We found this circuit in an 80's manual. The same configuration can be adapted to make use of modern operational amplifiers. The power supply is symmetrical.
This circuit was found in a 1964 Electronic Design. The components are of the time, and modern...
This circuit was found in a 1999 publication. Its purpose is to flash two LEDs according to the...
This circuit is from a Popular Electronics from the 90's. The circuit directly drives high power...