question about the Lewyt Electronic

[n0oxy]

I actually call this machine the zapper since it was known for shocking people, but I'm wondering what was different about the electric hose connection compared to most other electric hoses. Just about every other electric hose carries 120 volts and does not have this issue. I'm wondering what was different about the zapper that caused the problem when the rectifier failed. Did it actually use the hand grip to carry the current? Most electric hoses have the wires in the hose and it terminates in the receptacle that's on the handle. I think the hand grip is a separate part of the hose. Were their wires in the zapper's hose as well? I'm just wondering what keeps all of the other electric hoses that carry 120 volts from having this problem.
Mike

 

[kenkart]

The difference is

Not so much the hose, but the wands, one connector was a strip running down the inside of the wand, the other connector was...you guessed it,,,the WAND ITSELF!!! You were in contact with voltage anytime you were using it, so if there was a short, you got the full 120 volts!

 

[madman]

Neat. I suppose as long as your house wiring is correct, and the vacuum's plug is polarized (correctly), AND the live metal bits were on the neutral side of the wiring, in theory you'd never get shocked even if there was a short.

I wonder maybe if they did not have polarized plugs?

What's this about a rectifier though? Was it like... a DC motor that used diodes to rectify it?

Most grounded appliances with exposed metal bits are *technically* live anyway, as ground is also neutral, but again, provided house wiring is correct - in theory, again - you'd never get shocked. Because anything else you could touch that's live would/should also be grounded/neutral.

Also, getting shocked is always blown out of proportion.

 

[n0oxy]

the issue

If someone actually has the machine they could explain it better, but the design used a rectifier in the field coils of the motor that stepped the 120 volts down to 12 volts and that's what traveled through the hose and I presume through the hand grip, through the wands and in to the power nozzle. What would happen was, the rectifier in these machines would fail, sending 120 volts right through the hand grip, shocking the person who was using it, and probably destroying the power nozzle as well since it was designed to run on 12 volts. The law suits that resulted is what put Lewyt out of business. I was just wondering what keeps all of the other electric hoses that carry 120 volts from shocking anyone that touches them, but that's why I call this machine the zapper. Even when it was working correctly, it was probably sending 12 volts through your body, even though that's a low voltage, I still don't like that idea.
Mike

 

[madman]

Nah, you would still feel 12 volts, believe me.

So what I'm gathering is that the power nozzle used something like 12 volts, and instead of having an expensive transformer onboard, they did some weird electrical shortcut and used the motor windings. Very much plausible. Though to be fair, silicon diodes were pretty expensive in those days.

The thing is, in order to be electrocuted, you have to be touching TWO things at once. Perhaps the body of the machine was grounded and the wand - meant to be on a totally isolated circuit - when the thingy failed, put them on opposing ends of the same circuit? Idk.

Fascinating though, I would like to know more about how all that worked. I always liked examining design flaws. In this case, a failing at failing safe.

 

[collector2]

LOL to begin with it wasnt a rectifier. A rectifier only changes ac to dc.

The field winding of the motor had a secondary winding in with it. This, in effect, made the motor into a transformer as well. The 120V in the main (primary) winding induced a voltage in the secondary winding (24 volts I believe). As this created an isolated circuit the premise of using the body of the machine and the wand as a contact was sound. (In an isolated circuit you have to come in contact with both sides of the circuit to get a shock).

The problem came when people overfilled the bags, causing the motor to heat. The varnish insulating the wires on the field winding would melt off, allowing the primary and secondary to short together. This would charge the body / wand with 120V. If you were holding it and came in contact with anything that was grounded (sink, radiator, concrete floor etc) you got a shock.

Doug

 

[n0oxy]

thanks

Thanks for the explanation, that's the most detail I think I've seen on what actually happened. So it would only happen if the bag got too full. I wonder if you wore rubber gloves if you would be safe. I know the law suits that resulted from this issue put Lewyt out of business. I wonder what keeps all of the electric hoses that we use now that carry 120 volts from having this issue.
Mike

 

[madman]

Collector2 - now THAT makes sense. I'll bet though that the motor wouldn't act so much as a transformer as a generator. But same difference.

n0oxy - I'm pretty sure most electric hoses don't have any exposed metal parts that are grounded (part of the circuit) and just use two wires that are insulated normally.

