This detector was found in an old Electronic Design using transistors of the time. The circuit can be made with modern equivalent transistors. See the charts with your performance.
August 2017 - New DTMOS Super Junction MOSFETS from Toshiba are in stock at Mouser Electronics....
This delay circuit for a sound system was found in the December 1990 Radio Electronics magazine as part...
This 3V-only circuit was found in old American documentation, but can be implemented with...