The frequency of this circuit depends on C1 and, for the indicated values, it is 1 kHz. Equivalent operational amplifiers can be used, and the power supply must be symmetrical.
This circuit using only transistors was found in documentation from 1977. The frequency is 4250...
This circuit was found in a 1992 publication. What it does is to light an external lamp when it...
This simple two-transistor circuit used transistors from the 60s, having been found in a...