Apparatus for varying the speed of DC motors
First Claim
1. In an electric motor of the type having an armature with the rotor windings thereof electrically connected to a commutator, a set of brushes for applying current to the commutator segments, and the entire motor powered by a source of DC voltage, the improvement whereby:
- a. said commutator includes one dead commutator segment having a peripheral width dimension at least as great as the corresponding dimension of one of said brushes whereby as the dead segment leaves a brush, current is interrupted;
b. electronic switching means in the electrical circuit between said source and said commutator for maintaining said current interruption from the DC voltage source to the brushes until reactivation of said switching means; and
c. gating means for reactivating said electronic switching means after a variable predetermined time lag whereby the speed of said electric motor may be varied without a constant drain of power from the source of DC voltage.
0 Assignments
0 Petitions
Accused Products
Abstract
The commutator of a DC motor is uniquely constructed to include at least one dead segment at least as wide as the associated brush (brushes). A silicon controlled rectifier (SCR) is arrranged in the circuit between the voltage source and said brush (brushes) to provide a switching means to automatically cut off current flow therethrough each time a brush passes over the dead segment. The current is reestablished by way of a gating means, which in the preferred embodiment is a variable frequency pulse generator.
22 Citations
5 Claims
-
1. In an electric motor of the type having an armature with the rotor windings thereof electrically connected to a commutator, a set of brushes for applying current to the commutator segments, and the entire motor powered by a source of DC voltage, the improvement whereby:
-
a. said commutator includes one dead commutator segment having a peripheral width dimension at least as great as the corresponding dimension of one of said brushes whereby as the dead segment leaves a brush, current is interrupted; b. electronic switching means in the electrical circuit between said source and said commutator for maintaining said current interruption from the DC voltage source to the brushes until reactivation of said switching means; and c. gating means for reactivating said electronic switching means after a variable predetermined time lag whereby the speed of said electric motor may be varied without a constant drain of power from the source of DC voltage. - View Dependent Claims (2, 3, 4, 5)
-
Specification