current amplifier??

[pomme]

Hi all,

I am wondering if there is such a circuit called current amplifier? From a quick search on the internet I have found current feedback amplifier ICs, but for my application I need a circuit that will amplify the current

Thanks.

 

[Dx3]

There are ways to do current amplification with opamps. The thing you want the current to go through is placed in the feedback path. Does this idea get you where you want to go?

 

[crutschow]

For normal current measurements you put a small resistance (current shunt) in the circuit and amplify the voltage drop across the resistor, which can be done with an op amp, to give a voltage indication of the current. Another, more complex way which does not use a shunt, is to use a hall effect device and amplifier circuitry to detect the current.

Edit: For currents in the mA or below region you can direct the current into an op amp summing junction (minus input) with a feedback resistor from the output to the junction, to give a voltage output proportional to the current into the junction. The voltage polarity will be negative for a current flow into the input.

 

[MikeMl]

One opamp used as a current to voltage converter, and a second used as a voltage to current converter (with a higher gain). What magnitude of currents? What compliance?