RF or even switching transistors like the 2N2222 can be used in this circuit. The capacitors are ceramic and the frequency is determined by the crystal.
We found this configuration, which appears on other of our circuits and with the same or different...
This is the traditional configuration for a limit comparator or window comparator, using two...
With this circuit it is possible to regulate a source of up to 9 A using 3 LM350. The integrated...