EP0311355A2
Expired / Lapsed
EP
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Electric motor controllers
Assignee: Chloride Group Ltd
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Filing: 1988-10-04
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Granted: —
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Expires: 2008-10-04
Abstract
Abstract An electric motor controller comprises a circuit for selecting between driving and braking an electric motor in accordance with the health or otherwise of a pair of main electric motor control switches (14 and 16). In a preferred embodiment the health of the switch is determined by the voltage (A) between the switches. The controller also comprises means for detecting the sense of movement of the motor. In the event that the motor is moving in a sense opposite to that selected, the means increase field current to reduce the armature current thereby increasing the braking effect of the motor. Also in the controller are means for changing from armature to field current control and vice versa, in response to a given magnitude of control signal. In order to provide an unambiguous change-over, a lockout circuit is provided to inhibit change-over in a transition region. The lockout circuit maintains the mode of control to above/beneath the change-over level when changing from one level to another. The controller has a drive circuit which uses a flywheel inductor to provide an enhanced actuating signal for a transistor control switch for the motor. In a first state, the inductor is connected to by-pass the transistor to build-up a flywheel current. In a second state, the flywheel current is arranged to be applied to the transistor as a spike input.
Inventors
- 👤 Dennis Malcolm Jones
- 👤 Christopher Alan Harrington
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 11:21
CPC Classifications
B; B60; B60L; B60L15/00; B60L15/20; B60L15/28; H; H02; H02H; H02H7/00; H02H7/08; H02H7/0833; H02H7/0838; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/298; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/64; Y02T10/72
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
50 words
An electric load controller comprising first switch means (14,16) selectively operable in response to a control signal to control the load (11) and switch test means (32) connected to monitor the condition of the first switch means and arranged to inhibit the controller if the first switch means are faulty.
Claim 2
Dependent Claim
50 words
An electric load controller comprising first switch means (14,16) selectively operable in response to a control signal to control the load (11) and switch test means (32) connected to monitor the condition of the first switch means and arranged to inhibit the controller if the first switch means are faulty.
Claim 3
Dependent Claim
48 words
A controller as claimed in claim 1 in which second switch means (16, 14) are connected in series with the first switch means (14, 16), each of which switch means are selectively operable, in response to the control signal, to control the load for electrical driving and/or braking.
Claim 4
Dependent Claim
19 words
A controller as claimed in claim 2 in which the first and second switch means are connected in series.
Claim 5
Dependent Claim
29 words
A controller as claimed in claim 1,2 or 3 inwhich the switch test means (32) are operable in response to the voltage between the switch means (14 and 16).
Claim 6
Dependent Claim
27 words
A controller as claimed in claim 4 in which the switch test means (32) are arranged to inhibit the controller if the voltage falls outside specified limits.
Claim 7
Dependent Claim
26 words
A controller as claimed in claim 5 in which the said specified limits are 40% and 60% of the voltage across the or both switch means.
Claim 8
Dependent Claim
34 words
A controller as claimed in claim 4 or 5 in which by-pass means (15,17) are connected across the or each switch (14,16) from which the voltage across the or each switch means is derivable.
Claim 9
Dependent Claim
25 words
A controller as claimed in claim 1, 2 or 3 in which the switch test means (32) are operable in response to a current signal.
Claim 10
Dependent Claim
26 words
A controller as claimed in claim 8 in which the switch test means (32) are responsive to excessive leakage current in the or either switch means.
Claim 11
Dependent Claim
47 words
A controller as claimed in any of the preceding claims in which further test means (32) are connected across the or both switch means (14,16), the further test means being responsive to inhibit start-up of the load (11) if the voltage thereacross is below a predetermined value.
Claim 12
Dependent Claim
53 words
An electric motor controller comprising detecting means (106) arranged to detect when the motor is moving in a direction opposite to that selected, and electric motor field control means (28) arranged to operate in response to an output of the detecting means to vary the field current to tend to enhance electrical braking.
Claim 13
Dependent Claim
53 words
An electric motor controller comprising detecting means (106) arranged to detect when the motor is moving in a direction opposite to that selected, and electric motor field control means (28) arranged to operate in response to an output of the detecting means to vary the field current to tend to enhance electrical braking.
Claim 14
Dependent Claim
95 words
An electric motor controller arranged to operate in a first mode variably to control armature current of an electric motor by varying armature voltage and in a second mode variably to control the armature current by varying field current, the controller comprising means (25) arranged to produce a control signal representative of an input demand signal, change-over means (88) arranged to operate in response to the control signal to change between modes, and offset means (88) arranged to apply an offset biasing signal to the control signal when the controller is in a given mode.
Claim 15
Dependent Claim
95 words
An electric motor controller arranged to operate in a first mode variably to control armature current of an electric motor by varying armature voltage and in a second mode variably to control the armature current by varying field current, the controller comprising means (25) arranged to produce a control signal representative of an input demand signal, change-over means (88) arranged to operate in response to the control signal to change between modes, and offset means (88) arranged to apply an offset biasing signal to the control signal when the controller is in a given mode.
Claim 16
Dependent Claim
98 words
An electric motor controller comprising first switch means (14) selectively operable in response to a drive control signal from drive control means (26) to control a motor for driving; second switch means (16) selectively operable in response to a braking control signal from brake control means (26) to control the motor for braking; and lockout means (78 and 82), responsive to a lockout signal representative of the drive control and braking control signals, arranged selectively to inhibit the first switch means (14) or the second switch means (16) according as the motor is respectively braking or being driven.
Claim 17
Dependent Claim
98 words
An electric motor controller comprising first switch means (14) selectively operable in response to a drive control signal from drive control means (26) to control a motor for driving; second switch means (16) selectively operable in response to a braking control signal from brake control means (26) to control the motor for braking; and lockout means (78 and 82), responsive to a lockout signal representative of the drive control and braking control signals, arranged selectively to inhibit the first switch means (14) or the second switch means (16) according as the motor is respectively braking or being driven.
Claim 18
Dependent Claim
57 words
A drive circuit for electronic switch means (14,16,18) comprising a flywheel inductor (L1H, L1J, L1K) arranged, when the electronic switch means are in a first state, to carry a flywheel current and flywheel current switch means (BUZ72H, IRFD110J, IRFD110K) arranged to divert the path of inductor current thereby switching the electronic switch means to a second state.
Claim 19
Dependent Claim
57 words
A drive circuit for electronic switch means (14,16,18) comprising a flywheel inductor (L1H, L1J, L1K) arranged, when the electronic switch means are in a first state, to carry a flywheel current and flywheel current switch means (BUZ72H, IRFD110J, IRFD110K) arranged to divert the path of inductor current thereby switching the electronic switch means to a second state.
References Cited (Backward Citations)
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