This circuit oscillates in the fifth harmonic of the crystal frequency. The circuit is from a 90's documentation. L1 must be according to the desired frequency.
We found this circuit in a manual from National Semiconductor (now Texas Instruments), using the...
In the figure we show how a 2-pole x 2-position switch or HH should be connected to reverse the...
This circuit for the logic control of the 555 in a power supply was found in the October 1989...