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LAN_403

Mates

Sat Jan 05 2008, 02:05AM

Registered Member #1025 Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566

CT2 wrote ...

Mates I think you need to calm down, I realise the majority of people are stupid, but that doesn't make me responsible for their safety. That said I wasn't the one who suggested hooking up a MOT to a fence, infact I said it wasn't a good idea, even if it was in a slightly sarcastic manner. Then you go on to say that he should hook up an iggy to the fence? I doubt that is a good idea either and could get him into trouble. But this topic isn't about electric fences it's about what he could use the parts for, so no don't use the MOT to build a fence.

Yeah, I little bit overreactedâ€¦
I was burned once quite seriously by MOT when I used it for a simple CW multiplier based on ceramic caps and got a great idea to check with my finger whether the caps are getting hot. I pulled maybe 6cm plasma from the cap straight into my finger. I lost big piece of flash during next few days and it took many weeks to healâ€¦ Exactly this story came to my mind when I red the stuff with the MOT based electric fence.
Take it easy...

Steve Conner

Sat Jan 05 2008, 01:52PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

See

for disclaimers.

In other words, if you follow some advice you read here and kill yourself, it's not 4hv.org's problem!

When doing experiments, your health and safety is *your* responsibility. And don't touch a MOT while it's turned on, it carries a serious risk of death!

Andyman

Sun Jan 06 2008, 03:28AM

Registered Member #1083 Joined: Mon Oct 29 2007, 06:16PM
Location: Upland, California
Posts: 256

Build a horn antenna for the magnetron probe and set it up so the MOT runs off of a power inverter in your car. Then you can disrupt the stereos of those people blasting their annoying music. Or just use it to light up fluorescent light bulbs wirelessly for a magic show.
Or just give yourself cancer...

teslacoolguy

Mon Jan 21 2008, 07:00PM

Registered Member #1107 Joined: Thu Nov 08 2007, 10:09PM
Location:
Posts: 792

i like the car stereo thing i should make one and put it on the roof so when some person is blasting there stereo at 3am like they do were i live it will teach them a lesson

Tesladownunder

Tue Jan 22 2008, 03:49PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Having scrapped 12 MO's in the last week, I feel able to comment.

There are a lot of parts for the scrap box. A sample

Fan: use as a fan or knock out the core of the little induction motor and you have a useful coil of thin wire which I use for my lifters.

Globes: These are low wattage and quite handy to wire into any HV circuit that runs off the mains so it lights up when it is on. A very important safety measure. A few days ago I wired one across a MOT being used as ballast and it glows when the load is on. A useful simple current indicator.

Platter rotation motor. Facinating things and also has a coil of ultrathin wire. I use one as a magnetic pick up. Will light 2 LED's when a magnet is passed through. The 5 RPM motor may be useful in its own right.

Thermal cutouts. Usually a couple in the oven. A good idea to wire them into any circuit that might get too hot. There are humidity sensors in some of the older ones.

Mains cable

Mains supression board is useful for equipment you make. The toroid core can be used in a ZVS circuit.

Capacitor. 1uF 10kV with bleeder. Use as a voltage doubler as in the MO but this can also be extended with other caps and diodes into a CW multiplier. I have a multiplier that runs 4 MO caps then lots of smaller ceramic stages. Diodes are 1N4007 strings and the peak voltage is close to 10kV. It will initiate the arc at 10kv but still run a high current into an arc. Need a hefty series resistor but mine has been rock solid and I use it often. Banks of these caps can even be used for can crushing if you have 18 or so.

MOT: I have used one as a ballast for another MO to draw arcs. I have used 4 in a TC supply. I have used them for an E core electromaget (grind off the weld). Cut off the HV windings and put in half a dozen turns of very thick wire and you have a valve filament supply or a mini spot welder.

Wire with spade connectors.

Glass panel from front door may have some uses.

