Practice code oscillator (CB21696E)

In the figure we have an astable multivibrator driving a speaker to produce audio signals for Morse code practice.

CSP Power MOSFETs - Panasonic
Panasonic is delivering through its Mouser Electronics its CSP series of power MOSFETs in a range...
Two-Tone Siren LM3909 (CB21236E)
This circuit was obtained from an American documentation from the 90's. The components can be...
Electronic Dice (CB24370E)
This simple TTL electronic dice uses common anode displays. The circuit is from a March 1975 Radio...