basically you need the retarder, a sensor for speed (hall sensor or encoder), a sensor for force/torque (load cell), and a power supply to control the brake.Rube wrote: ↑Jan 10 2018 5:00amHi E-vektor, from your posts I read you have experience with dynometers. I'm interested in a DIY solution for an eddy current braked dyno. Have you observed successful amateur dyno in the power range of common electric motors say 1 to 50kw? In particular, I'm curious about the tools needed to log outputs. Apologies if this is off topic.
The ideal way to control the brake is with a PID controller, so you can get steady conditions and also perform sweep / ramp tests.
In some old dynamometers you could see a potentiometer to provide a direct torque to brake.
Indeed, electric motors are a special case as they can sometimes be tested from high rpm until it stalls by increasing the brake's torque. This normally works with BLDC controllers, since motor torque increases as speed decreases, which leads to a balanced condition as the operator increases brake torque.
But I am not sure if it will work with vector control as torque is more flat in big areas, so speed would be unstable at all those areas (say from 50% speed to 0% speed)
I use the SP5 kit from my company which includes a built-in PID controller, to ease both steady and ramp tests.