We found this circuit in the 1992 special edition of the Electronics Experimenter Handbook. The components used are still current, many admitting equivalents.
The quiescent current of this alarm is in the order of microamps and the same is true for the...
This circuit is from a 2005 Linear Technology publication. It converts current into load sensing...
This circuit can operate in a 100 dB range with signals of up to 100 MHz frequencies. Similar...