Abstract: A DC power source includes one or more insulation type DC-DC converters and a plurality of cells, and is capable of reducing an amount of power loss at an insulation type DC-DC converter. The DC power source includes a pair of terminals for outputting electric power, a fuel cell and a secondary cell connected in parallel to the pair of terminals. An insulation type DC-DC converter is connected in series to either one of the fuel cell or the secondary cell.

Abstract: A vehicle energy management system relying on the principle of reallocation of existing resources provided by the vehicle manufacture. Engine belt or engine direct driven components are replaced with electrical motors. Since replacement of the main fan unit would involve a prohibitively large fan due to starting currents, the larger component that would have multiple cooling purposes is replaced with smaller single function electrical components. The larger multipurpose heat exchangers such as the vehicle radiator are replaced with smaller single function heat exchangers associated with the smaller electric fans. The energy management system may involve a main vehicle engine crankshaft mounted generator. This simple generator creates high voltage DC electricity that may be converted to household level AC for the operation of customer application equipment.

Abstract: A stepping motor driving apparatus with dynamic torque control includes a motor controller, a motor driver, and a frequency-to-voltage converter. In practice, the clock signals are sent to the motor driver and the frequency-to-voltage converter. When the motor is required to increase its speed, the system will increase the frequency of the clock signal CK. The reference voltage Vr will synchronously increase and generate higher driving current to drive the stepping motor so that the torque becomes larger. Besides, when the system fails and causes the stepping motor to run stiff, the system will reduce the driving current to the minimum automatically. It effectively avoids excessive heating and increases the security to the system.

Abstract: A device for detecting the speed of a plural-phase motor in which a speed deviation occurring every m periods is eliminated, to provide a speed detection signal high in accuracy at low cost. The motor speed detecting device in which, among drive signals driving a plural-phase motor, m-phase drive signals (where m is a natural number which is not less than two (2) and equal to or smaller than the number of phases of said motor) are detected, and combined to form a signal, comprises a frequency divider adapted to subject the signal thus formed to 1/(m.times.n) frequency division (where n is a natural number).

Abstract: Provided is a brushless DC motor speed controller in which the speed feedback signal needed for speed control is obtained from the commutation signals generated by the magnetic-pole sensor in the brushless DC motor. The-brushless DC motor speed controller includes an edge detector, which generates a pulse each time a rising or falling edge is detected in the signal from the magnetic-pole sensor of the brushless DC motor. A frequency multiplier is used to multiply the frequency of the pulse train from said edge detector. A frequency-to-voltage converter is used to convert the output pulse train from said frequency multiplier into a positive analog voltage, with the level of the positive analog voltage being in proportion to the speed of the brushless DC motor. A motor rotating direction detecting circuit receives the output signal from said magnetic-pole sensor and thereby detects in which direction the brushless DC motor currently rotates.

Abstract: A device and method for cooling an internal combustion engine is disclosed in which a simple control circuit constructed of relatively inexpensive components enables the rotational speed of an electric motor employed in the cooling device to be controlled in adaptation to various temperature levels of a cooling circuit. The control circuit includes a power semiconductor which is used to drive the electric motor in certain speed ranges associated with predetermined temperature levels. The control circuit also incorporates a bypass circuit that permits the electrical motor to be driven in particular speed ranges without the use of the power semiconductor. Thus, the electric motor can be driven at one hundred percent of its speed capacity by eliminating a voltage drop associated with the power semiconductor.

Abstract: A magnetic or optical disk apparatus featuring a circuit for generating a dual implication MOTOR STATUS signal in response to a MOTOR SPEED signal representative of the speed of rotation of a disk drive motor and to a MOTOR ON signal dictating the rotation and nonrotation of the disk drive motor. The MOTOR STATUS signal indicates: (1) the rotation of the disk drive motor at a desired normal speed, enabling data transfer between the disk and a head; and (2) the slowing down of the motor to a predetermined speed close to zero. The two implications of the MOTOR STATUS signal can be distinguished from each other by reference to the MOTOR ON signal. The first implication may be used to enable reading or writing of data on the disk, and the second implication for disk ejection and for opening a power switch or switches, among other purposes.