US3696277A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Start circuit for dc motor having a thyristor commutator
Assignee: Siemens AG
•
Filing: 1970-10-29
•
Granted: 1972-10-03
•
Expires: 1990-10-29
Abstract
Abstract When firing or ignition transformers are utilized in the firing or ignition circuit of an electronic commutator such as, for example, that utilized in the Siemotron drive, there is no ignition or firing pulse at the thyristors during the start of the motor due to the signal provided by the rotor position sensor. In order to insure a reliable start of the motor, additional firing pulses are periodically applied to the firing circuit. Upon the attainment of a specific speed, the additional pulses are automatically discontinued.
Inventors
- 👤 Manfred Liska
- 👤 Klaus Hubner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:04
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
144 words
A start circuit for a DC motor having a rotor, a thyristor commutator comprising a plurality of thyristors and firing circuit means coupled to the rotor of the motor and connected to said thyristors for conductively controlling said thyristors with control pulses in accordance with the position of the rotor of the motor, said firing circuit means including a plurality of firing transformers each connected to a corresponding one of said thyristors, a plurality of switching transistors each connected to a corresponding one of said firing transformers and control means coupled to the rotor of the motor and connected to the switching transistors for supplying control pulses to the switching transistors during a starting period, said start circuit comprising a pulse generator connected to the switching transistors of the firing circuits for providing additional control pulses for said switching transistors during the starting period.
Claim 2
Dependent Claim
144 words
A start circuit for a DC motor having a rotor, a thyristor commutator comprising a plurality of thyristors and firing circuit means coupled to the rotor of the motor and connected to said thyristors for conductively controlling said thyristors with control pulses in accordance with the position of the rotor of the motor, said firing circuit means including a plurality of firing transformers each connected to a corresponding one of said thyristors, a plurality of switching transistors each connected to a corresponding one of said firing transformers and control means coupled to the rotor of the motor and connected to the switching transistors for supplying control pulses to the switching transistors during a starting period, said start circuit comprising a pulse generator connected to the switching transistors of the firing circuits for providing additional control pulses for said switching transistors during the starting period.
Claim 3
Dependent Claim
88 words
A start circuit as claimed in claim 1, wherein each of the switching transistors of the firing circuit means has a control path and wherein said firing circuit means further comprises a plurality of input transistors each having a collector electrode connected to the control path of a corresponding one of said switching transistors and a base electrode connected to said pulse generator whereby the additional control pulses provided by said pulse generator are superimposed upon the control pulses supplied to the switching transistors via the input transistors.
Claim 4
Dependent Claim
57 words
A start circuit as claimed in claim 2, wherein the pulse generator comprises a switching transistor connected as the output stage thereof and connected in parallel to the collector electrode of each of said input transistors and the control path of each of said switching transistors is energized by the collector potential of the corresponding input transistor.
Claim 5
Dependent Claim
85 words
A start circuit as claimed in claim 2, wherein the pulse generator comprises a source of direct voltage, a charging capacitor and a resistor connected in series circuit arrangement with the charging capacitor to the source of direct voltage, a discharge current path connected to a common point in the connection between the charging capacitor and the resistor, and a switching transistor connected as the output stage of said pulse generator and connected in parallel to the collector electrode of each of said input transistors.
Claim 6
Dependent Claim
67 words
A start circuit as claimed in claim 2, wherein said pulse generator includes a switch for controlling the output of the additional control pulses and a limit circuit coupled to the rotor of the motor and controlling the operation of said switch for discontinuing the output of the additional control pulses from said pulse generator via said switch in accordance with the rotary speed of the motor.
Claim 7
Dependent Claim
32 words
A start circuit as claimed in claim 4, wherein the discharge current path of the pulse generator comprises a double base diode which is fired by the voltage of the charging capacitor.
Claim 8
Dependent Claim
88 words
A start circuit as claimed in claim 4, wherein each of the switching transistors has a base electrode and an emitter-collector path and wherein said firing circuit means further comprises a plurality of capacitors each connected between the collector electrode of a corresponding one of the input transistors and the base electrode of a corresponding one of the switching transistors, and a plurality of decoupling diodes each connected between the charging capacitor of the pulse generator and the emitter-collector path of a corresponding one of the switching transistors.
Claim 9
Dependent Claim
56 words
A start circuit as claimed in claim 5, further comprising a sine-cosine sensor having a pair of inputs coupled to the rotor of the motor and a pair of outputs and speed indicating means having inputs coupled to the outputs of the sine-cosine sensor and an output connected to the limit circuit of said pulse generator.
Claim 10
Dependent Claim
139 words
A start circuit as claimed in claim 8, wherein said speed indicating means comprises a first differenTiator having an input connected to one of said inputs, a first multiplier having an input connected in series circuit arrangement with the first differentiator, another input connected to another of said inputs and an output, a second differentiator having an input connected to the other of said inputs, a second multiplier having an input connected in series circuit arrangement with the second differentiator, another input connected to the first of said inputs and an output, and summing means having an output connected to the limit circuit of said pulse generator, an input connected to the output of the first multiplier and another input connected to the output of the second multiplier for subtractively combining output signals from said first and second multipliers.
Claim 11
Dependent Claim
65 words
A start circuit as claimed in claim 9, further comprising motor energizing means connected between the output of said speed indicating means and the thyristors of the thyristor commutator, said motor energizing means including rectifier means connected to said thyristors and a rectifier control unit connected to said rectifier means and having a synchronizing stage connected to said pulse generator for energizing said pulse generator.
References Cited (Backward Citations)
US2814769A
Cited
US3242406A
Cited
US3319104A
Cited
US3412303A
Cited
US3402337A
Cited
US3517289A
Cited
US3488566A
Cited
US3518516A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |