The circuit in the figure uses two operational amplifiers: an LM101A and an LM102. Diodes admit equivalents and resistors do not have to be accurate. The power supply must be symmetrical.
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...