Make something turn towards something else at a constant rate?

Hey! I have a flying orb that is constantly trying to laser the player. However I want him to turn at a constant rate and he does not. He turns slower the closer to the player he is.

RotationVar = Quaternion.LookRotation(Target.position - transform.position);
transform.rotation = Quaternion.Slerp(transform.rotation, RotationVar, Time.deltaTime * TurnSpeed);

This is the code making the orb turn (and thus, making the laser go toward the player) but I have no idea what to do with it to make it turn the orb at a constant rate. Any ideas?

public float maxDegreesDelta = 1.0f;
public Transform target = null;

private void Update()
{
    Quaternion current = transform.rotation;
    Quaternion toward = Quaternion.LookRotation(target.position - transform.position, Vector3.up);

    transform.rotation = Quaternion.RotateTowards(current, toward, maxDegreesDelta);
}