This circuit was obtained from a Linear Technology manual from the 90's. The integrated circuits are from the time and could possibly be tested as modern equivalents.
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...