I have a Lorenz-actuator (coil+magnet) that I need to control precisely using a computer. The computer signal is output from a dSpace microLab box as an analog ±10V signal. This signal needs to be scaled to a current of ±5A at roughly 24V. Given the phase shifting properties of coils as well as the underlying physics of Lorenz-actuators, the output current needs to follow the input signal. The system being controlled is highly dynamic and therefore requires a very accurate step response from the current controller. (Perfect tracking up to 200Hz) Four of these actuators need to be controlled so price and size are a factor to consider.
Using a shaker current amplifier: Shakers cant handle any DC, therefore the amplifier has irremovable high-pass filters. My application requires some DC-component in the signal. The ones available to me are also very large and expensive.
Using a voltage amplifier and hoping for the best: Not getting the desired force trajectory from the actuator because current is not being controlled directly. Also can't tune the PID parameters of the control loop.
Using a current controller: I haven't been able to find any online that can drive a current of 5A dynamically. A constant current source is not useful for this application.
Using elmo servo drivers: The output current follows the input signal perfectly, however the drives are completely overkill. They are meant to take a digital signal and control the velocity, position and current of an actuator. Using them as an analog current amplifier is a waste of money.
Does anyone know of an off-the-shelf solution to control the current to the actuator? Or possibly a paper describing how to build a circuit that could amplify an analog current signal?