***Official Electronics Thread of Officialness (it starts off with lots of Nixie Tube Clock goodness

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dirtychinchilla said:
Very good. The supplier doesn't have any info on it unfortunately. The datasheet they've produced for this item is crap.
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I've not built mine yet as you can see in the picture so I'm not sure. I do know the circuit and LCD will run from 3 x AA batteries though... Remember these chips require a voltage between 2.1v - 5.5v
 
Alright, that's good enough for me tbh. Worst comes to the worst I'll pay for it myself. Thanks a lot for your help Lakeland, I really appreciate it. I'll be going through the PickAxe forums for help with the program. Wish me luck!!
 
dirtychinchilla said:
Alright, that's good enough for me tbh. Worst comes to the worst I'll pay for it myself. Thanks a lot for your help Lakeland, I really appreciate it. I'll be going through the PickAxe forums for help with the program. Wish me luck!!
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Good luck mate, make sure you post back with your results, it will be interesting to see how you get on.

P.S. it's called 'Picaxe', using that when searching might get you more results :)
 
http://www.wired.co.uk/news/archive/2012-03/09/230-percent-efficient-leds

MIT physicists have managed to build a light-emitting diode that has an electrical efficiency of more than 100 percent. You may ask, "Wouldn't that mean it breaks the first law of thermodynamics?" The answer, happily, is no.

The LED produces 69 picowatts of light using 30 picowatts of power, giving it an efficiency of 230 percent. That means it operates above "unity efficiency" -- putting it into a category normally occupied by perpetual motion machines.

However, while MIT's diode puts out more than twice as much energy in photons as it's fed in electrons, it doesn't violate the conservation of energy because it appears to draw in heat energy from its surroundings instead. When it gets more than 100 percent electrically-efficient, it begins to cool down, stealing energy from its environment to convert into more photons.
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Interesting.
 
Been reading up on synchronous motors (or alternators depending on how you look at it). Say if i had a four pole motor, would the two opposite sets of poles have to be independently powered? With a waveform exactly 180 degrees out of phase with the other? Or could you just feed them all with the same wave?

It seems that the rotational speed is a function of the number of poles and the frequency of the AC current. And the torque is a function of the magnetic field strength. I can calculate speed based on reverse-engineering a few figures i found in an article (2 pole @ 60Hz = 3600rpm), but how do you know how much torque you need? Say i wanted to move a 1kg load at 60rpm, is it basically just trial and error?
 
Torque=Force*Distance.
iirc RPM is just related to the frequency of the AC current. So with a four pole motor, you will need 4 phases, each phase 90 degrees out of phase with the next pole in rotation.
We only briefly covered this in A2 physics, we did not even talk about torque.

I am now deciding between Bristol & SOTON for EE/EEE. Really hard decision :(.
 
Hmm, well the article i found seems to think that the number of phases doesn't have to be equal to the number of poles. For example, it has this:

P6BqF.png

Which it labels as a three phase four pole motor. My guess is that it will work as long as you have more than one phase? It seems you could generate a sine wave by spinning an alternator with just one phase, but you couldn't spin a motor with the same configuration? Although that doesn't seem to make sense.

My head hurts :p
 
Makhaira said:
Arduinos in particular, no, but I've done a fair bit of microprocessor programming (did my dissertation in it) - what's the issue?
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Hi, thanks for the offer, I actually managed to sort it late last night! I'm hoping to finish it off today so I might post it up in case things could be simplified or made more robust.
 
Need your help. My GCSE electronics was a long time ago.

Im working on a project and looking to be able to make a simple 555 timer or buy a kit pre made that will triger every 7 too 10 seconds.

It's to operate a camera, well 4 + of them all at the same time.

Reason for it is it's small, cheap as chip, light weight and pretty much okay with the cold, -40c at least
 
-40 degrees? How are you going to power it? Sounds like you're after a Astable circuit? Depending on how you are linking to the cameras it may well be better to do this with a micro controller
 
Lithium battery. Plus the items will be wraped in foam to insulate and a heatpack to try and help boost temps. Along with the box thats insulated.

It's been done lots and works.

The camera is a push to make switch so the output can fire across that.

If i said im going to 100,000ft you'll have a small idea whats being planned here!
 
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