This circuit was found in the November 1992 issue of Radio Electronics magazine. The circuit has an amplification stage for the relay. The relay is rated at 12 V.
This circuit uses a 100 kHz crystal, but nearby frequencies can be obtained with appropriate...
Found in an Electronic Design from the 90's, this circuit supplies voltages of 5 V and 3.6 V from...
September 2017 - Texas Instruments PCM186x and PCM186x-Q1 Audio ADCs can be found at Mouser...