This simple circuit has good gain and can be implemented with any general-purpose transistor. The circuit is from Electronics Now, June 1997. The coil determines the frequency range.
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
This circuit causes the relay to be energized when the input voltage exceeds the voltage value of...
This circuit can be used in 0,5 to 37 V Power supplies and output currents up to 3 A. The...