| 摘要 |
The aim of the invention is achieved by means of a facility which can be characterised in that a two-stage IC amplifier (3) which is connected to sensor points (2), and a potentiometer, which is situated between the individual stages, and has a symmetrical input, is connected on the one hand to an LED indicator (4), which advantageously contains an LED series (6) of 16 elements and a UAA 170 type IC, which is in functional relationship thereto, and on the other hand to an acoustic warning device (5) which contains a gate circuit, built together with a tone-imparting device (7), of capacitors and resistors and a Z-diode, which is connected to the latter. The feeding unit (8) of the facility contains eight baby cells, each of 1.5 V. Their maximum current take-up amounts to approximately 20 mA, so that a set of cells permits at least 50 operating hours. The so-called baby batteries can also be used for reasons of economy. Operating from the mains is not advisable, since filtering of the interferences occurring there and protecting against contact would require complicated and expensive circuit solutions. After switching on the main circuit, the cell voltage can be monitored on an indicator instrument incorporated directly for this purpose. <IMAGE> |
