def on_current_change(obj=nil, &block)
	
      @on_current_change_obj = obj
      @on_current_change = Proc.new { |device, obj_ptr, motor, current|
	    yield self, @motors[motor], current, object_for(obj_ptr)

	}
      Klass.set_OnCurrentChange_Handler(@handle, @on_current_change, pointer_for(obj))
    end
def on_current_change(obj=nil, &block)
	
      @on_current_change_obj = obj
      @on_current_change = Proc.new { |device, obj_ptr, motor, current|
	    yield self, @motors[motor], current, object_for(obj_ptr)

	}
      Klass.set_OnCurrentChange_Handler(@handle, @on_current_change, pointer_for(obj))
    end
Sets a current change handler callback function. This is called when the current consumed by a motor changes.

 @param [String] obj Object to pass to the callback function. This is optional.
 @param [Proc] Block When the callback is executed, the device and object are yielded to this block.
 @example
     mc.on_current_change do |device, motor, current|
       puts "Motor #{motor.index}'s current changed to #{current}"
     end
 As this runs in it's own thread, be sure that all errors are properly handled or the thread will halt and not fire any more.
 @return [Boolean] returns true or raises an error