JPH0469872A - Stepping motor driving circuit for flexible disk device - Google Patents

Abstract

PURPOSE:To reduce the current consumption by supplying power to keep the position regardless of oscillation and shock at the time of the end of seek. CONSTITUTION:Each time a signal STP is sent from a host, the states of D type flip flops 3-1 and 3-2 are changed, and four elements out of switching elements 12-1 to 12-12 corresponding to them are turned on, and the current flowing direction in a winding is changed. A magnetic head is fed by one step at each time. When the signal STP is continuously sent from the host within a certain time, a monostable multivibrator 8 is triggered to continuously output high level '1'. If the signal STP does not come for the certain time or longer, the output of a monostable multivibrator 8 goes to low level '0', and the current is reduced to 1/2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stepping motor drive circuit for a flexible disk device, and particularly to a stepping motor drive circuit for a flexible disk device, and particularly for a stepping motor drive circuit that drives a four-phase stepping motor having a center tap and uses a single power source. Bing motor drive circuit.

1. Prior Art] An example of a conventional stepping motor drive circuit using a single power source is shown in FIG. 4 and will be described.

In FIG. 4, which shows an example of the stepping motor drive circuit of this conventional flexible disk device, 1 is an up/down counter, and this up/down counter 1 receives one input from the DIR (Direction) signal sent from the host. Exclusive OR circuit 2-1 with connection ζf+
and this exclusive OR circuit 2-1. An exclusive OR circuit 2-2 has one input connected to its output, and an STP (s top) is signal whose output is connected to the D input and is sent by post. is connected to the CK large input and is a flexible disk device! A D-type flip-flop 3-1 has an R input connected to a TKO (Track Zero) signal indicating the outer circumference limit of the magnetic head.
, its own Q output is connected to the D input, and the CK large input ST
Pm is connected to the R input, and the TKO signal is connected to the R input.

4 is a decoder connected to each Q output of D-type flip-flops 3-1 and 3-2; 5-1, 5-2, and 5-3;
and 5-4 are windings whose ends are connected to each other and whose connection points are connected to a single power supply 7 (VDD), 6-1
．． 6-2 and 6-3.6-4 each have one end connected to the winding 5.
-1, S-2 and 5-3°5-4 are connected to the non-interconnected sides, the other i is connected to the ground side, and the control input is connected to the output of the decoder 4.

Table 1 below is a truth table of the decoder 4 in FIG.

Table 1 In this Table 1, Q+ and Qo represent the Q outputs of D-type flip-flops 3-1 and 3-2, and G1.
+ G2 * Gl r c, from the decoder 4 to the switching cables 6-1, 6-2, 6-3, 6-
The signals supplied to each gate of 4 are shown.

Figure 5 is a time chart used to explain the operation of Figure 4.
(a) shows the TKO signal, (b) shows the Di
R Shinzuki Dogetsu c) is STP Shinzuki Dogetsu d) is the Q output Qx of the D-type flip-flop 3-1, (e) is the Q output Q o of the D-type flip-flop 3-2, (f), ( g)
, can), (1) are the signals G1. G
This shows 2°G 3 + G4.

Next, the operation of the stepping motor drive circuit shown in FIG. 4 will be explained with reference to FIG. 5.

First, each time the -i STP signal rises as shown in FIG. 5(c), the up/down counter 1 counts up when seeking to the inner circumference, and counts down when seeking to the outer circumference. Next, according to the count value of this up/down counter 1, the decoder 4 outputs the output from the
)l), (h), (i) signal G1. G.
.

G* r G4 causes switching elements L-1, 6-
2°6-3 and L-4 respectively operate.

After the seek operation is completed, the last state is maintained as it is, and one of the switching elements 6-1 and 6-2 and one of the switching elements 6-3 and 6-4 are connected.
The two switching elements serve as a trench in the ON state.

FIG. 6 is a circuit diagram showing another example of a stepping motor drive circuit for a conventional flexible disk device.

