This circuit was found in a Popular Electronics from the 90's. The transistors are general-purpose types and the loaded load depends on the voltage and must have a maximum current of 100 mA.
This sophisticated alarm with traditional components was found in an ancient American...
September 2016 - can already be purchased at Mouser Electronics the Robot Scribbler S3 from...
This circuit produces rectangular and triangular signals using two 741 operational. The source must...