The transistors of this circuit found in an English 1980s documentation may be the modern BC548 equivalents. The circuit is battery powered and the earphone must be crystal.
This circuit causes an LED to flash at a frequency determined by the capacitor. The circuit has an...
This low power two-phase motor control was obtained in a 1989 publication. The circuit is for...
This circuit was found in European documentation from the 1980s. The unijunction may be 2N2646 and the...