This filter is from the Linear Applications Handbook of the National Semiconductor of 1994. However, it can be used with other operational and modified to operate with other frequencies.
This circuit is from a Radio Electronics from October 1963. The LDR and transistors are from the...
The figure shows how to use an operational circuit as a voltage divider. The circuit is from a...
This is the basic configuration of an operational amplifier as a current regulator. We found it in...