We found this code switch circuit in the January 1999 Electronics Now magazine. Some of the components are integrated circuits from that era.
The CMOS TLC555 can be gated from external CMOS circuits using the configuration shown here. The...
In the figure we have a two-channel preamplifier with two 741 integrated circuits. The circuit is from a...
We found this circuit in a documentation from the 50's. The transistors are germanium types. The...