| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power unit insensitive to a load formed so as to allow a two-way current to flow in each of a first/second series circuit independently of the change of the level of the load. SOLUTION: An electric power unit 100 insensitive to a load includes an output circuit 142 normally connected to a load receiving power from a power source and an input circuit connected to both ends of an AC power source alternately having a first/second 180 deg. half cycle of action. Having a primary winding 114 connected to both ends of this input circuit, having a common connection part 122, a transformer 112 including a first/second series connection secondary winding is provided. Between this connection part and the output circuit 142, a filter choke 140 is connected in series. In a first two-way switch 152, at on time, a first secondary winding 118 and the output circuit 142 in the filter choke 140 and a first series circuit are connected, a two-way current is allowed to flow in these winding and circuit. In a second two-way switch, at on time, a second secondary winging 120 and the output circuit 142 in the filter choke 140 and a second series circuit are connected, a two-way current is allowed to flow in these winding and circuits. |
