Abstract: A transformer has a primary winding connected between a pair of dc input terminals via a switch, a secondary winding connected between a pair of output terminals via a first rectifying and smoothing circuit, and a tertiary winding connected to a second rectifying and smoothing circuit for feeding a switch control circuit. Included in the switch control circuit is a switch control pulse generator circuit whereby the switch is driven to provide a constant dc voltage at the output terminals. A mode selector circuit is connected to the switch control pulse generator circuit to cause the switch to be driven continuously under normal load, and at intervals under light load. The intermittent driving of the switch is suspended, and the switch driven continuously, in the event of a drop in the output voltage of the second rectifying and smoothing circuit to a predefined value during operation in light load mode.

Abstract: When an AC power source (1) is turned on, energy is accumulated in a backup capacitor (63) by an energy supply circuit (64). An internal power source (65) supplies the energy accumulated in the capacitor (63) to a control unit (49). Thus, a power factor improvement circuit (40-2) operates. When the power factor improvement circuit (40-2) operates to output a predetermined voltage, an output voltage detection circuit (67) detects the voltage, and switches the internal power source (66) on. The turned on internal power source (66) supplies the energy in the capacitor (63) to a control unit (56) to operate a DC/DC conversion circuit (50). In this way, by operating the DC/DC conversion circuit (50) after operating the power factor improvement circuit (40-2), the capacity of the capacitor (63) can be reduced.

Abstract: A switching power supply such that the step-up ratio of when the power-factor is improved does not increase, and the conversion efficiency can be improved. In a case where the error voltage Ver outputted from a conductance amplifier (23) increases over a reference voltage Vref2, a switching signal of high level is outputted from a comparator (59) to a FET (57) to turn on the FET (57). Therefore a resistor (56) is bypassed, and as a result a reference voltage Vref1 inputted into the conductance amplifier (23) is changed from a reference voltage Vref1-1 to Vref1-2 of lower level. Further, since the variation of the error voltage Ver outputted from the conductance amplifier (23) decreases, the output voltage Vout also decreases.

Abstract: Management information is read from an information storage medium having the management information recorded thereon, the management information including track number information imparted to at least one track and group management information for managing as selective recording information one or a plurality of tracks as one group. Judgment is then made upon whether the group management information is included in that management information. A display mode is changed depending on a case where the group management information is recorded and a case where it is not recorded, and it is then displayed in a displaying device.

Abstract: A switching power supply such that the step-up ratio of when the power-factor is improved does not increase, and the conversion efficiency can be improved. In a case where the error voltage Ver outputted from a conductance amplifier (23) increases over a reference voltage Vref2, a switching signal of high level is outputted from a comparator (59) to a FET (57) to turn on the FET (57). Therefore a resistor (56) is bypassed, and as a result a reference voltage Vref1 inputted into the conductance amplifier (23) is changed from a reference voltage Vrefl-1 to Vrefl-2 of lower level. Further, since the variation of the error voltage Ver outputted from the conductance amplifier (23) decreases, the output voltage Vout also decreases.

Abstract: Management information is read from an information storage medium having the management information recorded thereon, the management information including track number information imparted to at least one track and group management information for managing as selective recording information one or a plurality of tracks as one group. Judgment is then made upon whether the group management information is included in that management information. A display mode is changed depending on a case where the group management information is recorded and a case where it is not recorded, and it is then displayed in a displaying device.

Abstract: Management information is read from an information storage medium having the management information recorded thereon, the management information including track number information imparted to at least one track and group management information for managing as selective recording information one or a plurality of tracks as one group. Judgment is then made upon whether the group management information is included in that management information. A display mode is changed depending on a case where the group management information is recorded and a case where it is not recorded, and it is then displayed in a displaying device.

Abstract: A dc-to-dc converter includes a transformer having a primary winding connected to an input rectifying and smoothing circuit via an FET or like switching device, and a secondary winding connected to an output rectifying and smoothing circuit. A resonance capacitor is connected in parallel with the switching device. A switch control circuit cyclically turns the switching device on and off so as to keep constant the output voltage of the output rectifying and smoothing circuit by feedback control. The switch control circuit drives the switching device in light load mode when a flyback voltage developed by the transformer terminates earlier than each clock pulse, and in heavy load mode, in which each on-off cycle of the switching device is longer than in the light load mode, when the flyback voltage terminates later than each clock pulse.

Abstract: A switching power supply comprising an a.c.-to-d.c. converter circuit for connection to a source of commercial alternating current, and a d.c.-to-d.c. converter circuit for translating the d.c. output voltage of the a.c.-to-d.c. converter into desired d.c. voltage for application to a load. The d.c.-to-d.c. converter circuit is set into operation only after the output voltage of the a.c.-to-d.c. converter circuit has built up sufficiently, in order to preclude instability in the output voltage of the power supply during a startup period.

Abstract: A switching power supply comprising an a.c.-to-d.c. converter circuit for connection to a source of commercial alternating current, and a d.c.-to-d.c. converter circuit for translating the d.c. output voltage of the a.c.-to-d.c. converter into desired d.c. voltage for application to a load. The d.c.-to-d.c. converter circuit is set into operation only after the output voltage of the a.c.-to-d.c. converter circuit has built up sufficiently, in order to preclude instability in the output voltage of the power supply during a startup period.

