|  13/00  | Arrangements for influencing the relationship between signals at input and output, e.g. differentiating, delaying | 
|  13/02  | Arrangements for influencing the relationship between signals at input and output, e.g. differentiating, delaying to yield a signal which is a function of two or more signals, e.g. sum, product | 
|  15/00  | Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path | 
|  15/02  | Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path simultaneously, i.e. using frequency division | 
|  15/04  | Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path simultaneously, i.e. using frequency division the signals being modulated on carrier frequencies | 
|  15/06  | Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path successively, i.e. using time division | 
|  15/08  | Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path successively, i.e. using time division the signals being represented by amplitude of current or voltage in transmission link | 
|  15/10  | Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path successively, i.e. using time division the signals being represented by frequencies or phase of current or voltage in transmission link | 
|  15/12  | Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path successively, i.e. using time division the signals being represented by pulse characteristics in transmission link | 
|  17/00  | Arrangements for transmitting signals characterised by the use of a wireless electrical link | 
|  17/02  | Arrangements for transmitting signals characterised by the use of a wireless electrical link using a radio link | 
|  17/04  | Arrangements for transmitting signals characterised by the use of a wireless electrical link using magnetically coupled devices | 
|  17/06  | Arrangements for transmitting signals characterised by the use of a wireless electrical link using capacity coupling | 
|  19/00  | Electric signal transmission systems (G08C 17/00 takes precedence) | 
|  19/02  | Electric signal transmission systems (G08C 17/00 takes precedence) in which the signal transmitted is magnitude of current or voltage (G08C 19/36, G08C 19/38 take precedence) | 
|  19/04  | Electric signal transmission systems (G08C 17/00 takes precedence) in which the signal transmitted is magnitude of current or voltage (G08C 19/36, G08C 19/38 take precedence) using variable resistance | 
|  19/06  | Electric signal transmission systems (G08C 17/00 takes precedence) in which the signal transmitted is magnitude of current or voltage (G08C 19/36, G08C 19/38 take precedence) using variable inductance | 
|  19/08  | Electric signal transmission systems (G08C 17/00 takes precedence) in which the signal transmitted is magnitude of current or voltage (G08C 19/36, G08C 19/38 take precedence) using variable inductance differentially influencing two coils | 
|  19/10  | Electric signal transmission systems (G08C 17/00 takes precedence) in which the signal transmitted is magnitude of current or voltage (G08C 19/36, G08C 19/38 take precedence) using variable capacitance | 
|  19/12  | Electric signal transmission systems (G08C 17/00 takes precedence) in which the signal transmitted is frequency or phase of ac |