| 摘要 |
PURPOSE:To confirm easily the on-off operation of each switch of an input equipment with a diode matrix by conneting series circuits of signal input switches and LEDs between input signal lines near respective intersections and plural earth lines. CONSTITUTION:Control circuit 8 generates a control signal for a circuit to be controlled; input signal lines IN1-IN4 are connected to circuit 8 and earth lines G1 and G2 are held at the earth level with transistor Trs 9 and 10 turned on. Then, series circuits of signal switches S1-S8, and LEDs LD1-LD8 are connected between input signal lines IN1-IN4 near respective intersections and earth lines G1 and G2. Consequently, when switch S1, for example, is closed, LED LD1 is fed with a current with its input signal connected correctly to turn on, so that the on-off operations of respective switches S1-S8 can be confirmed easily. |
