This is a circuit suggested by Linear Technology in a 1980s documentation. The integrated circuit is from the era. Observe the input and output voltage.
This circuit uses two Raytheon RC4558 operational amplifiers that are similar to the 741. The...
This audio amplifier circuit is from Ibrape's technical documentation from the 70's. The BC177 can be...
This progressive circuit has a lock allowing coded activation. We found this configuration in...