This circuit that can be activated by light or heat was found in an old American documentation, but the components it uses are perfectly current. The power transistor shall be fitted with a heat sink.
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...