We found this circuit in a Poptronics from 1998. The circuit can be extended to more competitors with another 4011. The power can be made with voltages from 6 to 12 V.
Capacitors determine the frequency range together with resistors, and these components can be...
This circuit was found in the June 1970 Radio Electronics magazine. The power to the load is triac...
This circuit has its application suggested in an alarm system. The circuit is from an old RCA...