Announcement

Collapse
No announcement yet.

super efficient exciter circuit

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Originally posted by gyula View Post
    Hi Jaskro,

    Just take your time as most convenience for you, no need for any hurry.

    On super capacitors: unfortunately they are expensive indeed and the cheaper ones like Coin or Button shaped ones with 5.5V or 5.7V max DC voltage ratings are intented for memory backup purposes and have inner resistances (ESR) in anywhere in the 5 to 30 Ohm range (!), these are not good for your present application. Any decent super cap or ultra cap have a data sheet which includes ESR values at DC and in the kHz range and you wish to choose in the some milliOhm to some ten milliOhm range, that would be already good for this exciter. The only problem with them is the max 2.7V DC voltage rating and if you connect say 6 of them in series you are still at the 16V value but with 6 times higher inner resistance. So a good compromise is to be taken if possible.
    IF you search on ebay, you may find some useful looking offer:
    10PCS 20F 2.7V KAMCAP Farad Super Capacitor Ultra Capacitor Power | eBay

    Say a 3 terminal regulator IC like 7815 or 7818 is able to operate your present setup under the 10mA load current while you can still estimate the power LEDs give some 3-4W light output as from the power supply then it might be worth buying the above 10 pcs 20F supercaps and run the exciter from their series connections via the IC regulator.

    There are supercaps for car audio applications (for HiFi funs with thick purse) but here is a used 3F (probably 16V rated) supercap offer:
    STINGER SSCAP3 3 FARAD CAP CAR AUDIO SUPER CAPACITOR, | eBay Data sheet is needed to learn about the inner resistance, normally the higher than 2.7V rated supercaps are manufactured from several 2.5 or 2.7V types combined in series to get the 13.7V or slightly higher car battery voltage range. Such car audio supercaps start from 60-80$ and go much higher.

    rgds, Gyula
    Thanks Gyula for the links and explanation.
    It is very interesting stuff but the supercaps are certainly over budget.
    Lots of other interesting experiments in mind for which I rather spend that kind of money.

    Comment


    • #47
      Can you move the exciter coil away .. Under the table and then try to tune it..

      Comment


      • #48
        The easiest and most practical way of testing the input draw current is to use a new battery of known value, like the 9v, small 12v ones, etz... They don't cost much and would give accurate results. I use use 4 AA, in a plastic holder, as that is about what my Exciter likes to run at without heating up.
        4 to 7 volts, or so.
        My analog meter will only read the same value as the input provides, even though I'm lighting a Neon bulb brightly off of the L3 coil.

        Nick_Z

        Comment


        • #49
          Hi Nick_Z,

          What you suggest sounds good but Jaskro's problem is that his setup is extremely sensitive and it is willing to operate in the "less than 10mA current draw" mode from the power supply only. If it is not in that mode, than it draws much higher current.
          Perhaps Jaskro has already perfected the exciter I hope he can have some time to write a few sentences.

          Gyula

          Comment


          • #50
            Hi all,

            I have done some different amp draw tests. First I tried to get circuit running with a 1 ohm resistor but the amp draw jumped up and I couldn't get it oscillating any more.
            Some time ago I've ordered an electronic amp meter on ebay which came in last week and I also picked up a kill a watt meter and I've hooked those up to see what happened.
            With some adjustments I managed to get the circuit running with the electronic amp meter in series. With confusing results I might add. Some times it shows equal values but more often the amp draw is bigger compared to the values shown on the the gauge of the power supply. Because I also have the kill a watt meter running and can I see the watts consumed by the hole system and that tells me that the new electronic amp meter seem to be more accurate. Although I still get some strange readings the 2 new meters are showing similar data most of the time.

            This leads me to believe that the actual amp draw of the circuit is probably much bigger then the power supply is telling me. Not 100% sure yet but highly probable.
            It seems that the power supply is indeed effected by HF signals of the circuit and is messing with the readings. Still confusing is that readings are always very consistent and seem to be steady and stable in relation to tuning of the circuit .

            Some strange things are happening though. 1 example. If I disconnect the D4 led that is connected across the plus and minus of the power supply the amp draw on the power supply drops significantly but on the other meter the amp remains the same or even rises a little.

            In this circuit many things will remain a mystery I guess.
            Thank you all for your support!