 

[collector2]

Hey Mike

It was more an issue of the bag being constantly overfilled so the motor was run hot on many occasions. In retrospect, either better insulation or the addition of a thermocouple that cut the motor out when it got too hot (like new machines have) would probably have avoided the problem.

Present day electric hoses use two electrical connections rather than using the actual handgrip as a connection (as Lewyt did) so you dont have the problem of coming in contact with power.

And yes, I have seen several machines that were taken care of and not overheated. They still work perfectly.

Doug

 

[n0oxy]

hose difference

Ok, I think I understand, most electric hoses use two wires within the hose and the current terminates in the receptacle, where as the Lewyt machine used the hand grip itself as part of the electrical connection, do I have it right? Even when it was working properly, if you touched something that was grounded, you would still probably get a low voltage through your body, there's something about that that rubs me the wrong way. Since it was low voltage, I'm wondering how well the power nozzle actually cleaned.
Mike

 

[collector2]

Hey Mike

Actually no - because it was an isolated circuit (aka no part of it was supposed to be grounded) you would have had to touch both the handgrip and the connecting wire to get even a low voltage shock.

Doug

 

[n0oxy]

testing

I guess this issue never came up while they were developing it, it only happened once people started using it. I can't help but wonder if it only caused a shock or if anyone was actually electrocuted and killed by it. Apparently they are good cleaners other than this problem, wonder what other cleaners they would have come out with if this had not put them out of business.
Mike

 

[huskyvacs]

The only way to find out I guess is for someone to test it with a multimeter and see how much voltage actually goes through it?

Also I am not sure if these vacuums were advertised as wet pick up (I see a lot of them rusty inside on online photos). If they were advertised as wet pickup like a shop vac, with this unique shock hazard on the handle, and you're standing on a wet rug holding the handle, it would be curtains for you.

 

[kirbyvertibles]

I have 2 of this variation and both still work great.
They aren't for wet pick up. Most likely the reason for the rusty inside is being stored with a full bag in a damp dark closet,basement, garage etc.for 40 years

 

[kirbyvertibles]

They should have stuck with their first one with the corded power nozzle but unfortunately they got to fancy for their britches and the rest is history.

 

[collector2]

How much of a shock you got would depend on a number of factors. Where in the winding the short developed, how well grounded you were etc. I have never heard if anyone was killed but it is possible as you are holding the handgrip in one hand and, should you touch something, like a sink, that is well grounded with the other hand the power would be going across the heart. As far as I know though the majority of the people just got shocks. Of course everyone has to jump on the band wagon and try to get something when there is a lawsuit.

 

[dirtmaster37]

Carl Meyerhoffer, the brain of "Lewyt Electro-ni-cuter&#

In a previous thread about the Lewyt Electronic, there was a post, from Aeoliandave (sp), containing the legal patent papers he had found, and posted up then. These "papers" are what was filed with the U.S. Patent offices by Carl, thru the Lewyt Corporation, to explain what HE "invented", and to summarily keep others from "stealing" HIS/ Lewyt's idea.. In this text, with detailed, engineering/ engineered drawings, explains, in the greatest of detail, the actual workings of this (non-electronic) wonder cleaner. So the WHY's and HOW's of the Lewyt Electronic if you will.

So-

Carl Meyerhoffer's thinking, was that a secondary winding, properly insulated by a varnish from the iron stator..i.e lamination's in his words, held water to create the step-down voltage required to make his contraption work.. His views were supplanted by his carefully worded text, which only cast out a possibility of trouble AS LONG AS the metal wands and hose hand-grip did NOT come into contact with any other metal surface that could constitute as a ground. Possibly later, the heat of the motor was a trouble spot, as Doug from Canada, and others have suggested; but it wasn't mentioned in the 1961 patent information. Ironically, by the date on the patent paper, June 13, 1961; the Lewyt Corporation was pretty much dead.

