This circuit was found in a 1969 Mullard publication. The transistor may be the modern equivalent of BC548. Observe the relatively high supply voltage.
This circuit is from Dutch documentation from 1967. The circuit works with a component of the...
This interesting capacitive water level sensor was found in Popular Electronics. The circuit can be...
January 2017 - The new Texas Instruments TLV354x series of operational amplifiers with 200 MHz...