This diagram was found in the November 1972 issue of Radio Electronics magazine in an article describing benchtop equipment. The transistors are of the time and the frequencies are given by the coils.
This switching power supply was found in an Electronic Design from the 90s. The components are...
This burglar alarm is highly efficient, depending of course on the care with which it is...
This circuit is from a 1969 Electronics World. The transistors may be modern general-purpose...