This circuit featuring a new quadruple operational amplifier was found in the March 1980 issue of Radio Electronics magazine. The circuit is to be powered by a symmetrical 15 V source.
We found this circuit on the internet. The components are current, and the time depends on C1...
This circuit was found in an English publication of 1982. The operational can be replaced by an...
With this luminous remote control, which we found in a 1990 publication, using a flashlight you...