This circuit can use a pendulum sensor. We found this configuration in a 1994 publication. The components used are common and the timing is given by the capacitor C1 which can be changed.
This CMOS integrated alarm was found in the July 1992 Radio Electronics magazine. The circuit has...
This is the configuration of this type of oscillator given in an article in Electronics Now...
Used by radio amateurs to accompany telegraphic transmissions, this circuit generates an audio...