Abstract: The present invention provides a DC-DC converter including a first series circuit connected to both ends of a first switch and formed of a winding of a first transformer, a first reactor, a first diode, and a smoothing capacitor, a second diode connected to a connection point of a primary winding of the first transformer, the winding of the first transformer and the first switch, and to one end of the smoothing capacitor, a second series circuit connected to both ends of a second switch and formed of a winding of a second transformer, a second reactor, a third diode, and the smoothing capacitor, a fourth diode connected to a connection point of a primary winding of the second transformer, the winding of the second transformer and the second switch, and to the one end of the smoothing capacitor, a third reactor connected to both ends of a series circuit of a secondary winding of the first transformer and a secondary winding of the second transformer, and a control circuit which alternately turns on the first s

Abstract: A current-mode controlled DC-DC converter includes a comparator comparing a first or second current detection signal with a first or second reference current that is based on an error voltage of a voltage detection signal, a pulse generator generating a first pulse signal whose ON time is longer than an interval between when the second current detection signal reaches a minimum value and when the second current detection signal reaches the second reference current, a pulse generator generating a second pulse signal whose ON time is longer than an interval between when the first current detection signal reaches a minimum value and when the first current detection signal reaches the first reference current, the second pulse signal being behind the first pulse signal by a half period, and a PWM circuit generating a first or second PWM signal according to the pulse signal and an output signal from the comparator, thereby turning on/off a switch.

Abstract: A DC/DC converter includes a first transformer and a second transformer each having primary windings and secondary windings respectively having first windings and second windings, a second switch connected to both ends of a first series circuit, a fourth switch connected to both ends of a second series circuit, a third series circuit being connected to both ends of the second switch and having the second winding and a second DC power supply, a fourth series circuit being connected to both ends of the fourth switch and having the second winding and the second DC power supply, a reactor connected to both ends of a series circuit having the secondary windings, and a control circuit turning ON/OFF the first and third switches with a phase difference of a half cycle and turning ON/OFF the second and fourth switches with a phase difference of a half cycle.

Abstract: A DC/DC converter according to the present invention includes first and second transformers, each including a primary winding and a secondary winding, the primary winding including first and second windings, a first diode connected to both ends of a series circuit including the DC power supply, a first switch, and the first winding of the first transformer, a second diode connected to both ends of a series circuit including the DC power supply, a second switch, and the first winding of the second transformer, a first series circuit connected to both ends of the first diode, the first series circuit including the second winding of the first transformer and a smoothing capacitor, a second series circuit connected to both ends of the second diode, the second series circuit including the second winding of the second transformer and the smoothing capacitor, a reactor connected to both ends of a series circuit including the secondary winding of the first transformer and the secondary winding of the second transform

Abstract: A swinging inductor is used to achieve zero-current switching in a resonant buck-type voltage converter. The swinging inductor exhibits the property of a relatively high inductance at zero current and low current, but it swings back to the original resonant inductance value at high current. In this way the high and medium regions of the current sine wave remain effectively unchanged. Upon circuit power application, the current rises slowly due to the high swinging inductance value, but this is an innocuous parasitic effect. Using the swinging inductance placed in series with a switching device to control the transfer of energy from the input source to the output load allows for a very efficient transfer of energy and it also prevents the current from becoming negative. Moreover, the efficiency level is sustainable over a wide range of input and output voltage requirements.

Abstract: A power regulator is provided which employs a resonant circuit and permits regulation between a certain maximum value and zero. A series resonant circuit is adjusted to regulate power by adjusting the correspondence between the resonance frequency and the frequency of the voltage source such as an AC source delivering a sine wave or a square wave. Further, the output voltage is regulated to be lower than the voltage of the AC source when output current is zero. A capacitance is connected in parallel with the output of the power regulator to form a second resonant circuit with the inductance of the series resonant circuit. A method of power regulation is also contemplated.

Abstract: In the voltage converter, a current flowing through a primary coil of a voltage transformer is turned on/off by FETs, an AC voltage induced at a secondary coil of voltage transformer is rectified and applied to a choke coil including two coils, a saturable choke coil and a flywheel diode are connected between two coils of the choke coil and the ground, and a saturable reactor is reset in response to the output voltage, whereby the output voltage is adjusted.

Abstract: A voltage regulator particularly adapted to A.C. distributed power systems requiring independent voltage regulation at a plurality of frequency responsive power supply modules energized by a power source at a common alternating frequency is provided by resonant tuning of the regulator circuit. An LC resonant circuit determines the operating frequency of the regulator, and may be operated above or below the excitation frequency. The output voltage is applied to a current amplifier which energizes a linearly variable inductor in accordance with the sensed D.C. output voltage. Changes in the output voltage result in changes in the tuned frequency of the LC circuit and the corresponding corrective change in the output voltage. Circuits providing both voltage and current regulation are described.

Abstract: A voltage regulator using electronic control of two static switch circuits to permit tap changing without arcing at the switched electrical contacts, without interrupting the load current, and without inducing sizable circulating currents. As a mechanical drive connects a new tap to the auxiliary winding, current through the new winding is blocked by an auxiliary static switch. The drive next opens the main switch delivering current to the load. The opening of the main switch immediately allows the main static switch circuit to "turn on" to prevent arcing and load interruption until the next current zero. The main static switch control senses no current passing through the main switch and ceases gating, and therefore conduction, of the main static switch. Since neither the main static switch nor the auxiliary static switch is conducting current from the auxiliary winding, the load voltage begins dropping and the voltage across the auxiliary static switch begins rising.