This circuit was found in the April 1978 Radio Electronics magazine. The power supply must be symmetrical, and the maximum operating frequency is around 100MHz.
In this circuit the LED lights up when the input voltage exceeds the value set in the trimpot. The circuit...
Other series comparators such as the LM239 and LM339 can be used in this oscillator circuit. The...
This is one of many possible metronome configurations using the 555. We found it in an Electronics...