Solid vs Stranded

You can if the DC bias is close to 1/2 the peak to peak AC.
The dividing line between AC with a DC bias and DC with close to 100% ripple seems to be different depending on what field you are in. :happyyes:
I am also perfectly happy to call it pulsed DC with ringing as long as the order of magnitude of the pulse frequency and the ringing frequency is part of the discussion.
I used to call it AC until I was corrected by engineer types that explained to me that AC meant a voltage that alternated from positive to negative polarity and that was not what was happening in ignition systems and lightning.

I have to bow out when it comes to terms like ringing frequency. I am not familiar with that term, thus I don't see the relationship between it and AC/DC differentiations.

Here it is in man on the street terms. AC is voltage that alternates from one polarity to another and that usually happens at a discernible frequency. DC always stays the same polarity, but can be turned on and off, creating and collapsing a magnetic field and taking on the characteristics of AC, while still remaining to be direct current by definition, but turning on and off at a discernible frequency. As opposed to changing polarity at a frequency
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I have to bow out when it comes to terms like ringing frequency. I am not familiar with that term, thus I don't see the relationship between it and AC/DC differentiations.
If you apply an impulse or step change to a tuned LRC circuit there will be an oscillation at the resonant or ringing frequency. Like the frequency from a bell when you hit it.
In an old fashioned ignition circuit (still taught in non-automotive schools) the resonant frequency of the coil L and the condensor C, damped by the loss of current to the spark, will produce a high frequency sine wave component that you can see with a high frequency capable scope. And the magnitude of the DC will also decrease as the plug bleeds voltage off.
The very first half cycle may come close to the 0V DC line, but it is quickly damped.
If the condensor is bad there is arcing at the points which damps the waveform even faster and produces a lousy spark (technical term.)
 
Location
NC/SC
So here I am reading your discussion, with no apparent application to my day to day experiences,(and little comprehension) when suddenly it all becomes relevant.
Thanks guys, that's why my 1949 Ford 8N is running so bad. I discovered I left the ignition switch on, the rotor was in contact position, the battery was dead the coil was bad. I changed the distributer cap, rotor, coil, and plugs but not the points and condenser. I must have damaged the condenser as well. Now I understand the condenser and points need to be changed because they where damaged and are damping the spark. I also learned why not to leave the ignition switch on. There must be current flowing somewhere in the ignition circuit when the ignition is on even when the engine is not running. Thanks. I love this forum.
 

iwire

Moderator
Staff member
Location
Massachusetts
So here I am reading your discussion, with no apparent application to my day to day experiences,(and little comprehension) when suddenly it all becomes relevant.
Thanks guys, that's why my 1949 Ford 8N is running so bad. I discovered I left the ignition switch on, the rotor was in contact position, the battery was dead the coil was bad. I changed the distributer cap, rotor, coil, and plugs but not the points and condenser. I must have damaged the condenser as well. Now I understand the condenser and points need to be changed because they where damaged and are damping the spark. I also learned why not to leave the ignition switch on. There must be current flowing somewhere in the ignition circuit when the ignition is on even when the engine is not running. Thanks. I love this forum.
:thumbsup:

Awesome.
 

mbrooke

Batteries Not Included
Location
United States
Occupation
*
So here I am reading your discussion, with no apparent application to my day to day experiences,(and little comprehension) when suddenly it all becomes relevant.
Thanks guys, that's why my 1949 Ford 8N is running so bad. I discovered I left the ignition switch on, the rotor was in contact position, the battery was dead the coil was bad. I changed the distributer cap, rotor, coil, and plugs but not the points and condenser. I must have damaged the condenser as well. Now I understand the condenser and points need to be changed because they where damaged and are damping the spark. I also learned why not to leave the ignition switch on. There must be current flowing somewhere in the ignition circuit when the ignition is on even when the engine is not running. Thanks. I love this forum.
I know right? :lol: I get epiphanies from the most random threads on topics that have little to nothing with the OP. At first that would sound counter productive but it actually adds to the value of each thread including the OP's original question. Its a paradox but one I like :D


Glad you found the problem with your truck, and btw keep that thing running no matter what. New stuff is well... :sick::sick:
 
So here I am reading your discussion, with no apparent application to my day to day experiences,(and little comprehension) when suddenly it all becomes relevant.
Thanks guys, that's why my 1949 Ford 8N is running so bad. I discovered I left the ignition switch on, the rotor was in contact position, the battery was dead the coil was bad. I changed the distributer cap, rotor, coil, and plugs but not the points and condenser. I must have damaged the condenser as well. Now I understand the condenser and points need to be changed because they where damaged and are damping the spark. I also learned why not to leave the ignition switch on. There must be current flowing somewhere in the ignition circuit when the ignition is on even when the engine is not running. Thanks. I love this forum.
If the ignition is left on, and the points are closed, current will flow through the coil and possibly damage ignition parts. It will also run the battery dead.