In FIG. 6, parts that are the same as those in FIG. 4 are designated by the same reference numerals, and their explanation will be omitted. 8 is a monostable multivibrator (MM)-1' connected to the STP signal, and this monostable multivibrator 8 is configured to output a pulse for a certain period of time from the rising edge of the STP signal. 9 is a decoder connected to each Q output Q+, Qo of the D-type flip-flop 3-1, 3-2 and the output of the monostable multivibrator 8; this decoder 9 is connected to the D-type flip-flop 70 tube 3-1.3
-2 and each output of the monostable multivibrator 8 to change the υ output.
(a) shows the TKO signal, (b) shows the DI
(C) is the STP device, (d) is the output of the monostable multi-bi break 8, (e) is the D-type flip-flop 3.
-1 Q output Q! , (f) is a D-type flip-flop 3
-2 Q outputs Qo - (g), (hL (1), (j) are respectively output from the decoder 9 to the switching cables 6-1 to 6-
The signal c supplied to each gate of 4, T ct l G
3°G4 is shown.

In the circuit shown in FIG. 6, the operation when the STP signal is input is the same as in the circuit shown in FIG. -4 are all off (OFF)
be done.

[Problem to be solved by the invention]

In the conventional stepping motor drive circuit of the flexible disk device shown in FIG. 4 described above, the switching element remains on even after the end of the seek, so current continues to flow, resulting in a problem of high power consumption. In addition, in the stepping motor drive circuit of the conventional flexible disk device shown in Fig. 6, all switching elements are turned off after the seek is completed, so power consumption is small, but if vibration or shock is applied in this state, the position will change. The problem was that it was easy to change.

[Means to solve the problem]

A stepping motor drive circuit for a flexible disk device according to the present invention includes a first exclusive OR circuit whose one input is connected to a DIR signal sent from a host;
a second exclusive OR circuit, one input of which is connected to the output of the exclusive OR circuit; and the output of this second exclusive OR circuit is connected to the D input, and the S
A first D-type flip-flop to which the TP signal is connected to the CK large input and the TKO signal indicating the outer circumferential limit of the magnetic head of the flexible disk device is connected to the R input.

The Q output is connected to the D input and the CK large input is connected to the STP above.
an up-down counter consisting of a second D-type 7 lip-flop to which the TKO signal is connected and whose R input is connected, a monostable multivibrator connected to the STP bond, and the first and second D type flip 70
a decoder connected to each Q output of the knob and the output of the monostable multivibrator, first and second windings which apply magnetomotive force to the stepping motor and whose ends are connected to each other; Third and fourth windings are located electrically 90 degrees apart from the first and second windings and have one ends of the windings connected to each other, and one end of the first windings is connected to each other. first and second switching elements whose other ends are connected to the power supply and ground side and whose control inputs are connected to the output of the decoder;
third and fourth switching elements connected to the connection point of the winding, the other ends of which are connected to the power supply and ground side, and the control inputs of which are connected to the output of the decoder, and one end of which is connected to the second winding. fifth and sixth switching elements having one control input connected to the output of the decoder and one end connected to the non-interconnected side of the decoder and the other end connected to the said 1PLm and ground side; a seventh and an eighth switching element connected to the non-interconnected side of the line, the other end connected to the upper power supply and ground side, and a control input connected to the output of said decoder; ninth and tenth switching elements connected to the connection point of the and fourth windings, the other ends of which are connected to the power supply and the ground side, and the control inputs of which are connected to the output of the decoder;
an eleventh and a first winding having one end connected to the non-interconnected side of said fourth winding, the other end connected to said power supply and ground side, and a control input connected to the output of said decoder;
2 switching elements.

[For production]

In the present invention, after the seek is completed, electricity is applied so as to maintain the position even if there is vibration or impact.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

4. FIG. 1 is a circuit diagram showing an embodiment of a stepping motor drive circuit for a flexible disk device according to the present invention.

