What is master ALT?

I’m trying to figure out what MASTER ALT does in the C172 and Xcub. It doesn’t seem to do anything. Can anyone help?

Controls the alternator

What is that?

It is a voltage control unit I think

But what exactly does it do in the aircraft? I want the big picture.

It controls the system voltage.

And what does that do?

It makes sure the voltage in the aircraft stays normal.

It makes sure the required voltage is met to meet certain requirements of the aircraft such as fuel pump etc.

The alternator generates electricity from the engine to maintain battery level as in an automobile. The difference between a generator and an alternator is that an alternator generates varying current (AC) while a generator has the extra step of converting the AC to DC. As in an automobile the purpose is to powers lights, avionics, spark plugs, flap motors, and recharges the battery after ignition.

It’s a pretty straightforward structure that converts mechanical energy to electrical energy by having mechanical energy from the engine push magnets through coiled wires, which due to fundamental laws of physics, induces an electrical current in the wires.

The mechanical energy to do this, comes from the chemical energy released when fuel explodes in the cylinders.

Yes, having your lights on, uses a tiny bit more fuel.

If you were to yourself push a magnet through a coil of wires used to light a light bulb, your muscles would feel a slight resistance. That’s why you need the fuel energy to drive it all.


This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.