This circuit with TTL compatible output was found in a 1968 US documentation. The circuit is powered by 5 V and the frequency can be changed by changing the crystal.
This circuit is from a 1991 publication, but it can be assembled with more modern components. We...
Found in National Semiconductor documentation from the 90's, this circuit has an output current of...
This circuit was obtained in a June 1987 magazine Hands-On. It is a circuit that indicates on an...