This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit equivalents although the indicated types can still be found with some ease.
When the power is turned on, the output of this circuit goes to the “1“ logic level by a time...
This circuit was found in an old manual of linear integrated circuits of the 80's. Equivalent...
This is the normal circuit of a relaxation oscillator using an unijunction transistor such as the...