EP0735666A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Control circuit for controlling the driving of a dc motor
Assignee: Ichikoh Industries Ltd
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Filing: 1996-03-29
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Granted: —
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Expires: 2016-03-29
Abstract
Abstract When a switch 12 is turned on, a relay coil 14b is excited by a current generated at the very moment when electric power of a dc power source 11 is supplied to a condenser 16 for actuation. Accordingly, a relay contact 14a is closed, and the power is given to a dc motor 15 via the switch 12 and the relay contact 14a. As a result, the dc motor 15 is actuated. At the same time, a part of a current running through the dc motor 15 is supplied to the relay coil 14b and brings about self-hold by which the dc motor 15 remains running. After that, when the driving of a device to be driven is forcibly regulated, an excess current passing through the dc motor 15 flows to a PTC thermistor (positive temperature coefficient thermistor) 13 which is connected in series to the dc motor 15. Owing to the excess current, the temperature of the PTC thermistor 13 is raised, and thereby the resistance of the PTC thermistor 13 is heightened. As a result, the relay contact 14a is opened to stop the dc motor 15. In a motor control circuit thus constructed, in order to prevent chattering which occurs when the dc motor 15 is operated to stop, and prevent the delay of the stop of the dc motor 15 and, additionally, lengthen the service life of the relay contact 14a, the PTC thermistor 13 is disposed to be in parallel with the condenser 16 with respect to the dc power source 11.
Inventors
- 👤 Kazuyasu Hayashi
- 👤 Hisaki Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 13:12
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; B; B60; B60R; B60R1/00; B60R1/02; B60R1/06; B60R1/062; B60R1/07; B60R1/074; H02H; H02H7/00; H02H7/08; H02H7/085; H02H7/0851; H02P7/03; H02H3/00; H02H3/02; H02H3/025; H02H9/00; H02H9/02; H02H9/026
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
304 words
A control circuit for controlling the driving of a direct-current motor, comprising: a dc electric power source; a dc motor for driving a thing to be driven, a power terminal of said dc motor being connected to an electrode of said dc electric power source at least via a relay contact and a control switch, the other power terminal of said dc motor being connected to the other electrode of said dc electric power source; a relay coil an end of which is connected to a point between said control switch and said relay contact via a condenser for startup and the other end is connected to the other power terminal of said dc motor, a relay being made up of said relay coil and said relay contact; a resistance for relay self-hold, an end of said resistance being connected to a point between said relay contact and said dc motor, the other end of said resistance being connected to a point between said condenser for startup and said relay coil; and a positive temperature coefficient thermistor disposed in a current path leading to said dc motor, said positive temperature coefficient thermistor raising its temperature and heightening its resistance because of an excess current generated when said thing being driven by said dc motor is physically stopped by a stopping member so that said dc motor becomes a state of overload, the resultant high resistance of said positive temperature coefficient thermistor lessening a current running through said relay coil which is performing self-hold, thereby opening said relay contact so as to stop said dc motor; wherein an end of said positive temperature coefficient thermistor is connected to a point between said control switch and said condenser for startup, and the other end of said positive temperature coefficient thermistor is connected to said relay contact.
Claim 2
Dependent Claim
305 words
A control circuit for controlling the driving of a direct-current motor, comprising: a dc electric power source; a dc motor for driving a thing to be driven, a power terminal of said dc motor being connected to an electrode of said dc electric power source at least via a relay contact and a control switch, the other power terminal of said dc motor being connected to the other electrode of said dc electric power source; a relay coil an end of which is connected to a point between said control switch and said relay contact via a condenser for startup and the other end is connected to the other power terminal of said dc motor, a relay being made up of said relay coil and said relay contact; a resistance for relay self-hold, an end of said resistance being connected to a point between said relay contact and said dc motor, the other end of said resistance being connected to a point between said condenser for startup and said relay coil; and a positive temperature coefficient thermistor disposed in a current path leading to said dc motor, said positive temperature coefficient thermistor raising its temperature and heightening its resistance because of an excess current generated when said thing being driven by said dc motor is physically stopped by a stopping member so that said dc motor becomes a state of overload, the resultant high resistance of said positive temperature coefficient thermistor lessening a current running through said relay coil which is performing self-hold, thereby opening said relay contact so as to stop said dc motor; wherein an end of said positive temperature coefficient thermistor is connected to a point between said dc motor and said resistance for relay self-hold, and the other end of said positive temperature coefficient thermistor is connected to said relay contact.
Claim 3
Dependent Claim
31 words
The control circuit of claim 1, further comprising a discharge resistance for causing said condenser for startup to discharge, said discharge resistance being connected in parallel to said condenser for startup.
Claim 4
Dependent Claim
114 words
The control circuit of claim 1, wherein said relay contact comprises a single movable contact connected to said dc motor, a normally-closed fixed contact with which said movable contact is brought into contact when said relay coil is not excited, and a normally-opened fixed contact with which said movable contact is brought into contact when said relay coil is excited; said positive temperature coefficient thermistor is disposed between said normally-opened fixed contact and a point between said control switch and said condenser for startup; and between said normally-closed fixed contact and a point between said control switch and said condenser for startup, a resistance for causing said condenser for startup to discharge is disposed.
Claim 5
Dependent Claim
41 words
The control circuit of claim 1, further comprising a discharge resistance for causing said condenser for startup to discharge, said discharge resistance being connected in parallel to a direct connection which consists of said condenser for startup and said relay coil.
Claim 6
Dependent Claim
61 words
The control circuit of claim 1, further comprising a discharge resistance for causing said condenser for startup to discharge, an end of said discharge resistance being connected to a point between said positive temperature coefficient thermistor and said relay contact, the other end of said discharge resistance being connected to a point between said condenser for startup and said relay coil.
References Cited (Backward Citations)
No citation records indexed.
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