Patent US3757186A successfully refreshed from Google Patents.
US3757186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vernier chopper controlling device
Assignee: Hitachi Ltd
•
Filing: 1971-12-16
•
Granted: 1973-09-04
•
Expires: 1991-12-16
Abstract
Abstract The armature current of a D.C. electric motor is controlled for power control by selectively shunting a plurality of series starting resistances, in order, which have resistance values such that the armature current, upon shunting, changes in value from a fixed starting current minimum to a permissible current maximum for each starting resistance, in combination with means for assuring that each of these current changes will be smooth and continuous over a substantial period of time by changing an effective series connected resistance an amount substantially equal to the starting resistance to be shunted, for each of the starting resistances in the order of their shunting. This means includes a current chopper in parallel electrical connection with a control resistance. The chopper may operate to pass current over a range identical for each shunting with variation of the control resistance to match the starting resistance to be shunted, or the control resistance may be identical for each shunting and the chopper current range may be matched to each of the resistances to be shunted.
Inventors
- 👤 T Ozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:15
CPC Classifications
B; B60; B60L; B60L9/00; H; H02; H02P; H02P1/00; H02P1/16; H02P1/18; H02P1/20; B60L2200/00; B60L2200/26; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/917; Y10S388/92
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
139 words
A direct current rotary electric machine control circuit, comprising: a plurality of separate starting resistances in series and having different resistance values; means for placing said starting resistances in series with a source of electric power and a rotary D.C. electric machine for stepping power control; means for shunting each of said starting resistances in a predetermined order so that the thus controlled current minimum and maximum for each successive shunting remains respectively constant as determined by the different starting resistance values; current chopper and resistance means in series with said starting resistances for changing in effective resistance smoothly over a period of time immediately prior to shunting each starting resistance, with the resistance change being different for each shunting and matched with the starting resistance to be shunted, and substantially instantaneously adding the same effective resistance at shunting.
Claim 2
Dependent Claim
139 words
A direct current rotary electric machine control circuit, comprising: a plurality of separate starting resistances in series and having different resistance values; means for placing said starting resistances in series with a source of electric power and a rotary D.C. electric machine for stepping power control; means for shunting each of said starting resistances in a predetermined order so that the thus controlled current minimum and maximum for each successive shunting remains respectively constant as determined by the different starting resistance values; current chopper and resistance means in series with said starting resistances for changing in effective resistance smoothly over a period of time immediately prior to shunting each starting resistance, with the resistance change being different for each shunting and matched with the starting resistance to be shunted, and substantially instantaneously adding the same effective resistance at shunting.
Claim 3
Dependent Claim
65 words
The control circuit of claim 1, wherein said current chopper and resistance means includes at least one control resistance means in series with said separate starting resistances and having a resistance value at least as great as the greatest resistance value of said starting resistances, and further having a current chopper in parallel with said control resistance means and in series with said starting resistances.
Claim 4
Dependent Claim
50 words
The control circuit of claim 2, wherein said current chopper and resistance means controls the operation of said current chopper to vary the current passed therethrough in a continuous manner from a predetermined minimum to a predetermined maximum constituting a range, with the range for each shunting step being different.
Claim 5
Dependent Claim
79 words
The control circuit of claim 3, wherein said current chopper and resistance means controls the operation of said current chopper so that the first chopper range will effectively reduce the resistance of said control resistance means in series with said starting resistances an amount equal to the resistance of the first starting resistance shunted, and the second chopper range will effectively reduce the resistance of said control resistance means an amount substantially equal to the second starting resistance shunted.
Claim 6
Dependent Claim
49 words
The control circuit of claim 1, wherein said current chopper and resistance means includes a selectively variable resistance means in parallel with a fixed range current chopper and means for varying the variable resistance means to successively match each of said starting resistances, in order, as they are shunted.
Claim 7
Dependent Claim
49 words
The control circuit of claim 5, wherein said variable resistance means and means for varying include a plurality of separate resistances in parallel with each other and in parallel with said current chopper and switch means for connecting and disconnecting at least some of said parallel resistances in circuit.
Claim 8
Dependent Claim
64 words
The control circuit of claim 6, in combination with a direct current rotary electric machine having an armature in series connection with said starting resistances, and in series connection with said current chopper and resistance means; said armature having a maximum permissible current level equal to said maximum current; and said armature further having a designed starting current equal to said minimum current level.
Claim 9
Dependent Claim
64 words
The control circuit of claim 4, in combination with a direct current rotary electric machine having an armature in series connection with said starting resistances, and in series connection with said current chopper and resistance means; said armature having a maximum permissible current level equal to said maximum current; and said armature further having a designed starting current equal to said minimum current level.
Claim 10
Dependent Claim
64 words
The control circuit of claim 1, in combination with a direct current rotary electric machine having an armature in series connection with said starting resistances, and in series connection with said current chopper and resistance means; said armature having a maximum permissible current level equal to said maximum current; and said armature further having a designed starting current equal to said minimum current level.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |