Telegraphy Patents (Class 178)
- Automatic (Class 178/3)
- Position coordinate determination for writing (e.g., writing digitizer pad, stylus, or circuitry) (Class 178/18.01)
- Stenographic (Class 178/21)
- Printing (Class 178/23R)
- Space induction (Class 178/43)
- Loaded circuit (Class 178/45)
- Harmonic or reed (Class 178/47)
- Superposed current (Class 178/49)
- Chemical (Class 178/62)
- Cable or capacity (Class 178/63R)
- Coil transformer (Class 178/64)
- Dynamo (Class 178/65)
- Alternating or pulsating current (Class 178/66.1)
- Line-clearing and circuit maintenance (Class 178/69R)
- Call (Class 178/69.6)
- Simplex-reversing periodic (Class 178/2A)
- Code changers (Class 178/2B)
- Way stations; party lines (Class 178/2C)
- Round robins (Class 178/2D)
- Satellite (Class 178/2E)
- Coin-controlled, connecting, recording (Class 178/2F)
- Automatic in either direction (Class 178/71.1)
- Relays only (Class 178/70A)
- Vibrating relays (Class 178/70B)
- Rotary distributors (Class 178/70C)
- Mechanical (Class 178/70D)
- Tuning forks (Class 178/70E)
- Vacuum tubes (Class 178/70F)
- Gas tubes (Class 178/70H)
- Magnetic (Class 178/70M)
- Magnetron repeaters (Class 178/70N)
- Photocell (Class 178/70P)
- Piezoelectric (Class 178/70Q)
- Generator (Class 178/70J)
- Having a carrier wave input (Class 178/70S)
- Oscillatory (Class 178/70T)
- Using transistors (Class 178/70TS)