If the points are in the open position, no current flows and no harm will come. Of course we don't know what state the points are in when we forget to turn the ignition off.....

Points and condensers should always be replaced together. You may be able to get a 'uni-point' set that has both in one assembly.
 

mgookin

Senior Member
Location
Fort Myers, FL
So here I am reading your discussion, with no apparent application to my day to day experiences,(and little comprehension) when suddenly it all becomes relevant.
Thanks guys, that's why my 1949 Ford 8N is running so bad. I discovered I left the ignition switch on, the rotor was in contact position, the battery was dead the coil was bad. I changed the distributer cap, rotor, coil, and plugs but not the points and condenser. I must have damaged the condenser as well. Now I understand the condenser and points need to be changed because they where damaged and are damping the spark. I also learned why not to leave the ignition switch on. There must be current flowing somewhere in the ignition circuit when the ignition is on even when the engine is not running. Thanks. I love this forum.
The consult fee is one posted photo of that awesome tractor please...:D
 
You know beyond the big weight difference the fix was in on that steam tractor vs new tractor tug.

The chain is connected higher up on the steam tractor and that gives it a huge advantage. It plants the steam tractors wheels while lifting the new tractors wheels.
I think the weight difference was the entire advantage.

If the steam engine had the rear wheels locked, in 'park' so to speak, the JD wouldn't have been able to move the steam engine one bit, no matter where the chain was connected.

If it were the other way around, with the JD in 'park', the steam engine not only could pull it, but it would hardly notice the load.

The chain attachment point did not lift the new tractor. Look at the video. The new JD dug itself into a hole nearly a foot deep.
 

iwire

Moderator
Staff member
Location
Massachusetts
I think the weight difference was the entire advantage.

If the steam engine had the rear wheels locked, in 'park' so to speak, the JD wouldn't have been able to move the steam engine one bit, no matter where the chain was connected.

If it were the other way around, with the JD in 'park', the steam engine not only could pull it, but it would hardly notice the load.

The chain attachment point did not lift the new tractor. Look at the video. The new JD dug itself into a hole nearly a foot deep.
And the JD would not have likely dug a hole if the chain was higher on the JD then the steam. When I say 'lift' I mean remove weight from the wheels. Its a fact not a guess.

You know this, any force on the chain has equal and opposite reactions, unless the chain is straight from hitch to hitch it will lift one tractor and add down force to the other.

If you ever try to pull stumps out you learn this trick pretty quick, use a short chain, low on the stump higher on the tractor. It plants the wheels, just watch out becuse this is also how you can flip a tractor. :)

All this aside, you know those tractor guys know this about hitch height importance so if they where really interested in a true competition the chain would have been straight. I am sticking with someone was looking for an upset.
 

mgookin

Senior Member
Location
Fort Myers, FL
And the JD would not have likely dug a hole if the chain was higher on the JD then the steam. When I say 'lift' I mean remove weight from the wheels. Its a fact not a guess.

You know this, any force on the chain has equal and opposite reactions, unless the chain is straight from hitch to hitch it will lift one tractor and add down force to the other.

If you ever try to pull stumps out you learn this trick pretty quick, use a short chain, low on the stump higher on the tractor. It plants the wheels, just watch out becuse this is also how you can flip a tractor. :)

All this aside, you know those tractor guys know this about hitch height importance so if they where really interested in a true competition the chain would have been straight. I am sticking with someone was looking for an upset.
I disagree (very respectfully of course).

Higher hitch point on the green machine would have toppled the green machine backwards.

That other tractor was a locomotive adapted for farming!
 

mbrooke

Batteries Not Included
Location
United States
Occupation
*
Ok, back on topic :p

After much research (albeit much of it was over my head), Ive read that stranded conductor has lower AC losses than solid conductor. Is this all due to skin effect or some other force? Is it that stranded is basically a multi conductor cable and air voids in the cable act as an insulator against each strand?
 

mgookin

Senior Member
Location
Fort Myers, FL
Ok, back on topic :p

After much research (albeit much of it was over my head), Ive read that stranded conductor has lower AC losses than solid conductor. Is this all due to skin effect or some other force? Is it that stranded is basically a multi conductor cable and air voids in the cable act as an insulator against each strand?
One factor in the magnitude of the electric field around a conductor is the radius of the conductor.
It's actually r^2 so a smaller diameter conductor means less loss = greater efficiency.
 

mbrooke

Batteries Not Included
Location
United States
Occupation
*
One factor in the magnitude of the electric field around a conductor is the radius of the conductor.
It's actually r^2 so a smaller diameter conductor means less loss = greater efficiency.


Electric field as in capacitive field? Is this why high voltage transmission lines often have parallel or triple conductors per phase?
 

tyab

Member
Here is the listed class 1 down conductor I am using for a 780 compliant lighting protection system for a solar ground mount. 32 strands of 17 gauge wire in basket weave. 65,500 circular mil cross section. That basket weave appears to be at all layers - impressive stuff.
 
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