This circuit was found in a Popular Electronics from the 90s. The counter circuit is not common today. The circuit can be programmed for hourly intervals, according to the values of R4 and C2.
This circuit turns on a lamp after the time set on the potentiometer. The circuit is from a Radio...
This signal amplifier for ATV in the 427 to 439 MHz band was found in a magazine 73 for radio...
This amplifier has a few Watt output, using old transistors. The speaker is 45 ohms, but with...