This 4093 IC continuity tester was found in the November 1986 Radio Electronics magazine. The circuit powers a ceramic buzzer with a frequency setting.
This circuit was obtained in Motorola documentation from 1969. The transistors are from the time...
The receiver circuit LM567 recognizes the tone set on 555. The connection between the circuits can be made...
This is a bridge for the measurement of low value resistances and high values too. The circuit...