EP0102471A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Stepping motor driving circuit
Assignee: Toshiba Tec Corp
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Filing: 1983-06-30
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Granted: —
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Expires: 2003-06-30
Abstract
Abstract A stepping motor driving circuit includes a plurality of switching transistors (TR1 to TR4) having their emitter- collector paths connected to the corresponding ends of motor coils (L1 to L4), a plurality of diodes (D1 to D4) having their anodes connected to the above-mentioned ends of the motor coils (L1 to L4) and their cathodes connected to a common terminal, and a braking circuit (2) connected between the cathode of the diodes (D1 to D4) and the other end of the motor coils (L1 to L41, in which the switching transistors (TR1 to TR4) are sequentially turned ON to permit excitation currents to pass through the corresponding motor coils IL1 to L4). The braking circuit (2) has a variable effective impedance.
Inventors
- 👤 Tsuyoshi Matsushita
- 👤 Makoto Takahashi
- 👤 Kazuaki Takaishi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 23:50
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
147 words
A stepping motor driving circuit comprising: a plurality of switching means (TR1 to TR4) connected to first ends of a corresponding number of motor coils (Ll to L4) of a stepping motor to be driven; control means (4) for controlling the conduction states of said plurality of switching means (TRl to TR4) to permit excitation currents to sequentially pass through the motor coils (Ll to L4) over a predetermined period; a plurality of unidirectional circuit means (Dl to D4) connected at one end to said first ends of the corresponding number of the motor coils (Ll to L4) and connected at the other end to a common terminal; and braking means (2) connected between second ends of the motor coils (Ll to L4) and the other ends of the unidirectional circuit means (Dl to D4), characterized in that said braking means (2) has a variable effective impedance.
Claim 2
Dependent Claim
147 words
A stepping motor driving circuit comprising: a plurality of switching means (TR1 to TR4) connected to first ends of a corresponding number of motor coils (Ll to L4) of a stepping motor to be driven; control means (4) for controlling the conduction states of said plurality of switching means (TRl to TR4) to permit excitation currents to sequentially pass through the motor coils (Ll to L4) over a predetermined period; a plurality of unidirectional circuit means (Dl to D4) connected at one end to said first ends of the corresponding number of the motor coils (Ll to L4) and connected at the other end to a common terminal; and braking means (2) connected between second ends of the motor coils (Ll to L4) and the other ends of the unidirectional circuit means (Dl to D4), characterized in that said braking means (2) has a variable effective impedance.
Claim 3
Dependent Claim
44 words
A stepping motor driving circuit according to claim 1, characterized in that each of said switching means (TR1 to TR4) is a transistor whose emitter- collector path is connected in series with the corresponding one of said plurality of motor coils (Ll to L4).
Claim 4
Dependent Claim
41 words
A stepping motor driving circuit according to claim 1, characterized in that each of said unidirectional circuit means (Dl to D4) is a diode connected at one end to the corresponding one of said plurality of motor coils (Ll to L4).
Claim 5
Dependent Claim
90 words
A stepping motor driving circuit according to claim 3, characterized in that said braking means comprises a transistor (TR5) having its emitter- collector path connected between the other end of the motor coils (Ll to L4) and the anode of the diode (Dl to D4), resistor means (Rl) connected between the emitter and the base of said transistor (TR5), constant voltage means (D5) connected between the base and the collector of said transistor (TR5), and a switching circuit (TR6, D6, SW) connected in parallel with the constant voltage means (D5).
Claim 6
Dependent Claim
64 words
A stepping motor driving circuit according to claim 4, characterized in that said switching circuit comprises a phototransistor (TR6) having its emitter- collector path connected in parallel with said constant voltage means (D5), a light emitting diode (D6) for emitting light to the base of the phototransistor (TR6), and current supply means (SW) for selectively supplying a current to the light emitting diode (D6).
Claim 7
Dependent Claim
21 words
A stepping motor driving circuit according to claim 5, characterized in that said constant voltage means (D5) is a zener diode.
Claim 8
Dependent Claim
21 words
A stepping motor driving circuit according to claim 4, characterized in that said constant voltage means (D5) is a zener diode.
References Cited (Backward Citations)
No citation records indexed.
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