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current control again!

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by plumber, Nov 4, 2009.

  1. kinarfi

    kinarfi Well-Known Member

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    Looked at the LM117 specs and 1.5 ma is below it's min current specs.
     
  2. Roff

    Roff Well-Known Member

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    I have never taken colloids internally (or externally), but a quick Google search seems to contradict this. Can you post a reference?
     
  3. plumber

    plumber New Member

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    Thanks for the challenge Roff but heavy metal poisoning is very well documented including gold. You are just looking in the wrong places. Instead of snake oil sellers, try biology etc. Too tired for this and still thanks for all your help. Plumber
     
  4. dave

    Dave New Member

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  5. mneary

    mneary New Member

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    oops. Good catch! :eek:
     
  6. syazzy17

    syazzy17 New Member

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    I am currently doing a project on current control and I have no idea what to do.....Can anybody help me......?
     
  7. mbarazeen

    mbarazeen Member

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    post your requirement in a new post explaining about the idea in detail, we are all here to help you.
     
  8. h2ovortex

    h2ovortex New Member

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    heavy metals and silver colloids

    "Heavy metals" is a vague and often misleading term. Gold and silver are categorized as transition metals, and may at times also be included in the "heavy metals" category, but the same applies to iron, cobalt, copper, zinc, manganese etc. All the latter ones are crucial for biological systems.

    Surely you can overdo on "heavy metals", like taking too much iron, zinc or copper. You can overdo on anything, like drinking too much water. Too much of anything makes it "toxic". The toxicity is then not related to the element itself, but to the amount you digest or apply.

    Also, colloidal silver does not make you "green" permanently. True, there is a condition called argyria, where the skin turns bluish, but there is great uncertainty and debate whether this is the result of properly made colloidal silver. Little research has been done on the rate of excretion of silver colloids after digestion, but one study found that a very high percentage (above 99%) was excreted after a couple of weeks.

    Some claim that silver salts may be the true reason for the very few cases of argyria that are known today. These silver salts may be the result of using salt (NaCl) to increase the conductivity of the water, to speed up the colloidal silver production process. And some claim that when Ag+ meets the stomach acids, lead to formation of silver salts. Anyway there are close to 10 million americans using colloidal silver on a regular basis, where most of them buy it in the health food store, so if this was really such a big problem there should have been hundreds of thousands of blue people today.

    Current limiting is indeed an issue with colloidal silver production. In the beginning the conductivity is very low, when using deionized water. The best is 18 Megaohm water, and at this purity water is very hungry for ions, and has great resistivity - in fact 18 megaohms/cm. As ions are sucked out of the anode, the conductivity (and current) rises until you reach the threshold - which is dependent on effective electrode area, electrode distance and effectiveness of particle dispersion (ions are indeed particles) to avoid current-increasing bridging. At this stage it is easy to see that "constant current" (as the silver generator producers often brag about) was a very difficult phenomenon at the very beginning, as conductivity was so low that it would have required thousands of volts to reach the threshold right at the start.

    As the conductivity of the medium rises above the threshold, the voltage has to be regulated down to keep the current constant. This is of course done by increasing the total resistance, which can be done in a lot of different ways. You can do it manually, by using a potmeter, or you can do it automatically using transistors or other circuits or even a microcontroller. You can even do it as simple as using a bulb in series with the electrodes, as the bulb filament increases its resistance as the current goes up.

    In addition to this you often want automatic polarity reversal, and you may like an automatic shut-off mechanism which gets triggered when the conductivity has reached a certain level, as conductivity in microsiemens is proportional with the ppm of the silver colloid by a factor of 1.6. By the way, a colloid is not a solution, neither a suspension. The best and cheapest meter today for measuring conductivity below 100 uS I believe is the PWT from Hanna. Using this you can calibrate your auto-shut off mechanism to the ppm you want, like 5 ppm. At a 5 ppm concentration, you can digest 70 milliliters of colloidal silver each day (if you weigh 150 pounts) before you reach the reference dose set by the EPA, which is the dose that even the most sensitive human being can ingest each day during a 70-year period without risk of any bad effects.

    I personally believe that the body has a use of silver, and it seems that the metalloprotein transport mechanism is able to take silver ions and bring them safely into the blood and deliver them to the place where needed. You can even use a nebulizer to deliver it to the lungs, and avoid the potential pitfall of the mixture with stomach acids. But if you are sceptical, as you should be, and still not sure about the safety of ingesting Ag+, you can always use it externally and in many other areas of life, like using it on your soil and getting it through the vegetables you eat. Silver has a very long tradition of widespread use, and it is only due to the destructive influence of big pharma that Ag+ did lose its premier position as a natural antibiotic in the 30's. But the times they are'a changin, and as bacteria gets more and more resistent to regular antibiotics, we end up back where we were at the beginning, with Ag+ as the true silver bullet against tough infections and even viral attacks.

    Making colloidal silver is not hard as long as you know the principles involved: pure water (10-18 megaoms), pure silver (99.95%+), and current control, which at the very least includes a particle dispersion mechanism and circuitry for current control. In addition to this, polarity reversal and auto-shut off are great, but not a must as you can monitor the process manually.
     
  9. syazzy17

    syazzy17 New Member

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    thanks mbarazeen...i will check about the details of the project with my leader and i will get back to you.....
     
  10. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Don't call the current limiter a diode. It is a current limiter made from a Jfet that has its gate connected to its source.
     
  11. syazzy17

    syazzy17 New Member

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    mbarazeen....i have the details to my project....

    3 components:power supply, current control curcuit and a potentiometer.

    when we supply the whole curcuit with 12v, we can control the current of the circuit using the current control circuit. at the same time, the voltage of the whole curcuit must not change....

    is it possible...?
     
  12. mbarazeen

    mbarazeen Member

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    you should tell more specificaly,
    1) tell where you are going to use it or what is the equipment to be supplied with constant current.
    2) the rating or the range of the current.

    when you say current controll the circuit will keep the current constant to the set value for variable load. thus the out put voltage will be adjusted by the current control circuit to provide the set current. selecting the right power supply would keep the imediate output of the supply not dropping bellow your required value.
     
  13. syazzy17

    syazzy17 New Member

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    we are supplying the the circuit with a constant 12V from a power supply. the output of the current curcuit is connected to a variable resistor and the output of the variable resistor is connected to the ground of the power supply.

    the range of the current is till 15 amps.
     
  14. syazzy17

    syazzy17 New Member

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    would it possible if you were to include a diagram of the current control diagram and its components as well?
    thanks.
     

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