JPS614498A - Driving method of multispeed pulse motor - Google Patents

Abstract

PURPOSE:To reduce power loss by intermittently flowing a current in a high frequency of the prescribed rate with respect to a phase drive signal in synchronization with the phase drive signal, thereby supplying a power matched to the speed. CONSTITUTION:Phase drive signals A, B, inversion signal A, inversion signal B of a frequency fA are supplied to transistors Tr1-Tr4. A signal f1 of the frequency higher than the frequency fA is applied to a transistor Tr0. However, the signals f1, fA have the prescribed ratio and are synchronized. Thus, a small current can be flowed at a low speed, a large current can be flowed at a high speed, thereby performing the operation with less vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for driving a multi-speed pulse motor suitable for use in printers and the like.

FIG. 3 is a diagram showing an example of a pulse motor drive circuit using the conventional L/R method, and as is well known, A.

Signals with phase differences are applied to terminals B, A, and 100, respectively, and the pulse motor 1o rotates as the excited winding portion moves. Therefore, the conventional motor drive method has the above-mentioned 1. /R method is common, but
Recently, constant current drive has also been used. However, since pulse motors move in steps, if you use multiple speeds to reduce vibration at high speeds, too much power will be supplied at low speeds and vibration will increase, and vice versa, if the power is insufficient at high speeds, it will step out. Furthermore, when moving at high speed, the value of R in L/R must be increased, so power loss due to resistance R becomes extremely large.

Purpose The present invention was made in order to solve the drawbacks of the prior art such as - It is something.

The configuration of the present invention will be described below based on one embodiment.

FIG. 1 is a diagram showing an example of an electric circuit used for carrying out the pulse motor driving method according to the present invention, in which a transistor T
Signals similar to the phase drive signals A, B, A, and ■ in the conventional circuit shown in FIG. 3 are supplied to r1 to Tr4.

Now, let that frequency be f^. Also 1, transistor T
A signal f having a frequency higher than the frequency f^ is applied to ro. However, fl and f^ have a certain ratio. In addition.

It is desirable that fl and f8 be synchronized; if they are not synchronized, vibrations will increase.

Figure 2 is a waveform diagram showing the relationship between the signal f^+f+ and the load current iL, in which (a) is for low speed, (b) is for medium speed, and (c) is for high speed. In the example case, the signal f
, (however, the pulse width Pw is constant) is a signal with a frequency five times that of the signal f^ depending on the speed.

Therefore, since the current i1 flows according to the electrical time constant of the motor, only a small amount of current flows at the low speed (q), and only a small amount flows at the medium speed (b) before the current decreases sufficiently due to discharge. Since the next pulse is given to , the average current (dashed line) is larger than that in case (a). The average current will be large. Also, at this time, if you add a resistor R externally to reduce the electrical time constant of the motor, the operation of the motor will be stabilized. Although we have only explained the case of , it goes without saying that in principle there may be any number of pairs.

Cram School - Ichira As is clear from the above explanation, according to the present invention, it is possible to flow a small current at low speeds and a large current at high speeds, so it is possible to perform operation with less vibration at each speed. . Additionally, compared to conventional drive methods, it is possible to supply power commensurate with the speed, which has the advantage of reducing power loss.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an electric circuit used to implement the pulse motor driving method according to the present invention, FIG. 2 is a waveform diagram for explaining the operating principle of the present invention, and FIG. 3 is a diagram showing a conventional electric circuit. FIG. 3 is a diagram showing an example of a pulse motor drive circuit. 10...Pulse motor, L...Winding, Tro-Tr
4. Transistors and Figure 1 Figure 3 Figure 2 w

Claims (1)

[Claims] A multi-speed pulse motor characterized in that the current is intermittent in synchronization with a phase drive signal and at a high frequency that is a fixed ratio with respect to the phase drive signal, and the current is supplied in accordance with the rotational speed of the motor. Driving method.