Thanks for everyone’s kind responses. I have been considering what you wrote meanwhile this winter storm continues outside. Here is a picture from before the snow fell of my chainsaw skid built from the tress I cut into 3-3/4" slabs.
Those are 10" pneumatic tires; they roll across the lawn and driveway well. The hooks are plywood. I push it from the left side.
I realize I don’t know who I’m communicating with, and they don’t know me.
I would like to take this opportunity to introduce myself with this message I wrote in 2019 around this time of year : My Greeting
TLDR: I did used to be computer progammer, but i found it boring on the computer and most of my colleague in IT are gaining weight and losing hair. So, I decided to change my carrier.
From the discussion, I understood that my own idea of electric-motor was oversimplified. I was thinking, in theroy, of the simplest dynamo: the permanent magnet synchronous motor (AKA AC synchronus) inside of my chainsaw. Synchronous motor - Wikipedia
However, today’s tools are made from motors of many designations:
Permanent Magnet Motors vs Induction motors
Asynchronous vs Synchronous
Brushed vs Brushless
AC/DC And, hybrid types exist today such as the Universal Motor.
That said, all types of electric motors produced share these components; they are the basic elements of a dynamo:
Stator - Stationary part of the motor; the housing
Rotor - The moving part of the motor
Armature - The windings of insulated copper wire around an iron core
Where they differ in designation is with presence of:
Commutator - rotary electrical switch that uses carbon brushes
And, location of the armature. Sometimes it’s in the rotor, sometimes it’s stationary (in stator).
Before we look at some contemporary electric motor designs lets consider this theroy:
At any moment of time, the force applied by an electric motor is the result of a magnetic force created by a current of electricity in a magnetic field. At that moment of time, the electric current can have only one direction. Thus, it could be said that the action of all electric motors are driven by direct current.
However, in order to keep the motor rotating through time the current must reverse. Thus, it should also be said that all electric motors producing rotation and torque rely on changing polarity of an electromagnet via Alternating Current (AC) to rotate.
In Summary, the force is produced by direct current in magnetic field. The rotation is produced by changing polarity of an electro-magnet via an alternating current. It is true for all motors that Force exists with out respect to time, but speed as rotation is driven by alternation of current at a given frequency. In that sense, I am going to say that all motors are AC motors, because they rotate as described.
So, what then is a DC motor? Or a Universal Motor?
It’s a regular electric motor with the addition of a commutator that can switch and control (alternate) current to the motor with built-in circutry.
The commutator can be solid state which operates with brushes, or it can be “electronically commutated” which makes use of semiconductors to operate the motor with efficiency gains.
How can we tell the difference between these types of motors?
Look for brushes. They wear and will need to be replaced.
They should be accessable by removable caps. If you see these caps its a brushed motor.
Look for the capacitor, that’s an AC induction motor. The green arrow points to the weird lump on the stator which contains tube capacitor.
If you are unsure at any time of what type, exactly, your motor is, you can always rip the commutator, capacitor, or any other circuitry out of the motor to convert it to basic dynamo that will run at the speed provided by the frequency of the alternation of current directly to the coils of the motor.
And that is where I would like to resume the discussion, modifying a 12V car-battery inverter to switch it’s AC at a rate faster than 60hz. And thus drive the chainsaw faster. It would also be nice to include a soft start feature that increases the frequency in steps.
This 120V corded Bauer saw is nearly identical to mine.
My goal in this thread is to run it in the field from a 12V car battery + inverter at higher speed by modifying the inverter’s AC frequency. Thanks, and Happy New Year!