Showing papers on "Buck converter published in 1975"

Pulse width modulated voltage regulator-converter/power converter having push-push regulator-converter means

Abstract: Disclosed herein is an improved pulse width modulated (PWM) voltage regulator-converter system which can function, alone, as a switched voltage regulator system or in combination with a switched power converter, synchronized therewith to form an improved voltage regulator-converter/power converter system. In the pulse width modulated voltage regulator-converter embodiment of the invention, secondary windings of a "current mode" regulator-converter interstage transformer are coupled to regulator-converter power transistors in a push-push circuit configuration. Signals generated by a system clock means and an error signal, derived from the output of an averaging filter, drive a pulse width modulated control means connected to the primary windings of the regulator-converter interstage transformer to thereby increase the maximum regulated output voltage of the voltage regulator-converter system after conditioning in the averaging filter. In the pulse width modulated voltage regulator-converter/power converter embodiment of the invention, the aforementioned output voltage of the voltage regulator-converter system is coupled directly to a switched power converter connected in a push-pull circuit configuration. In turn, additional signals generated by the system clock means switch the power converter in synchronizm with the voltage regulator-converter system.

Converter circuit and method having fast responding current balance and limiting

Abstract: A regulated voltage converter utilizing an improved method of pulse width modulation is disclosed wherein acceptable current balance and limiting in the converter switching elements are speedily achieved within one half cycle of converter operation. Converter output current is monitored, shaped according to a non-linear transfer function, and integrated to form a voltage signal for comparison with a predetermined reference level. When the integrated signal exceeds the reference level, a control signal is generated to terminate the current pulse in the inverter section of the converter. The inherent balancing and limiting characteristics of this arrangement are easily extended to applications wherein multiple converter stages are paralleled to supply higher power to a common load.

Power supply for high power loads

Abstract: A power supply capable of transferring power at high current and voltage levels to a load which may be highly inductive. The power supply includes an inverter for receiving DC power and inverting it to an AC intermediate signal. The intermediate signal is rectified by a converter to provide a DC output voltage to a load. Commutation of the controlled rectifying devices within the inverter and converter are provided by capacitors connected across the output terminals of the inverter. The DC output voltage provided to the load is controlled by the frequency of the firing signals provided to the controlled rectifying devices within the inverter. A large energy storage inductor, which may be superconductive, is connected to the inverter and may be utilized to provided the pulses of power required by the load. A converter connected to an AC power system is provided to supply external power and to recharge the current flowing in the energy storage inductor. Power may be transferred reversibly, from the energy storage inductor to a load inductor and back again.

State variable stability analysis of multi-loop PWM controlled DC/DC regulators in light and heavy mode

Abstract: Stability analysis and transient response predictions of PWM controlled DC/DC regulators are now feasible in both continuous and discontinuous mode A linear equivalent continuous model of the power stage is firstly established for the boost and the buck converter by means of state variable representation for each of the elementary structure occuring within one sampling period. This equivalent model turns out to be of first order for the discontinuous mode and of 2nd order for the continuous mode. A general computer program has been implemented for the derivation of such a model and for the stability analysis and transient response of multiloop regulators. Special emphasis has been given to the boost converter in light conduction mode operation whether an AC feedback loop is included or not. The existence of the non-minimum phase effect associated with such a regulator for a heavy operation mode is shown to be dependent of the sampling frequency.

High efficiency power supply having a reactive buck automatic d.c. voltage regulator

Abstract: D.C. power supply having a reactive buck automatic D.C. voltage regulator which directly controls the rectified D.C. output of a loosely coupled transformer thereby providing load regulation from an unregulated alternating current source. The load current passes through the secondary winding of an auxiliary buck transformer and is stepped down to a much lower value in the primary winding of the auxiliary buck transformer. The primary winding of the auxiliary buck transformer is coupled to an isolated winding on the core of a ferroresonant C.V.T. transformer which receives the unregulated alternating current input signal, and the coupling between the isolated winding and the primary winding of the buck transformer effects a bilateral energy transfer between the two transformers which effects a real time reactive compensation which regulates the D.C. output of the power supply for changes in the input voltage and in the load while conserving the energy which would normally be wasted in achieving regulation by transferring it back to the resonant circuit via the bilateral energy transfer between the two transformers. The control system is set up so that the auxiliary buck transformer is normally bucking under all line and load conditions when the frequency is precisely at the resonant frequency of the saturable inductor and capacitor. A frequency shift either above or below resonance simply changes the amount of bucking that takes place in a complimentary manner. It should be noted that little power is consumed during the buck process as the power is returned from the auxiliary buck transformer to the loosely coupled ferroresonant transformer. The operating point of a negative feedback system which determines the point about which the bilateral energy transfer occurs, may be fine-tuned by an error-sensing feedback circuit for altering the voltage level which the coupling network operates to hold constant by controlling the bilateral energy transfer. A capacitor is provided across the primary of the auxiliary buck transformer to reflect capacitance into the secondary winding during conditions of little or no bucking action in order to enhance the stability of the regulator.

Improved single-ended regulated dc/dc converter circuit

Abstract: Three basic single-ended converter configurations are compared analytically and experimentally. The ringing-coil converter is recommended for low-power, high voltage, single output applications where low cost is essential. The single-ended half-wave transformer-coupled converter is recommended where the maximum output power is being squeezed for a given switching transistor power handling capability. The single-ended full-wave converter is recommended for applications with tight regulation, size, ripple and trouble voltage requirements.

A New Voltage to Frequency Converter

Abstract: The technique for improving the linearity between the input voltage and the frequency of oscillation is described. This improvement is accomplished by adding a control circuit to Concentional voltage-to-frequency converters. From the experimental results, the linearity of this converter was about 0.15 percent at the frequency of 1 MHz.