This 555-based circuit was found in the August 1976 issue of Radio Electronics magazine. The tone frequencies are provided by the capacitors connected to the 555 IC.
This amplifier was found in a 70s documentation. The product gain x bandwidth is 350 MHz. The...
This circuit mimics the trill of a bird. We found it in an American documentation from the 90s. It is...
With the values indicated for this circuit, the lamp will flash 60 times per minute (1 per...