摘要 |
The invention concerns a circuit for a load transfer switch comprising a regulating winding with a regulating stage (1) whose load current can be conducted via a lower or a higher winding tap (2, 3) and via at least two selector contacts (4, 5) and two permanent contacts (6, 7) with a common terminal lead (8). Switching from the lower to the higher winding tap or vice versa occurs via a first load transfer switch (9), wherein contact (10) is located in the connection of the selector contact (4) to the permanent contact (6) and the contact (11) is placed in the connection of the selector contact (5) to the permanent contact (7). The root contact of the first load transfer switch is connected via a transition resistor (13) and a bridging switch (14) in series to the common terminal lead (8). A second load transfer switch (15) is provided, wherein contact (16) is once again connected to the connection of the selector contact (4) to the permanent contact (6) and contact (17) is connected to the connection of selector contact (5) to permanent contact (7). The root contact (18) of said second load transfer switch (15) is connected to the connection of the transition resistor (13) and the bridging switch (14) by means of a thyristor circuit (19). The thyristor circuit (19) has antiparallel-connected thyristors. |