| 1/00 | Circuit arrangements for dc mains or dc distribution networks |
| 1/02 | Circuit arrangements for dc mains or dc distribution networks Arrangements for reducing harmonics or ripples (in converters H02M 1/14) |
| 1/04 | Circuit arrangements for dc mains or dc distribution networks Constant-current supply systems |
| 1/06 | Circuit arrangements for dc mains or dc distribution networks Two-wire systems |
| 1/08 | Circuit arrangements for dc mains or dc distribution networks Three-wire systems; Systems having more than three wires |
| 1/10 | Circuit arrangements for dc mains or dc distribution networks Parallel operation of dc sources (involving batteries H02J 7/34) |
| 1/12 | Circuit arrangements for dc mains or dc distribution networks Parallel operation of dc sources (involving batteries H02J 7/34) Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier |
| 1/14 | Circuit arrangements for dc mains or dc distribution networks Balancing the load in a network (by batteries H02J 7/34) |
| 1/16 | Circuit arrangements for dc mains or dc distribution networks Balancing the load in a network (by batteries H02J 7/34) using dynamo-electric machines coupled to flywheels |
| 3/00 | Circuit arrangements for ac mains or ac distribution networks |
| 3/01 | Circuit arrangements for ac mains or ac distribution networks Arrangements for reducing harmonics or ripples (in converters H02M 1/12) |
| 3/02 | Circuit arrangements for ac mains or ac distribution networks using a single network for simultaneous distribution of power at different frequencies; using a single network for simultaneous distribution of ac power and of dc power |
| 3/04 | Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources |
| 3/06 | Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources Controlling transfer of power between connected networks; Controlling sharing of load between connected networks |
| 3/08 | Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources Synchronising of networks |
| 3/10 | Circuit arrangements for ac mains or ac distribution networks Constant-current supply systems |
| 3/12 | Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load |
| 3/14 | Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by switching loads on to, or off from, network, e.g. progressively balanced loading |
| 3/16 | Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by adjustment of reactive power |
| 3/18 | Circuit arrangements for ac mains or ac distribution networks Arrangements for adjusting, eliminating, or compensating reactive power in networks (for adjustment of voltage H02J 3/12; use of Petersen coils H02H 9/08) |