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 is the traditional configuration for a limit comparator or window comparator, using two...
We found this circuit in an English publication. The transistor can be BC549, and the power supply...
This simple preamplifier with two transistors may be used in a wide range of applications. The...