| 摘要 |
PURPOSE: A control card for a signal device is provided to prevent a rear device by connecting an SSR(Solid State Relay) to a rear part of a relay which is connected and receives a current, and then making the relay a short circuit when inputting an overcurrent and a rush current. CONSTITUTION: A driving signal output terminal of a decoder(24) is connected to an input terminal(IN2) of a solid state relay. A power source is connected in parallel to a driving terminal(DR1) of the solid state relay through a varistor. A current sensor(29a) is interposed between a driving terminal(DR2) and a railway signal instrument(12a). A detection circuit(32a) is connected to the other terminal of a current sensor. The detection circuit supplies a detection signal to the solid state relay. |