Microswitches

Magetron. Pull the magnets out, get some bismuth and a little cube NIB magnet and make a diamagnetic levitator. Grind it open and learn how magnetron works.

The MO case is an excellent project case with supply already built in. I have used several like this. Eg for a TC supply.

HV diode. Useful for voltage multipliers if you have enough. There is often a fusible diode there as well. I dont know much about these.

HV fuse in some units.

The electronics board. Has a relay and a piezo buzzer. Never found a lot of use for these bu you may if you make a bit of smaller stuff.

So lots of stuff to potentially use or add the the scrap box.

If you run out of ideas you can really stretch you brain and make a TC completely from the parts of one MO, adding only solder and hot glue

TDU

Mates

Tue Jan 22 2008, 05:29PM

Registered Member #1025 Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566

Andyman wrote ...

Or just give yourself cancer...

I've never red any study showing mutagenic or carcinogenic effect of HF (GHz) field. The only thing which threats is burning your eyes (they are full of water) and gets blinded. Anyone working with the magnetron should be aware of the risk it has for your eyes! Alternatively you can burn your skin, but usually the pain sends you away from the danger long before something really bad happen.

Anyone can argue about cell phones and cancer (there are some statistics suggesting this correlation). If there is any direct physiological effect of HF from this devices leading to cancer, than is it the heat which gets generated in your brain cells, and potentially can trigger some inflammation like responses. It was shown that chronic inflammation focus in your tissue can increase the risk of cell transformation and we can speculate that overusing of mobile phones can mimic this effect. However, there is no study proving it - so it's only speculation and you can still switch between the ears and cut the risk by 50%

Cheers,
Mates

Proud Mary

Tue Jan 22 2008, 06:38PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Beryllium oxide (BeO) may be present in structural ceramics in some magnetrons.

BeO is a potent carcinogen, and even a single exposure to BeO dust or powder by inhalation can sometimes cause berylliosis.

So best not go bashing up the magnetron with a hammer, or doing anything that might break up the ceramics and turn them to do dust.

Tesladownunder

Thu Jan 24 2008, 05:03AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

I wasn't aware of BeO in Magnetons although it is used a lot in argon lasers.
Wiki says the pink ceramic contains BeO which is probably most of them around here.
Berylliosis is a fibrosing disease and we are all very scared of it. Put it in perspective that talcum powder is also a fibrosing agent (which I have used medically) and deaths in babies have been recorded when they inhaled it when it got spilt on their face. The single dose cancer effect sounds a bit speculative to me (very hard to prove things like that) although no doubt chronic exposure is a risk factor.

TDU

Proud Mary

Thu Jan 24 2008, 03:09PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Sendelbach LE, Tryka AF, Witschi H.Progressive lung injury over a one-year period after a single inhalation exposure to beryllium sulfate. American Review of Respiratory Disease. 1989 Apr;139(4):1003-9

Tesladownunder

Thu Jan 24 2008, 04:14PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Harry wrote ...

Sendelbach LE, Tryka AF, Witschi H.Progressive lung injury over a one-year period after a single inhalation exposure to beryllium sulfate. American Review of Respiratory Disease. 1989 Apr;139(4):1003-9

I haven't been able to get that article to determine the dose and circumstances of that single intake and whether it was a single breath or a one day exposure. Some of Sendelbachs mouse studies used exposures of 1 hour at a defined dose. He used the soluble beryllium sulphate which is different to the more inert insoluble BeO as present in magnetrons and other common objects such as spark plugs.
In terms of grinding ceramics, there have been cases of chronic Berylliosis in Ceramic factories (in Japan for example) but this is in manufacture.
Almost all berylliosis cases have been occupational exposures.
The cancer risk is present but minor and was not formally accepted until 1993 so was quite difficult to prove.
I see little evidence for significant risk of a brief grinding of a magnetron ceramic in a well ventilated environment (outdoors) using a mask.

TDU

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