Wow!! This schematic changes the complexion of this thread. So there's no switch at all, just carbon brushes and a commutator? I say 'Commutator' because this term is usually reserved for DC motors & generators, since Alternators and brush type AC motors use two seperate 360° 'Slip Rings', that don't break contact with the brushes.

 

CDRIVE,
No,there is a switch.AN ELECTRICAL SWITCH IS ANY MECHANICAL (OR EVEN ELECTRONIC)ARRANGEMENT OF MOVING PARTS THAT CAUSE CURRENT TO FLOW OR STOP FLOWING.
The system formed by the carbon brush,B2 and distributor,D,causes current to flow briefly to the coil,and then also switches off the flow of current to the coil after a short while.So i think it is acting as a mechanical switch,or dont you think so?
ezekiel

 

Sure, it's a switch that's opening 18 times per second.

 

That has to be the lamest argument that ever came down the pike.

It's important that when topics are posted that everyone is on the same page. In other words we're all discussing the same device. The proper and accepted nomenclature for this component is a commutator, not a switch, rotary switch or any other kind of switch. If you think differently then you'll have to re-write every text book on the subject since the inception of the electric motor.

This topic should have been titled.

"Reducing Commutator Arcing"

Personally, I find it unfathomable that you thought that was worthwhile posting.

 

Hello,

I have added the "Reducing Commutator Arcing" to the title.

Bertus

 

CDRIVE,am sorry if you think calling a commutator a switch is wrong nomenclature in engineering.I had previously held the view that while the SLIP RING COMMUTATOR is not a switch,the SPLIT RING COMMUTATOR is a switch.I am willing to learn new nomenclatures.AM GRATEFUL TO BERTUS FOR REPHRASING TO "REDUCING COMMUTATOR ARCING",as new title.
Now that you have the circuit diagram,the question remains,WHAT DO WE DO TO STOP,OR AT LEAST REDUCE THE ARCING CONSIDERABLY?
As i stated before,am not an expert in this area and i am prepared to pay for an expert around the NY area who will see the machine and fix the problem for me.It is my research project and this arcing is slowing down my work.I badly need a practical hand who can fix it for a fee.CAN ANY OF OUR RESPECTED SENIOR MEMBERS HELP ME OR RECOMMEND SOMEONE WHO CAN?

 

The common method to reduce arcing in a commutator switch?(found in motors and generators)

is to shift the physical position of the brushes. OR the addition of commutating poles is made to the motor design.

You will not stop the arcing with exterior passive components.

Feel free to disregard this advice and continue pounding your head against the wall.

 

A free wheeling diode across the inductor is a standard fix. The term free-wheeling means that the diode is in a blocking mode under normal operation (reverse biased) and no current will flow. Upon interruption of the 50 Volts DC of the power supply, the inductor now becomes the source and as an inductor, it wants to keep the current flowing in the same direction before the power was interrupted. The diode now becomes the discharge path for the current thru the inductor. Note the diode must be able to pass the full current while the inductor is being discharged.
This phenomenon may be observed on a scope connected across the inductor.

 

Hello,

Did you notice the warning?
You replied to a more than 3 years old thread.
Thread closed.

Bertus