This midrange filter for sound systems was found in the May 1988 issue of Radio Electronics magazine. The circuit is based on a dual amplifier that must be powered by a symmetrical source.
We found this circuit in an old documentation for hams. In it we have the way to use a varicap to...
This circuit is from the Philips manual of 1990. The integrated circuit is not very common. The...
This differentiating circuit applies to any operational amplifier. It operates with the negative...