The frequency of this circuit depends on the crystal. The transistor supports a modern equivalent. We found it in documentation from the 1980s.
This circuit controls a relay causing it to open and close its contacts at a speed that depends on the...
This digital electronic dice was found in a 1977 magazine, but it can be easily assembled today, as...
This flasher with a small incandescent lamp was obtained in a documentation from the 80's. The...