JPS5874114U - Rotational phase detection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a rotating magnetic head device, Fig. 2 is a bottom view of a rotating drum, Fig. 3 is a bottom view showing an example of a rotating drum suitable for use in this invention, and Fig. 4 is a bottom view of a rotating drum suitable for use in this invention. FIG. 5 is a system diagram showing an example of the device, FIG. 5 is an explanatory diagram of its operation, FIG. 6 is a connection diagram showing a specific example of FIG. 4, and FIG. 7 is an explanatory diagram of its operation. 2 is a rotating drum; M1 to M6 are magnets 1-14°6 are first and second waveform shaping circuits. 7 is a panel width variable circuit;
8 is an AND gate, and P6 is a detection pulse used for rotational phase control. Figure 1 Figure 2

Claims (1)

[Scope of utility model registration request] It has a plurality of magnets arranged at equal intervals in the circumferential direction of the rotating drum, and first and second detection coils arranged close to the plurality of magnets, and the first and second detection coils are arranged close to the plurality of magnets.
The rotational speed of the rotating drum is detected by the output signal of the detection coil, and one of the plurality of magnets is arranged with the polarity opposite to the other magnets to serve as a rotational phase detection magnet. A rotational phase detection device characterized in that it uses a rotational phase detection coil and selectively extracts only a signal of a magnet for rotational phase detection from a signal detected by the first detection coil.