Amplifying feeble AC voltage from small coil which is having the presence of magnet

[varunme]

Amplifying feeble AC voltage from small coil which is having the presence of bar magnet, which i want to use as a sensor of movement

someone help me in making in amplifier, can i build with opamp ?

 

[jeffrey samuel]

You can use any amplifier design But with out knowing the exact input Voltage and the op power you need no one in this earth can help you to find a solution

Do post the signal strength of the feeble signal you get and also the strength of the op signal you need

 

[varunme]

when moving the magnet very fast ( actually its an encoder in a magnet) , multimeter shows 1V , i like to get 5V so that can be fed to uC

 

[jeffrey samuel]

Use an LM741 in inverting amplifer configuration That should do the job for you

Use Rf = 5k and the Ri around 1k for getting the desired output

 

[varunme]

can i use lm358 also ?

 

[jeffrey samuel]

These devices consist of two independent, high-gain, frequency-compensated operational amplifiers designed to operate from a single supply over a wide range of voltages. Operation from split supplies also is possible if the difference between the two supplies is 3 V to 32 V (3 V to 26 V for the LM2904), and VCC is at least 1.5 V more positive than the input common-mode voltage. The low supply-current drain is independent of the magnitude of the supply voltage.

Applications include transducer amplifiers, dc amplification blocks, and all the conventional operational amplifier circuits that now can be implemented more easily in single-supply-voltage systems. For example, these devices can be operated directly from the standard 5-V supply used in digital systems and easily provide the required interface electronics without additional ±5-V supplies.

This is true so you can use it

Here you will use a single supply but the same design procedure as that of the Lm741