Based on a unijunction transistor, this circuit was found in the January 1994 issue of Electronics Now magazine. The frequency range depends on C1, which can be changed.
With the configuration shown in the figure, a single pulse for a counter can be obtained from a...
With calibrated RV1 it is possible to find a zener diode voltage. The integrated circuit is 0 741...
This circuit was found on an 80's Ham Radio. The transistor admits equivalent. The circuit can...