The frequency of this circuit is approximately 1 Hz. Whenever the output is at low level, the LED will light up. The active cycle of the generated signal is approximately 50%. LM339 can be used with voltages from 5 to 12 V.
![](/images/stories/cir/223412342023_170234_0001.png)
The frequency of this circuit is approximately 1 Hz. Whenever the output is at low level, the LED will light up. The active cycle of the generated signal is approximately 50%. LM339 can be used with voltages from 5 to 12 V.