            Comment


            • #51
              The design of the modulated of amplified and it power of inexpensive of networks. the engines are so power controlled of the modulate. The micro system and transmission view of deviations.
              new york city accounting

              Comment


              • #52
                Hi Jaskro,

                Now that I have read your recent findings I still believe the inner circuit of the power supply becomes part of the exciter circuit. This is why I have suggested to test the exciter with a separate 3 terminal voltage regulator like LM7815 etc, these regulators include mostly the same circuits (error amplifier, pass transistor, reference voltage etc) a bench power supply include but in a much less volume (assuming here that your power supply is not a switched mode but a normal linear type). But the point is it inherently has a very low output impedance like your power supply has and this is must for any comparable results in this case.
                The fact that your inserting a 1 Ohm resistor in series with the supply wire kills the low current draw may indicate that the exciter interacts with the inner circuits of the power supply, the exciter's high frequency circulating via the power supply output influences i.e. fools the current meter sensing circuits. It is very possible that placing a some nF decoupling capacitor inside between a 'hot' point of the current sense circuit and the negative ground would also kill the low current draw. Of course I do not say you open up the power supply but your decoupling capacitor placements across for instance the power supply leads also killing the low current draw may indicate this, (by shunting the high frequency directly across the power supply terminals you reduce the amount of disturbing signals entering into the supply via its output terminals).

                I understand that by using the two new meters you tend to believe (from the measurement results) that the actual current draw is higher than the supply's current meter shows (mainly in the less than 10mA current draw cases). And I also understand that you find it confusing when you find the readings are always very consistent and seem to be steady and stable in relation to tuning of the circuit.

                A possible explanation for this is that by the tuning process you simply reproduce the condition for the low current draw to happen: you always have a high current draw (80-100mA) whenever a "condition" (in your power supply) is not yet met, such condition might be a certain amount of HF current or HF voltage to be present somewhere at a circuit point it should not be present.

                you wrote:
                If I disconnect the D4 led that is connected across the plus and minus of the power supply the amp draw on the power supply drops significantly but on the other meter the amp remains the same or even rises a little.

                While this behaviour sounds just the opposite to what you found earlier (when you had to include D4 to reduce current draw) I think this purely depends on tuning conditions and on using another current meter which earlier was not there. Just curious: have you had time to measure the self capacitance of D4 LED?

                All in all (while I still may sound as I do not believe to my own eyes ) I hope you still have the mood to continue exploring this setup, read my earlier posts that might give you some test ideas and come back time to time. A good test may be for instance to run your exciter in the low current mode for say half an hour and check the transistors temperature and then run the exciter in the 80-100mA mode by slightly detuning it but still have the more or less same LED brightnesses and also check the temperature after half an hour run.

                PS it occured to me you could use a very simple current transformer as a power supply current indicator, see this link:
                Building and calibrating a low capacitance RF current meter Any toroid you may have would do, no need for an HF type core, just wind 30-40 turns of 0.2 or 0.3mm OD enameled copper wire and build the circuit. The indicator could be a small VU meter or simply your DMM in the most sensitive DC current range. You simply thread one of the power supply wires though the toroidal core once, that single turn would induce current into the 30-40 turn output coil. With this small "gadget" you could check any current change in the supply wire when you tune to the less than 10mA operation mode from the 80-100mA draw, you should see this big change via this indicator (no need for any calibration, it serves as an indicator).

                Greetings, Gyula
                Last edited by gyula; 10-02-2012, 03:06 PM. Reason: addition

                Comment


                • #53
                  Originally posted by alanstarc View Post
                  The design of the modulated of amplified and it power of inexpensive of networks. the engines are so power controlled of the modulate. The micro system and transmission view of deviations.
                  I am afraid you entered garbage you got garbage...

                  Comment


                  • #54
                    I am very sorry to say that I will not be posting new information for a while.
                    Can't explain in detail but let me say that a tragic event took place in my personal life that needs all my attention right now.
                    I probably will be back in a few weeks and despite gyula's skeptic views I certainly will continue to work on this circuit that I believe it is still very promising. Still so much that need to be explored.

                    Thanks for understanding.
                    Hopefully we can continue with more interesting discussions later on.

                    Comment


                    • #55
                      Hi Jaskro,

                      Receive my honest condolence and may the force be with you to get over the tragic event. As I wrote, just take your time as long as needed, you can continue "tinkering" any time as it is convenient for you.

                      I may have been sounding as sceptic but be assured the pieces of advice I tried to suggest have come from experiments, learned the hard way in the past. An exciter i.e. an oscillator running at such high level is not an easy 'beast' to handle and learn all its secrets. A nice challenge for sure.

                      Greetings and good health!
                      Gyula

                      Comment


                      • #56
                        @jaskro:

                        The best to you and yours! And hoping you can return shortly.

                        truesearch

                        Comment

                        Working...
                        X