I found tis circuit in na old documentation from 1958. The circuit uses germanium transistor availble that time and hard to obtain today. The circuit is indicated for phono applications using variable reluctance transducer.
The contact of the sensor with water or humidity causes the relay to close its contacts. The...
This siren was found in a 1980s documentation. The circuit makes use of very old operational that were...
This circuit was obtained from Motorola documentation from 1969. The setting applies to other...