| Class Number |
Class Name |
No. of Patents |
| 388/842 |
Closed loop acceleration control system for dc motor with commutator |
8 |
| 388/844 |
Armature control |
6 |
| 388/847 |
By voltage or current modification |
21 |
| 388/843 |
Field control, or field and armature control |
11 |
| 388/800 |
Closed loop speed control system for dc motor with commutator |
126 |
| 388/816 |
Analog armature control |
57 |
| 388/823 |
By current modification |
60 |
| 388/820 |
By phase or frequency modification |
77 |
| 388/819 |
By pulse width or duty cycle modification |
96 |
| 388/824 |
By variable impedance (e.g., potentiometer) |
24 |
| 388/821 |
By voltage and current modification |
57 |
| 388/822 |
By voltage modification |
62 |
| 388/809 |
Armature control by digital or combined analog and digital circuitry |
105 |
| 388/814 |
By frequency modification |
134 |
| 388/812 |
By phase and frequency modification |
97 |
| 388/813 |
By phase modification |
95 |
| 388/811 |
By pulse width or duty cycle modification |
367 |
| 388/815 |
By voltage or current modification |
223 |
| 388/803 |
Field control, or field and armature control, by analog (only) circuitry |
43 |
| 388/805 |
By phase or frequency modification |
40 |
| 388/804 |
By pulse width or duty cycle modification |
107 |
| 388/808 |
By selection of windings |
4 |
| 388/806 |
By voltage or current modification |
115 |
| 388/807 |
With variable impedance |
10 |
| 388/801 |
Field control, or field and armature control, by digital or combined analog and digital circuitry |
64 |
| 388/848 |
Open loop acceleration control system for dc motor with commutator |
3 |
| 388/853 |
Armature control |
2 |
| 388/855 |
By selectable or variable impedance |
2 |
| 388/856 |
By insertion of resistance or shorting of circuit |
2 |
| 388/859 |
With patterned switch |
0 |
| 388/857 |
With relay |
1 |
| 388/858 |
Time delay relay |
1 |
| 388/860 |
Manual |
6 |
| 388/854 |
By voltage or current modification |
7 |
| 388/849 |
Field control, or field and armature control |
4 |
| 388/852 |
By insertion of resistance |
0 |
| 388/851 |
By patterned switch |
1 |
| 388/850 |
By transformer or inductive device |
0 |
| 388/825 |
Open loop speed control system for dc motor with commutator |
22 |
| 388/830 |
Analog armature control |
23 |
| 388/835 |
By control of motor structure |
9 |
| 388/836 |
Position or number of brushes |
21 |
| 388/832 |
By frequency modification |
21 |
| 388/837 |
By periodic mechanical switch |
5 |
| 388/831 |
By pulse width or duty cycle modification |
71 |
| 388/834 |
By selection of windings |
4 |
| 388/833 |
By voltage or current modification |
32 |
| 388/838 |
With plural selectable speeds (e.g., with manual switch, potentiometer |
52 |
| 388/839 |
By selecting impedance |
10 |
| 388/841 |
Inductive |
1 |
| 388/840 |
Resistive |
32 |
| 388/828 |
Armature control by digital or combined analog and digital circuitry |
22 |
| 388/829 |
By pulse width or duty cycle modification |
51 |
| 388/826 |
Field control, or field and armature control |
12 |
| 388/827 |
With plural selectable speeds (e.g., manual switch) |
18 |
| 388/935 |
Specific application: |
4 |
| 388/936 |
Food preparation equipment |
12 |
| 388/937 |
Hand tool |
108 |
| 388/907 |
Specific control circuit element or device |
35 |
| 388/907.2 |
Bridge circuit |
57 |
| 388/907.5 |
Computer or microprocessor |
260 |
| 388/908 |
Frequency to voltage converter |
31 |
| 388/909 |
Monitoring means |
78 |
| 388/910 |
Operational/differential amplifier |
131 |
| 388/911 |
Phase locked loop |
88 |
| 388/912 |
Pulse or frequency counter |
200 |
| 388/913 |
Saturable reactor, space discharge device, or magnetic amplifier |
1 |
| 388/914 |
Thyratron or ignitron |
0 |
| 388/915 |
Sawtooth or ramp waveform generator |
142 |
| 388/916 |
Threshold circuit |
43 |
| 388/917 |
Thyristor or scr |
160 |
| 388/920 |
Chopper |
50 |
| 388/918 |
Trigger by unijunction transistor |
9 |
| 388/919 |
Triggered by resistor or capacitor |
31 |
| 388/921 |
Timer or time delay means |
114 |
| 388/922 |
Tuned or resonant circuit |
25 |
| 388/923 |
Specific feedback condition or device |
16 |
| 388/924 |
Centrifugal device (e.g., governor) |
5 |
| 388/925 |
Including contacts which open and close motor circuit |
4 |
| 388/926 |
Which controls a vacuum tube or solid-state device in motor circuit |
1 |
| 388/928 |
Which controls position of commutator brushes |
4 |
| 388/927 |
Which varies resistance of motor circuit |
0 |
| 388/928.1 |
Counter or back emf (cemf) |
121 |
| 388/929 |
Fluid/granular material flow rate, pressure, or level |
29 |
| 388/930 |
Load or torque |
117 |
| 388/931 |
Electric generator or magnet as auxiliary load |
4 |
| 388/932 |
With reverse torque (e.g., braking) |
9 |
| 388/933 |
Radiant energy responsive device |
66 |
| 388/934 |
Thermal condition |
161 |
| 388/900 |
Specific system operational feature |
39 |
| 388/905 |
Armature and field windings connected in series (i.e., series motor) |
6 |
| 388/902 |
Compensation |
171 |
| 388/906 |
Proportional-integral system |
58 |
| 388/903 |
Protective (e.g., voltage or current limit) |
221 |
| 388/901 |
Sample and hold |
74 |
| 388/904 |
Stored velocity profile |
63 |
