A.c. induction motor speed control systems

Claim 2

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having at least a first and a second winding, b. a source of A.C. power having at least a first and second phase of voltage, c. said source of A.C. power having its first phase connected directly to said first winding, d. means for inserting a controlled D.C. component into the second winding of the motor to cause dynamic braking, which means includes: 1. a rectifier connecting said second phase to said second winding, 2. a controlled rectifying means connected across said rectifier, 3. controlling means connected to said controlled rectifying means for continuously varying the rectification of said controlled rectifying means.

Claim 3

a controlled rectifying means connected across said rectifier,

Claim 4

a controlled rectifying means connected across said rectifier,

Claim 5

A combination as in claim 1 wherein said motor is a three-phase squirrel-cage motor having three windings and said source of power is a three phase source, with two of said phases connecting directly to two of said windings.

Claim 6

A combination as in claim 2 wherein said controlling means includes a tachometer generator coupled to said motor.

Claim 7

controlling means connected to said controlled rectifying means for continuously varying the rectification of said controlled rectifying means.

Claim 8

controlling means connected to said controlled rectifying means for continuously varying the rectification of said controlled rectifying means.

Claim 9

A combination as in claim 1 wherein said controlled rectifying means is a silicon controlled rectifier.

Claim 10

A combination as in claim 4 wherein the gate of said silicon controlled rectifier is connected to a potentiometer which is coupled across two of the phases of said source of A.C. power.

Claim 11

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having at least a first and second winding, b. a source of A.C. power having at least a first and second phase of voltage, c. said first phase being connected directly to said first winding, d. a rectifier connecting said second phase to said second winding, e. a controlled rectifying means connected across said second winding, f. controlling means connected to said controlled rectifying means for continuously varying the rectification of said controlled rectifying means.

Claim 12

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having at least a first and second winding, b. a source of A.C. power having at least a first and second phase of voltage, c. said first phase being connected directly to said first winding, d. a rectifier connecting said second phase to said second winding, e. a controlled rectifying means connected across said second winding, f. controlling means connected to said controlled rectifying means for continuously varying the rectification of said controlled rectifying means.

Claim 13

A combination as in claim 6 wherein said motor is a three-phase squirrel-cage motor having three windings and said source of power is a three phase source, with two of said phases connecting directly to two of said windings.

Claim 14

A combination as in claim 6 wherein said controlled rectifying means is a silicon controlled rectifier.

Claim 15

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having at least a first and a second winding and a squirrel cage rotor, b. a source of A.C. power having at least a first and a second phase of voltage, c. said source of A.C. power being coupled to said windings, d. said second winding having connections at a centertap as well as at the first and second end of said winding, e. a first controlled rectifying means connected from said center-tap to said first end of said second winding and a second controlled rectifying means connected from said centertap to said second end of said second winding, f. controlling means connected to said first and second controlled rectifying means for continuously varying the rectification of said rectifying means.

Claim 16

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having at least a first and a second winding and a squirrel cage rotor, b. a source of A.C. power having at least a first and a second phase of voltage, c. said source of A.C. power being coupled to said windings, d. said second winding having connections at a centertap as well as at the first and second end of said winding, e. a first controlled rectifying means connected from said center-tap to said first end of said second winding and a second controlled rectifying means connected from said centertap to said second end of said second winding, f. controlling means connected to said first and second controlled rectifying means for continuously varying the rectification of said rectifying means.

Claim 17

A combination as in claim 9 wherein said motor has three windings and said source of power is a three phase source.

Claim 18

A combination as in claim 9 wherein said controlled rectifying means is a silicon controlled rectifier.

Claim 19

A combination as in claim 9 wherein said windings connect directly to said A.C. power source.

Claim 20

A combination as in claim 9 wherein one of said windings couples to one of said phases through a fan motor winding in a fan motor usEd to cool the windings of said A.C. induction motor.

Claim 21

A combination as in claim 13 wherein said A.C. induction motor has three windings and said source of power is a three phase source.

Claim 22

A combination as in claim 14 wherein said fan motor has three windings and each of which is in series with one of the connections from said source of power to said A.C. induction motor.

Claim 23

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having at least a first and a second winding, b. a source of A.C. power having at least a first and a second phase, c. said source of A.C. power being connected to said first winding and coupled to said second winding, d. said second winding being made of two partial windings which are separate in said motor, e. the first end of each of said partial windings being connected to each other, f. the second end of each of said partial windings being connected to a controlled rectifying means, there being one controlled rectifying means for each of the two partial windings, and g. means for continuously varying the rectification of said controlled rectifying means whereby a D.C. component can be controlled in each of the partial windings without introducing a D.C. component into said source of A.C. power.

Claim 24

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having at least a first and a second winding, b. a source of A.C. power having at least a first and a second phase, c. said source of A.C. power being connected to said first winding and coupled to said second winding, d. said second winding being made of two partial windings which are separate in said motor, e. the first end of each of said partial windings being connected to each other, f. the second end of each of said partial windings being connected to a controlled rectifying means, there being one controlled rectifying means for each of the two partial windings, and g. means for continuously varying the rectification of said controlled rectifying means whereby a D.C. component can be controlled in each of the partial windings without introducing a D.C. component into said source of A.C. power.

Claim 25

A combination as in claim 1 in which said A.C. induction motor has 3 windings, two of which connect directly to said power source; and said controlled rectifying means is an SCR.

Claim 26

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having three windings each of which has two partial windings which are separate and are wired in series, b. a source of A.C. power having three phases, each of said phases connecting to one of said windings, c. two controlled rectifiers connecting from the point of connection of the partial windings in one of the windings to the point of connection of the partial windings in each of the other two windings, d. means for continuously varying the rectification of said controlled rectifiers.

Claim 27

In combination in a control arrangement for continuously varying the speed of a motor: a. an A.C. induction motor having three windings each of which has two partial windings which are separate and are wired in series, b. a source of A.C. power having three phases, each of said phases connecting to one of said windings, c. two controlled rectifiers connecting from the point of connection of the partial windings in one of the windings to the point of connection of the partial windings in each of the other two windings, d. means for continuously varying the rectification of said controlled rectifiers.