Found in a 1991 PE Hobbyst Handbook, this circuit activates an oscillator that deactivates at the end of the programmed time. Transistors are commonly used.
The cut-off frequency of the filter shown in the figure can be adjusted to values between...
This circuit was found in a Popular Electronics from the 90s. The components used are all common...
This circuit uses a dual floodgate MOSFET not very easy to obtain today. Its handling is very...