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.
Applying a high voltage to a mixed lamp can obtain a bluish light with a decorative effect. This...
This circuit was obtained in a 1976 magazine. We can use the 555 and another BC548 to generate square...
This AC operational amplifier has a power stage and a gain determined by R2. The maximum output...