Using two 741 operational amplifiers, this low-pass circuit has a cutoff frequency of 10 kHz. We found it in an article in the magazine Electronics Now from August 1993.
We found this circuit very simple in an old documentation. The relay is high voltage sensitive, but...
This circuit was found in an Elektor from the 90s. The circuit uses common components even today,...
The circuit, shown in figure 2, is a monostable multivibrator with two NAND ports out of the 4...