Project help

[craighome]

I have a requirement for a project to switch a 4.5V battery supply between negative and postive after a 15 minute timer interval (note the original diagram listed 5 sets of 2 batteries = 3v but it's now 3 sets of 3 = 4.5v)

Just wondered what would be the best way of achieving this as I probably need a DPST relay and a timer.... any ideas of a existing circuit I can use?

I am trying to recreate this project:

http://www.comsci.org.uk/images/aura%20b%20pcb%201.jpg

**broken link removed**

Any help appreciated as looking to build a few

many thanks

 

[microtexan]

Me believes that "Crock" is a most appropriate name for this device!

 

[blueroomelectronics]

Yes steaming crock more like it.

 

[leeryjay]

i have a project of design a moving message display with a pre-selected words.please help out with any information

 

[Mr RB]

Yep, I remember this picture, the old "just connect to one terminal of the battery" trick;

**broken link removed**

 

[microtexan]

Crock

i have a project of design a moving message display with a pre-selected words.please help out with any information

What does this have to do with the original post (OP)

 

[KMoffett]

microtexan,
I think you are looking at the wrong thread.

Ken

 

[Noggin]

OMG why do you people jump to conclusions about this medical stuff saying that its stupid? Do you guys even understand EMI fields or just pretend to?

The device creates openings in your body by stretching holes in your tissue which allows contaminants to pass through more easily. Imagine a sheet of rubber with a tiny hole in it. Now, imagine that the rubber sheet has some sand on top of it. Only a few grains of sand can pass through the hole because its too small right? Now, imagine if you were to grab opposing sides of the rubber sheet and STTREEEETCH it out!

What just happened???

A bunch of sand fell through the hole as you stretched it out!! Eventually though, everything settles into an equilibrium and the sand quits falling. So now you have to grab the other two sides of the rubber and and give those a pull.

WOO HOO!!! Bunch more sand just fell through the hole!

Keep doing that and all the sand will make it through.

So, what on earth does this have to do with the circuit the OP posted!?!? Well I'll tell you... The circuit makes a magnetic field, which tugs on the iron in your body, which in turn tugs on your tissues! As the iron gets tugged around, it creates tiny tiny holes for tiny tiny contaminates to pass through. Eventually, all the iron gets lined up with the magnetic field lines though so you have to change direction.

If you don't understand this, go grab a high school physics book. If you still don't get it, go hang out at car forums.

 

[arunb]

The circuit makes a magnetic field, which tugs on the iron in your body, which in turn tugs on your tissues! As the iron gets tugged around, it creates tiny tiny holes for tiny tiny contaminates to pass through. Eventually, all the iron gets lined up with the magnetic field lines though so you have to change direction.

Technically that should be possible...in fact MRI-Magnetic Resonance Imaging works on that principle, but then you would have to generate a large amount of magnetic field (or Flux) to re-create that effect.

I don't think skin can stretch due to magnetic force.....its more 'junk science' than fact

 

[Noggin]

Well I wasn't in the least bit serious

 

[2camjohn]

Haha Noggin you suckered me in to a half page rebuttal...
Glad I read the replies before posting it.

Sorry not been a forum regular for a while...




These kinds of alternative therapies really annoy me. Especially the ones using magnetism and electricity.
They use electronics as the black magic that makes it all work.

Which makes these therapies plausible for someone who doesnt know a thing about elecronics or physics.

Nobody steals our credibility and gets away with it...

 

[Mr RB]

OK Noggin, while you're on a roll, explain how connecting to just one side of the battery works...

**broken link removed**

I've got a lot of battery operated devices I wand to run like this, I figure if they can be made to work with only one side of the battery connected it *should* reduce battery drain!

 

[Noggin]

Oh Jesus RB. I thought you were the Roman Black! This one is so obvious. Did you not see the text "new single wire method using body as "floating ground"?

Ok, well here's the explanation: The human body is slap full of iron, which makes a person essentially a huge capacitor. There is no complete loop as in conventional electronics, but despite that, the batteries do have to do some work to change the potential of the human capacitor.

This reminds me of the video I saw a year or two ago of the very high voltage line testers. I believe the lines were on the order of 50kV DC. Guys would fly up to the lines sitting on the side of a helicopter and hold out a metal rod to charge the helicopter up to the same potential as the line before touching it. Although there was no loop, it still had to charge the heli up like a capacitor.

Same situation here, the human body has to be charged up, and it takes a long time to do it because the capacitance increases and the iron in the body aligns with the manetic field lines.

 

[Mr RB]

Man now you are getting too subtle. You actually sound serious!

 

[Noggin]

I try to add enough words so that if someone knows just a little bit they might actually believe me. For instance, on a car audio forum some people got into an argument about how someone ran some speaker wire. The guy's wires was a good 10 or 20 feet too long, so he just coiled it up and stuffed it under his rear passenger seat instead of cutting the wire to the proper length. Some of the guys on the forum tore into him saying it was a bad idea and could cause problems. When pressed for what the problems were he said he didn't know, just that it would cause problems. So I chimed in and started talking about electromagnets (something just about everyone has played with or read about) and how they have the wire coiled around them. Convinced them that without a core for the magnetic field to form in all the electrons slow down in the wire and dissipate heat because they can't organize properly. Since he had a "high power system" he was in danger of melting the foam in his seat and making his car smell bad.

I also convinced one person that lobsters are magnetic. They have a lot of iron in their shells which is why they are rust colored.