The transistor used in this circuit is uncommon today. AC124 or equivalent such as AC188K and 2N2431 can be used. The circuit is from the 80's and makes use of transformers.
This circuit is based on the voltage reference that is uncommon today MC1403. Equivalents can be...
The phasor is the ray weapon that we see in many science-fiction films. The characteristic sound can be...
This sonic control circuit for a small robot turtle was obtained in an American documentation from 1967....