This 4093 IC continuity tester was found in the November 1986 Radio Electronics magazine. The circuit powers a ceramic buzzer with a frequency setting.
August 2017 - STMicroelectronics' new T850 switches with triacs up to 8 A can be obtained from...
This circuit is from the 1990 Motorola Linear Databook. The circuit can be applied to other...
Found in documentation from the 90s, this circuit makes use of components from the time....