We found this circuit in the Linear Applications Handbook by National Semiconductor. The circuit is from 1994, but it can be made with more modern equivalent components.
This bank of switches can be programmed in a variety of ways for logic experiments. The circuit is from...
This filter with the 741 has a Q factor of 8 at the frequency of 1 kHz. The circuit is from a...
The circuit in the figure is suggested by Murata for an uPD75380 microprocessor and is based on a...