This circuit was obtained in a Popular Electronics of the 90s. The circuit uses integrated from the time, uncommon today. Note that the speaker has a higher impedance than ordinary speakers.
The circuit presented is from the National Semiconductor's Linear Applications Handbook of 1994. We...
This is one of the many versions we have of a 12 V power supply with the 7812. We found it in the...
This fader or fader was found in a 90s Popular Electronics. The circuit uses transistors that are...