This common circuit using operational amplifiers was found in the 1993 issue of Radio Electronics Special Projects. The circuit is sandwiched between the pickup and the amplifier input.
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...