This low frequency divider uses unijunction transistors. The bipolar transistor can be a BC548 and the zener diode Z4XL can be a 12 V zener. The circuit was found in a 1967 publication.
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...