This circuit allows the activation of a remote telephone bell made with a common piezoelectric capsule. The circuit does not need power, as it is powered by the line call signal itself.
This car alarm was obtained in a Signetics documentation from the 1980s. The circuit uses the 555...
The frequency of this circuit can be varied from zero. The circuit uses the CMOS 4046 and was...
This simple binary counter triggers two LEDs according to the number of pulses applied to the...