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Alex Tsekenis
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Posts posted by Alex Tsekenis
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It is interesting how terms are misinterpreted across sciences.
Anyway, so the photoelectic effect will change the conductivity of your compound, so you should be able to measure that with the electrodes.
Is that what you are after? You mentioned 'circuit' in your first post? -
I see...You could have the crystals/polymer deposited on an electrode and then form a near-uniform electric field by placing another electrode opposite to that and connect that to a high voltage source. The electrons freed will be accelerated to the anode. You can then put the assembly in a vaccum chamber and your goal would be to measure the current between the electrodes with a ridiculously sensitive and low-noise meter.
The technique with the two conductive plates sounds very familiar is that like electrophoresis used in biosciences?
Your material will be locally ionised, would it not? If you have the crystals embedded then it would be a very near uniform ionisation. I reckon you got yourself a conductor as the electrons are free to migrate. So maybe this is different to electrophoresis.
Again, it comes down to measuring tiny currents. But first we need to know what to expect from theory. I could ask my brother if this is electrophoresis in its pure form, he should know more. -
Wow. I hope no such "audiophile" falls in your hands :o
I couldn't agree more, I mean who cares about the fifth harmonic which will be better filtered by the bypass capacitors anyway. One of the extremes I have seen (can't recall where, prob some advert) is a silver/rubber ring to put around valves that "reduces noise and distortion by allowing electrons to travel smoothly from cathode to anode". ???
Regarding batteries, they will have lower noise than any regulator, no matter how good it is. However, as you said, their high internal resistance makes them a bad choice for hi-fi audio. -
Hero, by total nonsense are you referring to the fact that some people use batteries for their audio amplifier? From your post it looks like that.
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I know some audio purists (also go by the name rich idiots by other people) use batteries to power their tube audio amplifiers. It is true that batteries will have lower noise than any other source. Adding a linear regulator will add more noise. Switching to batteries will be my last optimisation step in any audio project.
Not sure about the 5th harmonic as you say, could be anything, maybe your PC's power supply? Who knows. How big is it? Post a graph. -
You really think I was asking for a definition?
What I meant is, do you want to scan the polymer with a probe? Do you want a quantitative measure of current or some comparison method? What source of light source will you use? Do you have a vaccum chamber? -
In what sense do you want to access the polymer?
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Please tell us,
What is your technical background
What do you mean by power electronics
What will the book be used for
Regards,
Alex -
I am surprised that they put an expensive (for Chinese product standards) DIP package for the controller. Usually it's a COB.
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The next question will probably be: "I've built the circuit using a 6VAC adaptor but the output voltage drops when a 1A load is connected. What's wrong?"
Keep your patience Hero. ;D -
I assume you can learn the thory somewhere else, so to summarise what has been said, no you will not burn your regulator because your trafo is 1.5A rated, assuming your circuit uses less than 1.5A.
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It is so annoying, these Chinese-made devices with non-standard part numbers.
Anyway, apparently the PCR606 is a thyristor in a T0-92 package with the following key specs:
V(DRM): : 400 v
V(RRM) : 400 v
IT(RMS) : 0.8 A
I(GT) : V(AK)=7V
Max IGT=200 uA
V : 1.7 V
Try this:
http://uk.farnell.com/nxp/bt169d/thyristor-0-8a-400v-to-92/dp/1510734
Regards,
Alex -
Sounds like a typical project specification. "We want a device that does everything, we will tell you new requirements one day before prototyping, it needs to be smaller than a matchbox, have zero power consumption, we want it yesterday, and for free."
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bugmenot,
Here is the reply that I received:
Dear Alex,
Most modern DSP platforms will support the kind of system you wish to interface. Take a look, for example, at the low-cost TI DSP platforms which are also supplied with Code Composer Studio. However, in order for me to give a definitive answer, I would need to know your data rate, the kind of processing you wish to perform and the interface configurations.
Best wishes,
Patrick.
Let me know if you want me to ask him anything else.
Regards,
Alex -
Hi,
How much power do you want the converter to be able to give you? What are you going to power with it?
Regards,
Alex -
Hi,
Could you please post a picture of the actual components?
What is this exactly? I can't make much sense from the drawing. Did your 220 to 110 V converter break?
Regards,
Alex -
You need to tell us exactly what you are required to do Oguz_ehm.
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The ammeter does not really require any resistors to work. It can be just a piece of wire.
You might need resistors to increase its range.
Another thing you can do is buy a ready analogue volt meter and connect it across a resistor of 1 Ohm.
Then the display will be in Amperes. See diagram attached and link.
http://uk.farnell.com/tyco-electronics-crompton/e242-89v-g-mt-mt/meter-din48-10vdc/dp/1227831
Moving coil or moving iron meters can only measure current really.
Regards,
Alex
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Ok. Very surprised they asked you to build an analogue current meter at college.
Is it for DC or AC? A simple current meter could have a coil of wire and a needle attached on a magnet.
http://isaac.exploratorium.edu/~pauld/summer_institute/summer_day15current/ammeter.html
http://chestofbooks.com/crafts/popular-mechanics/The-Boy-Mechanic-700-Things-for-Boys-to-Do/How-To-Make-An-Ammeter.html -
You need to tell us more about your project. Do you need to build an analogue current meter yourself? Buy one?
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What are you required to do in this project?
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Good, glad you are getting your head around this.
These platforms are very powerful not very different than a normal PC or laptop.
Anyway, a friend of mine, enthusiastic about DSP, suggested Texas Instruments as a leader in DSP platforms. Have a look at their DSP portfolio.
FPGAs. Unless you have a very good reason to change your processor architecture in the future, dont use them. The development cycle is overwhelming even if you use C-to-hardware compilers, say in Altium Designer.
Operating systems. If you use the DSP processor only as a workhorse you might not need an OS on the DSP itself, you can have say a small ARM-based system which runs the OS and controls the I/O.
Make sure you can run Duke Nukem on your platform. Great added value while the blimp is grounded. I also see how this can also be useful to spy on ones girlfriend/boyfriend.
Expert advise will come in early next week, I think.
Regards,
Alex -
That's a great 'poor-mas' sensor idea. Thanks for sharing.
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R66 is the name of the component as far as the schematic is concerned. R66 means that this is a resistor, number 66 on the schematic.
Where did you get R22 from? That is clearly R66.
If your component was not there initially then you should not place it because it is missing! Sometimes, it is useful for a manufacturer to have space for some components on the board that are not normally populated. This way they can change the specifications of the products by playing with those components.
Not sure where you got 66mA from, it really is irrelevant here.
Regards,
Alex
precision photoemission assessment.
in Electronic Projects Design/Ideas
Posted
Do you mean decimal points? That is a lot of precision...
Have you looked for any "schientific" instruments for this purpose?
What conductivity values/range do you expect?
I dont recognise the term avalanche effect, what exactly do you mean? Maybe a process similar to avalanche breakdown in insulators/semiconductors?