This circuit was found in a Japanese publication from the 1960s. It uses germanium transistors and is powered by a voltage of 22.5 V. The circuit includes the erasure oscillator.
This sonic, sound or vox switch uses common SCR and transistors can be BC548 or equivalent. The...
This circuit allows you to use a calculator as a timer by directly activating a sum key with...
This circuit is from the time when photos were revealed in darkrooms. We found it in a 1968...