concepts of electricity you found interesting ..

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For me I was always around electrical items since my dad & uncle were electricians and was always asking them questions and attended the best Vo Tech school around. Understood had relays, starters & motors worked but still amazed over VFD'S. First ones that I worked on were 1.5 to 3 HP that had believe 8 boards . Each of 6 boards controlled halve of a three phase output , one was the control board and last was power supply. Had limited adjustments via pots such as ramp up & down down & torque. When drives advanced to digital controls and much superior IGBT'S & over a hundred parameters and do.much memory like total hours, total power consumed, last 10 fault codes, heat sink temperature etc. Worked at a newspaper where Allen Bradley made a special drive just for the paper reel tension & being able to make a running paper splice in newsprint moving over 40 MPH. While attending their drive class they told us that it took a team of brilliant people 10 man years to perfect the program.
 
garbo said:
For me I was always around electrical items since my dad & uncle were electricians and was always asking them questions and attended the best Vo Tech school around. Understood had relays, starters & motors worked but still amazed over VFD'S. First ones that I worked on were 1.5 to 3 HP that had believe 8 boards . Each of 6 boards controlled halve of a three phase output , one was the control board and last was power supply. Had limited adjustments via pots such as ramp up & down down & torque. When drives advanced to digital controls and much superior IGBT'S & over a hundred parameters and do.much memory like total hours, total power consumed, last 10 fault codes, heat sink temperature etc. Worked at a newspaper where Allen Bradley made a special drive just for the paper reel tension & being able to make a running paper splice in newsprint moving over 40 MPH. While attending their drive class they told us that it took a team of brilliant people 10 man years to perfect the program.
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I worked at a newspaper mailroom while in high school. The press room was visible through big glass windows. I’ll never forget the chaos that ensued when something went awry while those 40 mph presses were running.
 
Can remember when they had a bad wrap while running presses and it would take 20 to 30 minutes to carefully cut an inch of paper off chrome roller so as not to nick it then reweb paper from basement up to third level then down thru folder section.
 
Its cords and plugs, different methods of protection, so much theory in what seems a simple system, so much of it is invisible. I am constantly amazed by guys I think should know better that make the statement,,, all the breaker does is protect the wire in the wall from overheating.
 
Sberry said:
Its cords and plugs, different methods of protection, so much theory in what seems a simple system, so much of it is invisible. I am constantly amazed by guys I think should know better that make the statement,,, all the breaker does is protect the wire in the wall from overheating.
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Those guys never saw someone use bootleg power in the 3rd world with no over current protection and still not instantly vaporize their 3mm wire its on.
 
My bud worked in 80 countries, said he bout died in one from one of these deals. Another he said they were waling between buildings and seen rebar sitting on concrete blocks, guy says,,, dont touch that, it was 480 feeding the other plant.
 
letgomywago said:
Those guys never saw someone use bootleg power in the 3rd world with no over current protection and still not instantly vaporize their 3mm wire its on.
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I haven't been to the third world country and seen it up close, but have seen plenty of things that some were surprised didn't burn the place down, I say those were just lucky to not actually be overloaded enough or experience the short circuit that could have done so and would guess you could say same thing in most those third world installs as well.
 
For me, the fascinating thing about electricity, is how the concept of impedance extends Ohm's law to wildly different components from simple resistors, and still allow us to use the same mental exercises for keeping track of voltage and current for series and parallel networks. A practical application of complex numbers, you'd never expect when you are first introduced to them in general mathematics.
 
Sberry said:
My bud worked in 80 countries, said he bout died in one from one of these deals. Another he said they were waling between buildings and seen rebar sitting on concrete blocks, guy says,,, dont touch that, it was 480 feeding the other plant.
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Reminds me of speed wiring while in Viet Nam. After zappers blow up 5 helicopters one night somebody sent an officer to pull me & my Sargeant out of the club to pull tons of #2 cable, & mount & wire in maybe 50 500 watt floodlights around our little flight line. The major told this warrant officer that he wanted the lights up & running by morning. Told them if we had the six fastest electricians in the world would still take days. They brought in PA&E ( fly by night Pacific Architects & Engineers ) to help. All of the cables were 100' lengths of welding cable. We could not get any split bolt bugs so stripped long lengths then tie square knots in made up fingers then only had enough tape to give it a few wraps then onto wet ground. PS&E made splices in under 30 seconds. They cut the head off a roofing nail then jambed it into cable ends followed by 2 wraps of tape. Lights worked for a few minutes until nails got hot. Between the on & off & dim to bright distracted soldiers on guard duty that we had to turn them off . Corner cutting fast track too often a complete failure.
 
garbo said:
Reminds me of speed wiring while in Viet Nam. After zappers blow up 5 helicopters one night somebody sent an officer to pull me & my Sargeant out of the club to pull tons of #2 cable, & mount & wire in maybe 50 500 watt floodlights around our little flight line. The major told this warrant officer that he wanted the lights up & running by morning. Told them if we had the six fastest electricians in the world would still take days. They brought in PA&E ( fly by night Pacific Architects & Engineers ) to help. All of the cables were 100' lengths of welding cable. We could not get any split bolt bugs so stripped long lengths then tie square knots in made up fingers then only had enough tape to give it a few wraps then onto wet ground. PS&E made splices in under 30 seconds. They cut the head off a roofing nail then jambed it into cable ends followed by 2 wraps of tape. Lights worked for a few minutes until nails got hot. Between the on & off & dim to bright distracted soldiers on guard duty that we had to turn them off . Corner cutting fast track too often a complete failure.
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great story .... thank you for your service.
 