In Most NORMAL operation, he goes on in technical mumbo-jumbo, to explain that the step-down circuit shouldn't or should NOT come into play with any ground; while said machine was running. Meyerhoffer in jargon filled patent papers ambles up to this point about 35,000 words in, it seems.

Ones understanding of that text, that, if the latter DID happen, it "could ground together" the primary and secondary winding's. And, POSSIBLY, MAYBE could caused an electrocution to happen. The text chooses NOT to clarify if it was an immediate possibility, or within a few moments, or at all. Just that it COULD happen. So, as the varnish used to isolate the two fields started to melt off, thats when the danger happens..Only after a few more words of jargon does he intimate that it WAS possible that your vacuum would then be sending 110v out the metal parts; straight up into your body. This issue could be compounded even MORE SO if milady or miseuer happened to be grounded in some way themselves. Again touching a water pipe, anything that COULD ground ones person.

In the text, it say :such as touching a water-pipe, a stove, something metal anyways. RIGHT THERE IN THE TEXT.

I have searched the internet pretty thoroughly, when one get into a sleuth y, historian minded mode; and, have YET to find any published article, or support that any such deaths from said electrocution existed. That said, it clearly happened. Lore of a thing/item or person rarely happens overnight, or stays consistent for nearly 6 decades now. I mean, ask anyone who has an Edsel.

In the late 1950's, there were few if ANY consumer advocacy groups. Class-action lawsuits weren't even heard of (not that they didn't exist), and certainly the media insulated us from such things usually. Also, the incidents were decades away from easy to orchestrate, public/social media blasts so common today.

Moreover, something WAS big enough to bring Lewyt down, to bee sold off in part, to Shetland in 1962. So, does anyone out there actually have "some" printed proof of the lawsuits, and deaths? Please bring forth once and for all!

I have seen finally in person a Lewyt Electronic,at a recent vacuum convention, owned by Kirbyvertibles, who has added to this thread. His works properly (not in pieces), or had the circuitry snipped out inside the cleaner to undo the circuits that clearly failed previously.

It's living proof, that in a different time, with better ACTUAL electronic circuitry it probably would HAVE worked, SAFELY. It is, in fact a marvel of it's time, so long as ALL the connections were tight and the motor step-down worked properly. You have to admit tho , it solved a real problem that still exists to this DAY, meaning having to engineer a complete 110v circuit for every canister-upright/power-team that is extant.

And so on the Lewyt Electronic goes....

http://

 

[n0oxy]

very interesting information

Originally I had thought that all of the Lewyt power nozzle models were zappers but I guess the original one was not, was that one even called an electronic? It sounds like the developer was aware that the issue could happen but didn't think it would. If that happened today the company would probably end up issuing a recall. If there were really enough law suits to put the company out of business, the issue probably happened on quite a few machines. I would love to try using one just to see what it was like, as has been previously stated, if they had stuck with the original design the issue never would have happened. They were probably trying to make things easier by removing the external cord that had to be connected, and of course, around the same time the Kenmore canisters did come out with the electric hose that carried 120 volts. Lewyt can still claim credit for introducing the first canister type cleaner with a motorized power nozzle.
Mike

 

[madman]

I'm still a little unclear as to whether that would be a motor-generator, or a motor-transformer. By the schematic, I'm leaning towards transformer. But either way, it seems like a clever way of lowering manufacturing cost. They were winding the motor already, they just add a little extra, as opposed to either making or buying a totally separate transformer.

Speaking as someone who's been electrocuted more times than I can remember, nobody died from that, unless they were an elderly person with a heart condition. I've been zapped even arm to arm several times, it's harmless. Pretty much the only way 120vac could kill you is if you make toast while taking a saltwater bath. Or, you know, sticking electrodes into your heart.