This low frequency oscillator circuit was found in an Electronic Design from the 90s. The transistors are common types, and the frequency is given by the crystal.
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...