I think its interesting to note how 90% of the stuff havnt changed in forever, how the equipment people design to enable to utilize it and plug in to a code compliant outlet. The welders are neat, the same fundamental allowance for wire size, same code for this circuit with a lot of opin on how it should have been changed or modified and over all the decades of inovation have managed to use the same fundamental circuit that has been there since it was invented.
I didnt follow everyone in the new generation, I looked at the Hobart Miller which is innovative in its own right but maybe the other guys had the lock on the other concept of a 120 to 240 adapter vs the 240 to 120.
Despite wide use (by others as I am in my own world) I even ask on forums and it was a short conversation about how it all worked.
 
Anyway for anyone that cares and feel free to correct,,, the 120 is just an adapter, great for lost adapters, could make one without altering the rest of the factory cord. In both systems the 240 end is special allowing 50 to 30 and on 120 the system breaker will provide both thermal and fault and the adapter will even pass 30 and with the Hobart the end is changeable, the adapter is 50 to 30 at 240 and simply plugs in to a 20A outlet at 120 relying on the supply for protection. Make sense????
 
Everyone is in awe of new 400A welder and iuts great too but the MVP scheme is one of the best things they ever invented for welding. If you would have asked me at the beginning and even in 10 or 15 years I thought we see that so fast at this price I would have said no way no how.
Half a nuke power plant is built 3/32 7018. I dont know how much the remote cost then, north of a grand and had 4/0 cable, could cook on it. Now, they can use the same 10 120V service wire they got the rest of it on which wouldnt be burdened by 1000 incandecants anymore, all that replaced by a machine with a 14 cord and 30A twist lock parked next to a little rod heater. Grinding a separate scheme, might still be done air but no more switching polarity at the source for tig, welder and remote all in one.
 
It was a while back and was a sprout, I recall the cord to the heater as being 16 and wondered why and later looked it up, I see it is allowed on a 30. They had molded Y cords, not 3 way but Y with twist lock and believe it was 30. At the time it was lights and rod ovens and some specialty equipment like a mag drill. I can see now, they simply had the sparky change the end as long as the tool was designed for it and go to 30. Like I could find an unused outlet from another shift but it was all pretty random and never remember tripping up a circuit, like too many rod ovens etc, if there wasnt one convenient could always get a Y and insert it. Same for air, zillion T's and used a connector a size heavier than automotive, could always add a T in any live hose bout anywhere and never recall a demand issue.
At some level there must have been a demand formula to start with. I never saw how they powered it all, there were about 3 or 4 stations on each floor and simply plugged in with huge cable either polarity and went to a big resistor weighed 35# or so, lower the current the hotter it got.
Big azz smokin unit to weld itty bitty socket tube 3/8 and mini torch with 1/16 tunk. Air stations plumbed up similar and argon manifold and you found a line local and spliced on a Y if you had to with local flow meter.
 
My Bud said he bout died due to thinking the disconnect mounted on or near the machine, the only one in site was the disc and it was old and been remodeled, said he didnt think about it, turns out the real switch was on the other side of the wall and not in line of site etc and pow.
I didnt hit it but did that at a bar once, worked on this machine and had it all apart, put back together and the cook says, why doesnt the fryer work or something and had turned off the wrong breaker.
 
Great topic! To me, anything related to RF is especially interesting, because its behavior seems so different from the power frequencies we're used to dealing with. For example, here's a question that has always intrigued me: we know that radio waves transmit electrical power, because we can build a crystal set that actually converts that power into mechanical power - enough to vibrate the diaphragm of a small speaker and create sound waves. So, if we put a super-sensitive wattmeter on the transmitter at a radio broadcast station, shouldn't we see the power draw increase every time someone tunes a radio to that station? After all, that's how it would work if we measured the output from a power plant: every time someone turns on a light, we should be able to see the generator's load increase.

But it doesn't actually work that way. Unlike in a power system, the radio transmitter isn't directly coupled to the receivers. The transmitter does put out power, but its load is not the receivers in its listening area. The load is the transmitting antenna and ground, which in turn launch radio waves into space. And once those waves are launched, they have no connection to the antenna, so the transmitter doesn't "see" what happens to the waves, whether they get absorbed by a receiving antenna, or just go on forever.
 
AlbertL57 said:
shouldn't we see the power draw increase every time someone tunes a radio to that station?
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It's just like visible light, as well as all frequencies of the electromagnetic spectrum. You wouldn't expect a light bulb to dim or use more electricity, based on how many people are seeing the light. Or how many photocells turn that light into voltage :cool: nice one, btw.
 
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