Using a 4046 PLL we found this circuit in the December 1989 issue of Radio Electronics magazine. The circuit operates at 220kHz, but this frequency can be changed by changing C3.
This circuit was found in a Electronics Handbook (1989). The shown amplifier provides a few...
This circuit was found in the October 1993 Electronics Now magazine. The output transistors form...
Several types of OSEPP sensor modules can be obtained from Mouser Electronics for Arduino...