We found this circuit in a 1980s American documentation. The operational amplifiers of the integrated circuit used can be common types in an experimental setup.
This circuit can be used in decoration or to draw attention, in a “fake” assembly for example. What he...
This filter was found in Exar documentation from the 1980s. The circuit has an attenuation of 60 dB at the...
This windshield wiper timer was obtained in an 80's Hands On. The transistor can be the BC548 and...