Found in a 1967 Delco documentation, this circuit can deliver power from 40 to 50 W at 8-ohm load. The response ranges from 20 to 20 000 Hz. No information is given about the transformer used.
Found in a 90s Popular Electronics, this touch switch uses a single sensor. PLLs are common today....
We found this circuit in an old documentation from 1979. It is a logic level tester that is...
This ultrasonic insect repellent was found in American documentation from the 1980s. The...