Abstract: A dc-to-dc converter includes a transformer having a primary winding connected to an input rectifying and smoothing circuit via an FET or like switching device, and a secondary winding connected to an output rectifying and smoothing circuit. A resonance capacitor is connected in parallel with the switching device. A switch control circuit cyclically turns the switching device on and off so as to keep constant the output voltage of the output rectifying and smoothing circuit by feedback control. The switch control circuit drives the switching device in light load mode when a flyback voltage developed by the transformer terminates earlier than each clock pulse, and in heavy load mode, in which each on-off cycle of the switching device is longer than in the light load mode, when the flyback voltage terminates later than each clock pulse.

Abstract: In the switching power supply, a load state judgment circuit (25) judges the state of a load (20) according to a pulse signal VG to be used for ON/OFF control of a MOS transistor (8) as a switching element in a DC—DC converter (127). In order to reduce a power consumption of the switching power supply, a PFC ON/OFF switching circuit (24) stops the operation of the power factor improving converter (126) when the judgment result indicates a light load state, and starts the operation of the power factor improving converter (126) when the judgment result indicates a heavy load state.

Abstract: In the switching power supply, a load state judgment circuit (25) judges the state of a load (20) according to a pulse signal VG to be used for ON/OFF control of a MOS transistor (8) as a switching element in a DC-DC converter (127). In order to reduce a power consumption of the switching power supply, a PFC ON/OFF switching circuit (24) stops the operation of the power factor improving converter (126) when the judgment result indicates a light load state, and starts the operation of the power factor improving converter (126) when the judgment result indicates a heavy load state.

Abstract: A serial circuit of the primary winding (21) of a transformer (2), a switching device (3) and a current-detecting resistor (4) is connected between a pair of dc terminals (18, 19). A smoothing capacitor (7) is connected to the secondary winding (22) of the transformer (2) via a diode (6). A resonance capacitor (5) is connected in parallel with the serial circuit of the switching device (3) and the current-detecting resistor (4). The current detection signal, the output voltage detection signal, and the switch voltage detection signal are combined to provide control pulses for the switching device (3). A control circuit (13) includes a minimum non-conducting period determination circuit for setting a first and a second minimum nonconducting period with hysteresis. The nonconducting periods of the switching device are placed under the limitation of the minimum nonconducting periods when the load is light.

Abstract: When a detection device detects any kind of change regarding track recording after the start of the track recording a grouping instruction is given to information attaching and generating device. Then, the information attaching and Generating device attaches the same group name information to a group, in which a track where the recording has been started in an information recording medium to a track recorded at the point when the grouping instruction has been received are made to be the same group, and group control information is generated. Therefore, since the grouping is automatically performed by any kind of change regarding the track recording, a user can omit the operation that he/she performs the grouping by himself/herself, and thus the operation load of the user can be reduced.

Abstract: Management information is read from an information storage medium having the management information recorded thereon, the management information including track number information imparted to at least one track and group management information for managing as selective recording information one or a plurality of tracks as one group. Judgment is then made upon whether the group management information is included in that management information, A display mode is changed depending on a case where the group management information is recorded and a case where it is not recorded, and it is then displayed in a displaying device.

Abstract: The switch-mode dc power supply includes a series circuit, a rectifier, an output smoothing circuit, detection circuit, an adding circuit, a triangular wave generator and a control signal generator. The series circuit includes a primary winding of a HF transformer, a semiconductor switching element and a current detection unit connected between two output terminals of a rectifier/smoothing circuit. The rectifier is connected to an end of a secondary winding of the HF transformer. The output smoothing circuit is connected between the rectifier and other end of the secondary winding. The detection circuit is connected to a connection point between the rectifier and the output smoothing circuit. The adding circuit is connected between the detection circuit and a connection point between the semiconductor switching element and the current detection unit. The adding circuit has a current mirror and a current detector. The triangular wave generator is connected to the adding circuit.

Abstract: A power supply system has a switching element to be turned on and off for d.c. to d.c. conversion of a unidirectional supply voltage in synchronism with horizontal synchronizing pulses used for line by line synchronization in a computer display. Since commercial computer systems commonly make selective use of horizontal synchronizing pulses at two different repetition rates, one of which is too high for driving the switching element, the horizontal synchronizing pulses generated at either rate are directed into an amplitude modulator circuit where the pulses are modulated to have either of two different predetermined amplitudes according to their repetition rates. The repetition rate of the horizontal synchronizing pulses being generated is determined from the amplitude of the amplitude modulated horizontal synchronizing pulses, and the switching element is driven at the lower rate even if the horizontal synchronizing pulses are being generated at the higher rate.

Abstract: An automobile mirror assembly improves safety during driving of a car by widening the visual field of the driver with little distortion. The mirror is mounted on a car with a support member and a holding member to be adjustable in its position. A gradually changing mirror section is provided on at least one of an upper, lower and side edges of a main mirror section of the mirror. A surface of a gradually changing mirror section is defined by a plurality of intersections between curved surfaces provided in at least one of a vertical and horizontal directions with hyperbolic curves provided in a direction perpendicular to one of the vertical and horizontal directions. Each respective curved surface passes through circular arcs, the radii of curvatures of the circular area being calculated from Equation 1 indicated below. The radii of curvatures of the circular arcs gradually become smaller in an extending direction.

Abstract: A magnetic tape cassette recording and playback apparatus, particularly for digital audio tapes, capable of performing a variety of controlled playback and recording operations in accordance with a user-inputted program. The cassettes are stored on shelves in a magazine and selectively extracted and transported to a drive unit for playing and recording. In one mode, the apparatus can carry out continuous recording from one cassette to another, and cassettes can be designated for recording, for instance, of only particular types of music. The cassettes are rewound at the completion of a playing program so as to be ready for the start of search operations for a subsequent program.