This circuit uses an HA2400 consisting of 4 digitally controlled operational amplifiers. The circuit is from a Radio Electronics magazine from March 1980. The power supply must be symmetrical.
This circuit was found in a 90s European documentation. The circuit already includes a powerful...
This circuit outputs a signal modulated by a unijunction oscillator. The circuit is from a Radio...
This configuration, which uses a transistorized circuit in the feedback, provides a logarithmic response...