Thursday, February 20, 2020

Negative Feedback

We just learned about the Encoder.

Another part of a servo is Negative Feedback.

When a servo machine is working, and it needs to tell the motor to STOP, it needs some sort of a sensor that tells it when to stop.

A negative feedback part of a machine is something that senses when something gets to a point where it needs to stop, and the movement of the machine stops the machine itself.

That might sound sort of confusing, but if you think about a real world example it makes sense.

In a toilet there is usually a type of ball that is floating in the water in the tank.
When there is no water, the ball is hanging down, which lets the water flow in to fill up the tank.
As the water starts to rise, it gets to the ball and starts to make it float.
When it gets high enough, the ball is floating and it is connected to a valve that closes to stop water coming in.

So the ball floating is the negative feedback saying CLOSE THE VALVE AND STOP LETTING WATER IN, and the more the ball floats up the more the valve closes until it is totally closed and the water stops coming in.

(from: wikipedia - negative feedback)

Kid Facts - Blast from the past: SM-65 Atlas