Found in a Popular Electronics from the 90s, this circuit generates signals from 2 Hz to 30 kHz in different bands. The circuit can be powered by voltages from 5 to 12 V, depending on the application.
This active crossover filter was obtained from the component manual used. Below is the performance...
This circuit is from an 80's documentation. It makes use of two SCRs with current capacity...
This interesting idea was found in a 1983 publication and is very simple to analyze, according to the...