This circuit uses a 555 (according to the diagram) to generate 50 ms tone bursts at a frequency of 1.5 kHz. The circuit is from an 80's Electronic Design.
We present a circuit formed by six voltage comparators. Each comparator will analyze the voltage...
This circuit can generate time base signals from 5 to 1500 Hz. We find it in a documentation about old neon...
In this circuit the CA3140, an operational amplifier, is used as a comparator with the zener diode...