In FIG. 1, the same reference numerals as in FIG. 4 and Section 6 indicate corresponding parts, and 10 is a D-type flip-flop 3-
1. Decoders, I L-1, and 11-2 connected to each Q output of 3-2 and the output of monostable multivibrator 8 provide magnetomotive force to the stepping motor, and one end of the windings are connected to each other. Winding 11-3゜11-4 is this winding 11-1
．． Windings located electrically 90 degrees apart from 11-2, with one end of the windings connected to each other, 12-1, 12-2
is a switching element whose one end is connected to the non-interconnected side of the winding 11-1, the other end is connected to the power supply 13 (year - power supply VDD) and the ground side, and whose control input is connected to the output of the decoder 10; One end of 113, 1i4 is connected to the connection point of windings Ii, 1lli 1-1, 11-2, and the other end is connected to the t source 13 and the ground side.
A switching element 125.12-6 whose input is connected to the output of the decoder 10 has one end connected to the 4 [4] of the winding 11-2.
1113 and the ground side, and the control input is connected to the output of the decoder 10. 12-. 7°12
-8 is a switching element 12-9 whose one end is connected to the interconnection side of the winding 11-3, the other end is connected to the power supply 13 and the ground side, and whose control input is connected to the output of the decoder 10; , 1:2-1. ．． 0 has winding 11 at one end
12-11.12- a switching element connected to the connection point of 3.11-4, the other end connected to the power supply 13 and the ground side, and the control input connected to the output of the decoder 10;
A switching element 12 has one end connected to the non-interconnected side of the winding 11-4, the other end connected to the power supply 13 and the ground side, and a control input connected to the output of the decoder 10.

And monostable multivibrator (MM) 8 is 8TP
The decoder 10 is a decoding circuit that outputs a pulse for a certain period of time from the rise of the signal, and changes the output by the output of D-type flip-flops 31 and 3-2 and the monostable multivibrator 8, and has the truth values shown in Table 3 below. have.

Switching elements 12-1 to 12-12 in Table 3 are FET switches that turn on when a no level is input to the gate.
Winding 11-1.11-2 is 1 with center tap
The set of windings are wound at electrically equal positions, as shown in Figure 2a, which is a diagram showing the electrical positions of the windings of a stepping motor. Winding 11-3.11-4 is also a set of windings with a center tap, and is located electrically 90 degrees apart from winding 11-1.11-2, as shown in Figure 2b. It's wrapped.

14 indicates a rotor.

Figure 3 is a time chart used to explain the operation of Figure 1.
(i) shows the DIR signal, (b, 1 shows the S
TP signal, (CJ is the TKO signal, (d) is the output of the monostable multipipe rake (MM) 8, (e) is the Q output Qx of the D-type flip-flop 3-1, (f7 is the D-type flip-flop 3-1) Q output QO% (g), (h), (it
, (j).

It), (c), (n), (o), φ)
, (q), and (r) are the prime numbers c, l c, + G5G4 + (Jl
i + G6 +07 1GM +09 1GI
This shows O+Gll r G12.

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to FIG. 3.

First, it is assumed that the magnetic head is at the outer circumferential limit as an initial value. At this time, each Q output Q+, Qo of the D-type flip 70 tube 3-1, 3-2 is at the L level rOJ.

The DIR signal sent from the host indicates the theta direction of the magnetic head, and an L level indicates an inner circumference seek, and an H level indicates an outer circumference seek.

Monostable multivibrator (MM) 81d Lv
Since krOJ is output to decoder 1 in the initial state,
0 is the signal Gl (see Fig. 3 (gl)), GM (see Fig. 3 (see 4), GM (see Fig. 3 G)) r Gi+ (
(see FIG. 3(Q)), and outputs H level "1" to each of the switching cables 12-1.12-6.12-8.1.
2-11 are respectively turned on, and the current flows from power supply 13 (VDD) - switching element 12-1 winding [11-1 - winding 11-2 - switching element 12-6 and power supply 13 (VDD) - switch f m child 12
11-winding 11-4-winding 11-3-switching element 12-8, and the windings include winding 11-1, winding 11-2,
A current determined by the series resistance of the windings 11-3 and 11-4 flows. This current value is determined by the winding 111.11-2.
This is 1/2 of the case when flowing alone to N-3 and 11-4.

Next, when the host inputs the STP signal (see Figure 3(b)), the Q output Q1 of the D-type flip-flop 3-1 becomes H level "1" at the rising edge of the signal. Also, the output of monostable multivibrator (MM) 8 (third
The figure (dl#) is also at H level 11. Decoder 10
The output is the signal Gl * G4 r G7 +Gio is H
Level "1" 9, switching element 12-1.12
-4.12-7.12-10 is turned on.

