Quote:
Originally Posted by johnrobholmes
Pat,
Can you shed a bit of info on how you log the current in the ICE style controllers? A hall effect sensor? Maybe you measure the resistance or voltage drop across some components? Can't say or else I would have to be killed?  I have some haters that are saying the numbers are not even close to a quantification, only an indication of the change in current. |
Shunt - -believe it or not.
For example, on the Mamba XL (which is the same hardware as the ICE-200) we use 4 x .0005 ohm shunts. (for a total resistance of .000125 ohms)
There is an instrumentation amplifier that amplifies the signal.
The absolute accuracy is OK -- +-10% normally. The relative accuracy is very high.
The reason we didn't use Hall sensors is we wanted good response time for ESC protection. Hall sensors are relatively slow, and response times can be too slow to offer ESC protection in short circuit events.
Shunts are very fast -- limited only by the bandwidth of the instrumentation amplifier. But, they are more expensive (because of the high cost of a good instrumentation amplifier...)
Thanx!
Patrick