage, depending on the sense of deviation of the actual coil current from a reference coil current. Such reference current, in turn, is derived as a sinusoidal quantity whose phase is coincident with that of the AC input voltage to the converter and whose amplitude is proportional to the difference between the DC output voltage of the converter and a desired value.

A.C. - D.C. power converter for D.C. load

Abstract: A power converter which can operate with both a D.C. power source and an A.C. power source for supplying electric power to a D.C. load such as a D.C. motor. The power converter comprises thyristors, a diode, a reactor and a capacitor. A plurality of series circuits each including two series-connected thyristors are connected in parallel to provide A.C. terminals at the series connection points of the thyristors and to provide D.C. terminals at the parallel connection points of the series circuits. The diode is interposed between the parallel-connected series circuits of the thyristors, and the reactor and the capacitor are connected in series to form a series circuit which is connected in parallel with the series circuits of the thyristors. The power converter is connected at the D.C. terminals between the power source and the load to function as a chopper when the power source supplies D.C. power to the load. On the other hand, when the power source supplies A.C. power to the load, the power converter is connected at the A.C. terminals to the power source and at the D.C. terminals to the load to function as a converter or inverter. The desired function of the power converter is obtained by controlling the gate signal applied to the gate of each of the thyristors.

Variable duty cycle balanced DC/DC power converter

Abstract: A balanced DC/DC power converter employs a transformer in combination with a simplified arrangement for generating variable duty cycle pulses to deliver a load voltage which may be greater or less than the power supply voltage.

Direct-direct symmetrical converter power pack

Abstract: The converter comprises an autotransformer, four taps of which are respectively connected to one electrode of four transistors. When a direct voltage is applied to one or the other input of the converter, these transistors are alternately, by pairs, blocked and saturated, changing the direction of the current flowing in t

Boost regulator with high voltage protection

Abstract: A bosted B+ regulator in a horizontal deflection system comprises a controlled rectifier coupled to a winding in the deflection system for rectifying voltage generated therein and adding it to the line-rectified voltage for providing a constant boost voltage for operation of the deflection system in the presence of line voltage fluctuations. A zener diode is coupled between the rectified line voltage and the rectified boost voltage and to a control electrode of a switching device such as an SCR. Normal deflection system starting current is coupled through a junction of the SCR and through the zener diode in the forward direction. When the boost voltage exceeds a predetermined level, the zener diode breaks down, causing the SCR to conduct which in turn provides a short circuit across the rectifier and its associated winding for disabling operation of the deflection system.

Input signal powered converter

Abstract: Input signal powered converter apparatus comprises A. A SIGNAL SOURCE TO PRODUCE AN ANALOG OUTPUT CURRENT, B. CONVERTER MEANS RESPONSIVE TO THE SOURCE OUTPUT CURRENT TO PRODUCE AN OSCILLATORY OUTPUT SIGNAL WHICH VARIES AS A LINEAR FUNCTION OF THE SOURCE OUTPUT CURRENT, C. A DETECTOR RESPONSIVE TO SAID OSCILLATORY OUTPUT SIGNAL, AND D. CIRCUITRY COUPLED BETWEEN THE SOURCE OUTPUT AND THE CONVERTER MEANS TO ELECTRICALLY ENERGIZE THE CONVERTER MEANS IN RESPONSE TO CURRENT SUPPLIED BY THE SOURCE OUTPUT.

Negative DC to positive DC converter

Abstract: A direct current power supply is capable of delivering up to 1 ampere at 60 to 80% power efficiency from a storage battery source, providing a positive DC power output free from inductor-generated type switching transients. The converter embodies a regenerative switching mode means which alternately drives two sets of paired power transistors, turning on each one pair of power transistors for one-half cycle. Each one of the power transistor pair alternately transfers electron charges to a first one of two switch-coupled capacitors, thence to the second one of the two capacitors, and then to a positive voltage terminal. RC clipping circuitry is coupled to each one of the pair of power transistors providing faster resetting times for the power transistors, increasing the converter power efficiency by decreasing storage-time delay. By decreasing power transistor direct shorting time during power transistor switching between transistor pairs, power loss is decreased.

Frequency converter for power supply to variable speed synchronous machines

Abstract: Frequency converter having the advantage of a better performance, reduced voltage stresses on the thyristors and lower rate of harmonics in the supply line. It comprises a transformer having two separate secondary windings which supply power to the converter through a smoothing d.c. reactor connected at each end to three thyristors or diodes connected respectively to said secondary windings. Applicable for power supply to variable speed synchronous machines.

Voltage monitor and control circuit

Abstract: A circuit for the monitoring and control of a DC to DC regulated power supply furnishing regulated voltage to a load. The output of the power converter is ultimately used to control a pair of shunting transistors which control the switching transistors in the power converter.

Automatic turn-on circuit for a DC to DC down converter

Abstract: A DC to DC down converter having a semiconductor switch connected between the input and output terminals thereof, which switch is controlled by a variable pulse generator and an automatic turn-on circuit including a voltage divider connected between the input and output terminals of said converter, switching means operable in response to a voltage across said voltage divider and controlling the application of power to the variable pulse generator, and a diode connected between the semiconductor switch and the junction of the voltage divider and output terminal to allow the converter to shutdown when the load is removed from the output terminal.

A DC-DC Converter for Radiation Monitors

Abstract: To provide supply voltages for a detector and electronic circuits is a problem which frequently arises in designing a radiation monitor. With portable assemblies, which use primary or secondary batteries, this problem must bo solved by using DC-DC converters. In general, for each supply voltage a separate DC-DC converter may be used, but in some cases a single converter can produce two or more output voltages. The DC-DC converter should have high efficiency and stable output voltage. The two principal reasons for which the output voltage might change its value are the changes of the batteries voltage and of the converter load. The converter which will be described here can stand very large variation of the batteries voltage and produces two output voltages, one for electronic circuits of the monitor, and the other for its GM counter.