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.
Found in an article in the August 1971 Radio Electronics magazine, this circuit supports 106...
This sensitive circuit was found in a Texas Instruments optoelectronics manual. The transistors can be...
This circuit was found in a Japanese publication from the 1960s. It uses germanium transistors and is powered...