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.
Equivalent transistors can be used in this high impedance and low capacitance circuit. The circuit is...
This circuit uses a modulated signal from a PLL 567 to operate safely with an infrared emitter. The...
In the figure we have a battery charging circuit for currents up to about 5 A. In series with the...