We found this circuit in the March 1980 Radio Electronics magazine. The circuit used is the HA2400 released at the time. The power supply must be symmetrical.
Two LEDs are used in this TTL circuit. Frequency is given by C1 and C2. Power supply must be a 5 V...
The oscillator shown in the figure generates a rectangular signal with a 50% active cycle (square)...
This circuit was obtained from a Radio Electronics from October 1963. The 4 transistors must be...