Using the CA3140 integrated circuit, this switch was found in the June 1986 Radio Electronics magazine. Sensitivity adjustment is made at the trimpot in series with the sensor.
This circuit indicates the logical level of a CMOS circuit, extracting the power from the circuit...
The circuit of the figure serves the same purpose as the previous one (CB5057E), but has a...
The oscillator in figure 1 can be used in alarm, call or warning systems, producing a sound of...