12.10.07
Posted in Projects, Future Project Ideas, EFPD at 7:16 pm by philwinder
Just looking into some full wave rectification without diodes and I have so far found 2 ways. One with 2 op amps, quite costly, or one promising one with just a transistor:
I do like the look of this, might be right up my street. It does look slightly jubious, but its worth a try. If not, I might have to settle for the opamp rectifier.
Also found this, another opamp full wave rectifier but with the possibility of only 1 op amp. Even if it doesnt, it still uses less parts than the first.
Found one last one, much like the prebvious, but has some programmable gain on it.
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10.09.07
Posted in Projects, EFPD at 3:17 pm by philwinder
Long story short, I’ve finished my Masters (and got a 1st, yay!) a while ago now for which the EFPD was my final year project. It was this that boosted me to a first. 94% to be exact (in my project). I then went away working for 3 months and then went to Australia for a month and just before I went away, I was approached by someone that was interesting in buying the EFPD. Im now back and sorted and we are beginning to get things rolling so because I am selling all the rights to them, I no longer will be writing about it on this site.
That was actually a fairly long story, sorry! Long live the EFPD. (For my wallets sake!)
Phil
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05.14.07
Posted in EFPD at 5:54 pm by philwinder
Had the presentation today, went well.
More thoughts about the new circuit. Been looking at the low power side this afternoon, found a small CR2032 is a great sized battery at 20mm diameter and it does quite well at 220mAh. [1298246 FEC]
But I dont think that would be very good as a system. As a stand alone product, I should let the company worry about the power source, so I dont have to worry too much about that. More to concentrate on getting the power consumption down and providing a simple triggor solution all on one tiny chip.
So I have found an awesome amplifier to go for the 1 chip EFPD in the form of the LMC6044 with a 2fA bias current and 10uA/amp, only for £1.96 [9494626 FEC]. Just needs a power supply of 5V, and its single supply so I will also have to have a reference there.
Might be a nice idea to fit all this onto a card, or a big DIP package or something.
For a standalone product, the size doesnt matter as much becase a lot of the space will be taken up from batteries. Cost will take presidence here.
Finally also made a new filter (AGAIN) and this time its a 4th order with some cool standard components. It reaches about -65dB at 50Hz which is very good.
Phil
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02.26.07
Posted in EFPD at 3:39 pm by philwinder
Ok done the magnet tests to find what affects the system and came to the conclusion that it was both magnetic and electric fields that affect the device. So, im pretty much done, because we cant find a proper equation that works so I will have to just go on experimental data and form my own equation.
Also spoke to Wilkinson and I need to put an FFT on my matlab software and have a look at what frequencies I am working with. That means creating some excecutable to use on the uni computer, since thats the best enviroment to work from.
This also means that I really have to push the box machining to get it done asap. I will finish the threshold detector later…
Finally I need some pictures of the experiments for the documentation. So I will bring my camera in tommorow.
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02.13.07
Posted in EFPD at 4:57 pm by philwinder
New device reults taken x4
Old device results taken x2
New device from 5m, results show that it could go further with more gain.
The old device was from 3.5m was rubbush. The noise problem appeared on the first set of results.
Results from old and new device
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Posted in EFPD at 11:39 am by philwinder
Right, he loved the device, and I told him about the problems with the sound card. He said what I can do is to modulate the signal at a frequency that can be interpreted by the sound card.
He says I could use a 4066 chip which chops the signal into little bits at a frequency of say 4kHz. Check the schematic here.
Phil
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02.06.07
Posted in EFPD at 1:13 pm by philwinder
Heres some inked ideas that Dr. Paulson helped with.
Here
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01.29.07
Posted in EFPD at 2:50 pm by philwinder
Just found this ECG circuit. What was of interest was the filter on the inst. amp’s reference.
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