We found this circuit in an Electronic Design from 1965. The 4-layer diode is an unusual component these days and can be used in its place with a diac.
This source of constant current was obtained in an American documentation of 1973. The transistors can be...
Unlike white noise, pink noise has a spectrum whose amplitude decreases with frequency. This...
This circuit was found in a 1985 English magazine, but it can still be easily assembled, as the...