This circuit was found in a PE Hobbyst Handbook of 1989. It uses a black light fluorescent of the time. Small fluorescent black light from 1 to 4 W can be used.
This circuit was found in a 1986 publication. However, it can still be easily assembled, as the...
This circuit was published in Radio Electronics magazine in June 1959. The circuit uses an...
This circuit is based on an old Siemens integrated that can now be found very easily. It allows the...