Hi all,
I am planning to programmatically control the speed of a motor loading a seafloor anchor (just a model anchor in the lab for now). The idea is to mimic cyclic wind and wave loads the anchor will see at sea.
To do this, I would like to replace:
the 5 k-Ohm, 0.5 W analog speedpot that came with my Dart 130HC100 motor controller
with a digital potentiometer:
something like the MCP4161 or AD5160.
I can successfully communicate with these devices through Arduino and see the resistance change according to the codes I send. But when I turn on my motor controller with a digital potentiometer connected, the resistance immediately goes very high (measured this with multimeter)! Correct me if I'm wrong, but I believe the current flowing through the controller is overloading the digital potentiometer which fails open-circuit.
My question is, does anyone know some programmable/digital potentiometers that have higher power ratings? I noticed on the AD5160 data sheet that the maximum current across the wiper terminals is only about 5 mA.
And using Power = I^2 * R, I think the 5 k-Ohm, 0.5 W analog speedpot can handle about 10 mA, so about 2x what I am trying to replace it with.
Thanks much for any insights!
Jeff
PS. I attached the data sheets for each of the digital potentiometers mentioned, and also the 130HC100 controller.
I am planning to programmatically control the speed of a motor loading a seafloor anchor (just a model anchor in the lab for now). The idea is to mimic cyclic wind and wave loads the anchor will see at sea.
To do this, I would like to replace:
the 5 k-Ohm, 0.5 W analog speedpot that came with my Dart 130HC100 motor controller
with a digital potentiometer:
something like the MCP4161 or AD5160.
I can successfully communicate with these devices through Arduino and see the resistance change according to the codes I send. But when I turn on my motor controller with a digital potentiometer connected, the resistance immediately goes very high (measured this with multimeter)! Correct me if I'm wrong, but I believe the current flowing through the controller is overloading the digital potentiometer which fails open-circuit.
My question is, does anyone know some programmable/digital potentiometers that have higher power ratings? I noticed on the AD5160 data sheet that the maximum current across the wiper terminals is only about 5 mA.
And using Power = I^2 * R, I think the 5 k-Ohm, 0.5 W analog speedpot can handle about 10 mA, so about 2x what I am trying to replace it with.
Thanks much for any insights!
Jeff
PS. I attached the data sheets for each of the digital potentiometers mentioned, and also the 130HC100 controller.
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