Using JFETs, this circuit from a 90’s American documentation can generate signals of 0.15 Hz. The JFET can be of any general-purpose type like the BF245 or MPF102.
This simple robot or motor control circuit using a photocell as a sensor was found in the magazine...
This circuit uses an operational amplifier to modulate the light emitted by an LED with audio...
Equivalent transistors, such as the BC548, can be used in this circuit that we find in...