This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time and the frequency is determined by the crystal. The circuit operates at voltages from 3 to 9 V.
This voltage-controlled oscillator generates signals from 0 to 1.4 kHz with the components...
This circuit is from a 1982 publication. It is a sequential effect of accelerated LEDs. The...
This common operational configuration can be implemented with modern equivalent. Next to the...