Found in a 1980s American documentation, this circuit can use a SCR and a general-purpose transistor. R2 is 1 M and R1 is 10k. The capacitor is 47 uF.
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...