And the current is power supply 13 (VDD) - switching element 12-1 - winding 11-1 - switching element 12-4 and power supply 13 (VDD) - switching element 12-7
The current flows in the order of the winding 11-3 and the switching cable 12-10, and the current has a value determined by the resistance of one of the windings 11-1 and 11-3. The magnetic head is now advanced by one step of the stepping motor.

Thereafter, each time an STP signal is sent from the host, the state of the D-type flip-flops 3-1, 3-2 changes, and the corresponding four of the switching elements 12-1 to 12-12
turns on, and the winding direction changes. The magnetic head is advanced one step each time.

When the STP signal is continuously sent from the host within a certain period of time, the monostable multivibrator is retriggered and continues to output an H level "1". If this STP signal is strong for more than a certain period of time, the monostable multivibrator 8
When the output is at L level rOJ, the current becomes 1/2.

〔Effect of the invention〕

As described above, the present invention has the effect that after the end of the seek, the current is applied so as to maintain the position even if there is vibration or impact, and the attenuation flow can be reduced. Further, during the seek operation when the 5Tp4@ number is input from the host and the output of the monostable marza vibrator is at H level "1", the seek operation is equivalent to the conventional seek operation.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing one embodiment of a stepping motor drive circuit of a flexible disk device according to the present invention, and FIG.
The figure is an explanatory diagram showing the electrical potential IN of the winding of the stepping motor, FIG. 3 is a time chart for explaining the operation of FIG. 1, and FIG. 4 is a diagram of the stepping motor drive circuit of a conventional flexible disk device. 1 ('II), Figure 5 is a time chart for explaining the operation in Figure 4, and Figure 6 is a circuit diagram showing
This figure is a circuit diagram showing another example of a stepping motor drive circuit of a conventional flexible disk device, and FIG. 7 is a time chart for explaining the operation of FIG. 6. 1.asψ up/down counter, 2-1.22...
・Exclusive OR circuit, 3-1.3-2... φD type flip-flop, 8... monostable multi-high-1' rake, 10...-decoder, 11-1 to 11-4 ・
...Winding, 12-1 to 12-12 ...-Switching element, 13...Fist/power supply. Patent applicant Gunma NEC Co., Ltd.

Claims (1)

[Claims] A first exclusive OR circuit whose one input is connected to the DIR signal sent from the host, and a second exclusive OR circuit whose one input is connected to the output of the first exclusive OR circuit. The output of the second exclusive OR circuit is connected to the D input, the STP signal sent from the host is connected to the CK input, and the TKO signal indicating the outer circumference limit of the magnetic head of the flexible disk device is connected to the R input. A first D-type flip-flop is connected to the first D-type flip-flop, and a second D-type flip-flop has its @Q@ output connected to its D input, the STP signal connected to its CK input, and the TKO signal connected to its R input. an up/down counter configured with a monostable multivibrator connected to the STP signal;
and a decoder connected to each Q output of the second D-type flip-flop and the output of the monostable multivibrator, and a first and second decoder which applies a magnetomotive force to the stepping motor and has one end of its winding connected to each other. , third and fourth windings located electrically 90 degrees apart from the first and second windings and having one ends of the windings connected to each other, and one end of the windings connected to the first winding. first and second switching elements connected to the non-interconnected sides of the windings of the decoder, the other ends of which are connected to the power and ground sides, and the control inputs of which are connected to the output of the decoder; third and fourth switching elements connected to the connection point of the second winding, other ends connected to the power supply and ground side, and control inputs connected to the output of the decoder; and one end connected to the second winding. fifth and sixth switching elements connected to the non-interconnected side of the line, the other end being connected to the power supply and ground side and having a control input connected to the output of the decoder; and one end connected to the third winding. seventh and eighth switching elements connected to the non-interconnected side of the line, the other end being connected to the power supply and ground side and having a control input connected to the output of the decoder; 9th and 10th switching elements connected to the connection point of the fourth winding, other ends connected to the power supply and ground side, and control inputs connected to the output of the decoder; and one end connected to the fourth winding. an eleventh and a twelfth switching element connected to a non-interconnected side of the flexible disk, the other end being connected to the power supply and ground side, and having a control input connected to the output of the decoder. Device stepping motor drive circuit.