This circuit was published in a 90s Radio Electronics. The circuit uses the well-known LM386 that appears in a large number of projects on this site.
We found this alarm circuit in a Radio Electronics magazine from July 1990. The power transistor must be...
This filter was found in Texas Instruments documentation from the 1980s. The circuit uses a common...
This voltage-controlled oscillator was found on an Elektor from the 90s. The components are from...