Abstract: In a misfire detecting apparatus for a multicylinder internal combustion engine, a rotational signal outputting unit outputs a rotary signal at every predetermined rotary angle, and a tentative misfire decision unit tentatively decides, on the basis of the rotary signal, whether or not misfire has occurred in each cylinders of the engine. A tentative misfire number counting unit counts the number of tentative misfires decided for respective cylinders, and a counting result storage unit stores the counting results. After a given number of tentative misfire decisions have been made, it is decided that misfire has actually occurred, only if the counting result, for a part of the cylinders, among the counting results for respective cylinders stored in the counting result storage unit is larger than a predetermined number.

Abstract: An apparatus for detecting occurrence of misfire in a multicylinder internal combustion engine detects a rotational speed of the engine in each expansion stroke of each cylinder, calculates a change of the engine rotational speed fluctuation quantity in accordance with a value of the detected rotational speed, and sets a misfire determination value for each cylinder based upon a determination result of the engine operating condition. Misfire determination is made for each cylinder based upon the misfire determination value for each cylinder and the change of the rotational speed fluctuation quantity, thereby elevating the accuracy of detecting occurrence of misfire in each cylinder.

Abstract: A method of operating a disk player that reproduces information recorded on a disk. Programs on the disk are addressed from a directory in a memory and the programs are sequentially accessed according to the order in the directory. The directory can be filled by inserting random numbers or by scanning through the programs or over the tracks. A table of contents at the beginning of the disk is read if possible. The tracks can be scanned and only tracks having new programs are reproduced. Also a playback position servo operates with a dead-zone in the drive voltage.

Abstract: A pulse-width modulation drive circuit for a load such as a motor, particularly, a motor used in a compact disc player or the like, in which losses in diodes used to absorb reverse EMF are substantially eliminated. For this purpose, the pulse widths of pulse signals used to on-off control drive current flow through the load are controlled so as to eliminate the diode losses. The circuits of the various embodiments of the invention are designed so as to be easily implemented in integrated circuit form.