The starter circuit shown in the figure was found in an old European documentation. The circuit makes use of an SCR which is still common and the diac can be of any type.
An interesting point of this project is that it is used not only for a robotics project but also...
This remote control by sound or Vox was obtained in a 2004 publication. The circuit is biestable...
This very low frequency circuit was found in a 1964 Electronic Design. Transistors may be modern...