We found this circuit in a 1964 Electronic Design. Transistors can be modern general-purpose equivalents. The circuit converts a 1 MHz sinusoidal signal into a rectangular signal.
Found in old documentation, this circuit uses components that are still common on the market. The...
This circuit activates a relay by activating one of a series of optical sensors that can be...
We found this circuit in a 1996 publication. Equivalent components can be tried, especially in the...