Does anyone know how this thing works?

Initially I thought it was a hard drive muncher but realised it's age and it's most likely a video tape eraser of some kind..

What makes it work? would there be any spent nuclear fuel rods inside or something crazy like that?



Do not wear watches? so it must omit magnetic fields when in use?



Instructions.





It's a heavy wooden box, about 40 kg's so there much be something interesting inside to weight that much, could it be just a transformer?

What would this fit into? like what kind of enthusiast would be interested in something like this?

Thanks.. Ben

Bulk erasers were used by radio stations, recording studios, etc, to erase magnetic recording tape of the type used in reel-to-reel recorders, e.g. :

http://thumbs.dreamstime.com/z/stereo-reel-to-reel-tape-deck-player-recorder-22818402.jpg

The slow way to erase a tape involves running every inch of it past a permanent magnet. The quick way is to pass the whole tape through a strong electromagnetic field and it zap it in the one go. That's bulk erasing.

Richard Nixon was very familiar with this process.

Big strong electromagnets in these things. The two main benefits are that you can pretty much guarantee the destruction of any material that is confidential. It is also more productive than feeding cassettes and reels (video and audio) through their machines recording blank signals over what you want to erase. A few seconds vs three hours. This method also saves wear and tear on the tape.

They'll erase all types of magnetic tape. Reels, audio cassettes, video tapes, Revox cartridges, Betacam cassettes and many more.

I wouldn't be too keen on operating these machines if I had a pacemaker though.

Thats what BBC used to get rid of Doctor Who episodes years ago...

The tape head demagnetisers turned a magnet full rotation alternating poles as it was played.
I'd be interested to know if the device has any rectifier behind whatever coil it uses.
You can feel the vibration when holding a magnet near a power transformer, I wouldn't be suprised if they were using AC to do the erasing.

I couldn't tell you what a rectifier was if one was up my own
but I did open the unit up to have a look, the pictures are too big to post here but it's quite a different transformer than what i'm used too. Maybe you can tell me what the 4 cans of red bull are for?

http://scrapforum.com.au/recycling-commercial-ewaste/4916-scrapping-a-weircliffe-bulk-eraser-model-8

They are capacitors (condensers in vintage radio parlance). They store an electric charge, a bit like a battery but they discharge fairly quickly. They are often used to filter AC ripple out of rectified current flows.

BTW: URL tags don't work here, so I changed them to IMG tags.

Oh ok, yeah i'm familiar with larger capacitors in mirowaves etc and the general idea of 'em, got confused as there's 4 and thought it might of been, oh I dunno what I thought really .

The four capacitors are most likely for power factor correction. Having a massive inductor like this hanging off the domestic mains without PF correction is not a good idea.

The ABC had these, too, for erasing audio reels and the Cuemaster endless loop cartridges they used for news grabs and sound effects. One of my jobs as a trainee.