| 摘要 |
<p>An alarm circuit includes a suppression stage to eliminate the effects of any disturbance to the system. The alarm sensor (2) is coupled over twin cable (3, 4) to a bridge circuit connected to a differenterial amplifier (5). A regulating resistor (6) allows the bridge to be balanced the resistor together with a capacitor (8) forms an RC filter that suppresses any disturbances above 30 Hz. The circuit ensures that a complete check of signal features e.g. voltage, current and phase is made before acceptance occurs.</p> |
