Abstract A circuit for a direct current motor of which the armature is fed, during the driving action of the motor, through the intermediary of a driving thyristor provided with a thyristor extinguishing means, the armature being connected during braking of the motor, through a series connected load resistance and a braking thyristor provided with means for extinguishing the braking thyristor, the extinguishing means comprising a switching inductance and a switching condenser, and a circuit connected in anti-parallel of an extinguishing thyristor and a diode for recharging the switching condenser; the switching condenser has a first terminal connected to a terminal of the motor which is common to the driving thyristor and the braking thyristor, and a second terminal common to the anti-parallel circuit of the means for extinguishing the driving thyristor and to that for extinguishing the braking thyristor, the circuits being so connected that such one switching condenser serves both thyristor extinguishing means.
In an intermittent switching circuit for a DC motor: first switching means including a first normally unoperated thyristor in series with the motor armature; a load resistance; second switching means including a second normally unoperated thyristor serially interconnecting the armature and the load resistance; third and fourth normally unoperated thyristors; a common capacitor for coupling the third thyristor across the first switching means and for coupling the fourth thyristor across the second switching means; first and second rectifiers; first means for coupling the first rectifier across the third thyristor with their respective transconductive paths being oppositely directed; and second means for coupling the second rectifier across the fourth thyristor with their respective transconductive paths being oppositely directed.
Claim 2
Dependent Claim
117 words
In an intermittent switching circuit for a DC motor: first switching means including a first normally unoperated thyristor in series with the motor armature; a load resistance; second switching means including a second normally unoperated thyristor serially interconnecting the armature and the load resistance; third and fourth normally unoperated thyristors; a common capacitor for coupling the third thyristor across the first switching means and for coupling the fourth thyristor across the second switching means; first and second rectifiers; first means for coupling the first rectifier across the third thyristor with their respective transconductive paths being oppositely directed; and second means for coupling the second rectifier across the fourth thyristor with their respective transconductive paths being oppositely directed.
Claim 3
Dependent Claim
16 words
A circuit as defined in claim 1, in which the second coupling means comprises an inductance.
Claim 4
Dependent Claim
23 words
A circuit as defined in claim 1, in which the first switching means further comprises an inductance in series with the first thyristor.