| 摘要 |
<p>The signal transfer circuit consists of a primary 1. v. circuit and a galvanically separated, secondary mains voltage circuit. An external signal generator momentarily effects the mains voltage so that a signal appears at each position coupled to the mains. A receiver detects these signals for the release of secondary signals. By means of a semiconductor relay, the secondary circuit can be momentarily interrupted over a complete count of 50Hz half-waves. This momentary interruption can be used to release optical or acoustic signals. The length of this interruption can be selected from one to two mains frequency half-waves. This circuit enables an optical or acoustic signal to be conveyed to selected positions, e.g. rooms of a flat, from a remote position, e.g. a front door.</p> |
