Nippondenso Co., Ltd.

Robert Boschgmbh

Toyota Jidosha Kogyo Kabushiki Kaisha

Suguru Sato

Kazumasa Mori

Yutaka Suzuki

Yoshihiko Tsuzuki

Nobuhito Hobo

Osamu Ito

Itsushi Kawamoto

Hironari Nukata

Kenro Sekino

Yoshihiko Huruya

Yoriaki Iwata

A first and a second full-wave rectifying network are respectively connected with both ends of generating coils of a generator for respectively generating alternating current thereat. A switching device has normally closed contacts for making voltage differences among the input terminals of the second full-wave rectifying network zero, whereby the coils act as a star-connected current generating winding so long as the contacts are held closed. The switching device also has an energizing coil for actuating the normally-closed contacts to open when the rotational speed of the generator exceeds a predetermined value. When the normally-closed contacts are opened, the coils no longer act as the star-connected winding but an independently generating winding, to thereby increase the output current from the generator even when the generator operates at a relatively high rotational speed. A terminal circuit having a resistor and diodes connected with input terminals of the first full-wave rectifying network supplies base current for a switching transistor of a voltage regulator so that the voltage regulator establishes a separate field excitation at an earlier stage of the rotational speed of the generator.

Current generating system with output winding switching device

To prevent unusually high or low voltage output from an automotive-type alternator, in case of failure of connection from the alternator rectifier output to the automotive vehicle battery, a connecting network is provided connecting an auxiliary alternator output terminal to the voltage sensing circuit to control the voltage sensing circuit to in turn control the field current to the alternator to prevent excessive output voltages. Additionally, a further voltage sensing circuit is connected to the auxiliary terminal to provide limited energization to the field for self-excitation of the generator if the vehicle engine, driving the generator is started, for subsequent transfer of control to the main voltage sensing circuit, but to prevent continuous field current flow at full field current value to prevent burnout of the field in case the engine is not started, but the main vehicle switch, typically the ignition switch, is left closed.

Electrical generating system, particularly for automotive use

To provide a-c output at a voltage substantially higher than normal automotive voltage of 12-24 V, for example output voltage in the 80 to 90 V range to operate windshield and other glass pane heaters, a three-phase alternator is star-connected and has two armature windings which, for example, may be serially connected or may be separately wound, on the same stator, one winding being of comparatively few turns of heavy wire and connected to a rectifier to provide normal d-c on-board voltage for the vehicle, stored in a battery, the voltage being controlled by a voltage regulator connected to the d-c output terminals; the other winding, for example of a much larger number of turns of finer wire providing the high-voltage output at terminals adapted for connection to the heater wires in the windshield, or rear windows, or other window panes.

Double-voltage, automotive-type alternator

A pair of diodes, which has an input terminal connected with a neutral point of a Y-connected output winding of an alternating current generator, is provided in addition to a full-wave bridge rectifier connected across a battery. A field winding of the alternating current generator is supplied with filed current from the battery or the full-wave bridge rectifier and further from the pair of diodes which are energized by the voltage appearing at the neutral point. The field current supply from the pair of diodes is not limited by a voltage regulator for controlling the output voltage of the generator, whereby a large increase of output power of the generator can be obtained.

Alternating current generator

A first and a second full-wave rectifying network are respectively connected with both ends of phase coils of a current generator for respectively generating alternating current thereat. A first and a second additional diode are respectively connected between both positive and negative direct current terminals of the first and second full-wave rectifying network. A switching device has normally closed contacts connected across the positive and negative terminals of the second full-wave rectifying network, whereby the phase coils act as a star-connected current generating winding so long as the contacts are held closed. The switching device also has an energizing coil for actuating the normally-closed contacts to open by the electromotive force thereof when the rotational speed of the generator exceeds a predetermined value. When the normally-closed contacts are opened, the phase coils no longer act as the star-connected winding but as independently generating windings, to thereby increasing the output current from the generator even when the generator operates at a relatively high rotational speed.

Generator system with speed responsive output winding switching device

A rectifier assembly is installed in an alternating current generator for providing D.C. current. The rectifier assembly includes a positive and negative cooling fin on which positive and negative diodes are respectively fixed, and interconnecting leads for respectively connecting each of the positive diodes with each of the negative diodes, wherein at least one of the interconnecting leads is disposed in slots of the stator core of the generator, whereby the interconnecting leads become resistant to line-failure or the like due to violent vibration.

Rectifier assembly

There is provided a vehicle engine-driven alternator wherein an internal combustion engine is coarsely adjusted to a preset speed by an engine governor, the turning driving force of the engine is transmitted to an alternator through a magnetic slip coupling, and the excitation current to the magnetic slip coupling is controlled by an excitation control circuit which compares the number of revolutions of the alternator with a preset value to generate an output depending on the result of the comparison, thereby providing a source of alternating current having an extremely accurate preset frequency.

Growing community of inventors

Ohbu, Japan

Suguru Sato