This non-inverting comparator was found in old American documentation. Formulas next to the diagram allow you to calculate the components for the desired performance.
The frequency of this circuit depends on the crystal. The transistor supports a modern equivalent. We...
Indicated in Maxim's documentation from the 90's, this circuit has a gain of 40 dB and an output...
The time obtained in this circuit, from a 1978 publication, depends on R3 and C. R3 can have...