Update mixer.md

doc/mixer.md

@@ -279,9 +279,9 @@ We can also make it more interesting by adding the ability to switch between wav
 via a switch. This is left as an exercise.
 
 ### Example 19: Random servo motion generator
-Suppose we have a model equipped with a turret, or a figure. What we would like is to move it automatically but in a 
-random and intermittent manner, as we can't always be controlling it manually, for we only got one brain :)
-<br>We can easily achieve this behaviour with function genarators and logical switches as follows.
+Suppose we have a model equipped with a turret, or a figure. We want the servo to move automatically but in a 
+random and intermittent manner.
+<br>We can achieve this behaviour with function genarators and logical switches as follows.
 
 ```txt
 Function generator Fgen1
@@ -299,7 +299,7 @@ Func:   a>x
 Value1: Fgen2
 value2: 0
 ``` 
-Then in the mixer, assuming our turret servo is on Ch7,
+Then in the mixer, assuming our servo is on Ch7,
 ```txt
 1. Ch7   Add  Fgen1 (Weight 100)          
 2. Ch7   Hold       (L1)