| 摘要 |
This switching device ensures that the high/low tone sequence of audible signal devices is inhibited when the optical switching means (B 1, B 2), for example a beacon light, does not light up, which can be detected by means of at least one monitoring lamp (K 1, K 2). In each case the coil (6a, 9a) of a relay whose contact (6, 9) bypasses the series resistor (4, 7) of the monitoring lamp (K 1, K 2) is connected in series with the optical switching means (B 1, B 2). A transistor (1) is connected with its emitter-collector line (EC) on the one hand to the positive pole (70) of the battery and on the other hand to a terminal (A) which controls the switching means which inhibit the acoustic signal device. Via a resistor (2), the emitter-base line (EB) is also connected (2) to the positive pole (70) and via a second resistor (3) by means of a diode (5) to the series resistor (4) and by means of a diode (8) to the series resistor (7). The optical switching means (B 1, B 2) and the monitoring lamps (K 1, K 2) are connected on the one hand to earth and on the other hand to a positive current rail (78). <IMAGE> |
