This circuit identifies the polarity of DC signals and if the signal is AC. The circuit is from 1969 US EDN documentation. Operational may be equivalent.
This circuit is from the 80's, using an integrated of the time. The circuit serves as a reference,...
This circuit was obtained from an American 80's documentation. The operational ones can be...
This logarithmic gain operating configuration was found in the June 1994 Electronics Now magazine. The...