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Showing content with the highest reputation since 10/18/2017 in all areas

  1. 1 point

    Solar Powered Water Pump

    I have some questions I was hoping someone would help me work through. I am building an outdoor fountain that I want powered by a solar cell. Can I run the solar cell wires directly into the BLDC motor and have it operate only when sun is shining? The brighter the sun the faster the motor turns. Or do I need more circuitry to make it work? If I do hook up a small 3.7 v 2000 mAh Li Ion battery, I need a charge controller? And what? Pump Voltage VDC - 6.0 Nominal Current Draw: 0.27 Amps Power Usage: 7.0 Watts Solar cell Output Voltage: 0.5 volts (Vmax) Output Current: 3.5 Amps (Imax) Average Power: 1.75 Watts Is there any way to turn the motor on for 1 minute every hour on the hour? Miniature controller or driver of some sort? System as compact and concealable as possible. Any help out there For this one? Oh one more thing, is there a micro charge controller out there that would protect the battery when it was full by dumping the load into some LED’s or something of that nature?
  2. 1 point

    12v lamp Dimmer lamp ideas?

    I have a 12v transformer for interior lights and a few lights for it, but want to make it a dimmer light. the working amps are 250mA. I would like to know how to wire up these three ways, so i can try each one and see if its any good and use the best.... Touch lamp. touch the metal to turn on dimmest. press again for brighter and again for brighter and again for off. Manual pot adjuster. and digital potentimeter. press up to turn up and make brighter and down for darker / off, and a reset button to turn instant off. Any help and sche... will be helpfull. Thanks in advance
  3. 1 point

    STK407-070B Datasheet

    Hi, where can I find datasheet of STK407-070B? I just want to make a home made amplifier. thanks :D
  4. 1 point

    high voltage electric arc

    i need to create voltaic sparks that jumps from one electrode to another between a medium of air. sort of like jacob's ladder. the distance of one electrode to another is about 0.5". i gather that the breakdown voltage of air for said distance is about 4kV. i'm targeting more of around 20-30kV, just to be sure. the sparks do not have to last long, just about 1 sec, max. the purpose of this simple contraption? i want to create a sustained jacob's ladder, rather than one lasting only a second (as the described contraption does). so what this contraption will do is apply the breakdown voltage, ionizing the air and then the sustained high voltage will be supplied by my DC arc welder that outputs 25V @ 50A. don't worry, i won't put the two to be electrically parallel to each other. the contraption has to be very cheap (would simply winding a step-up transformer be enough)?? i've tried different sources, the cheapest i found was simply buying a cheap stun gun (around $10-20) than can supply a few million volts -- pretty good. but the laws in canada does not allow the trade of any sort of weapon (even for self defense) whatsoever. i've tried looking at neon sign transformers but they cost at least $50.
  5. 1 point
    Kevin Weddle

    High Voltage low amperage

    Generating a very high voltage with a small battery is an interesting idea. In theory, a transformer can produce any voltage, depending on it's turn ratio. They can also be cascaded. Are there any designs that utilize cascaded transformers, and if so, why isn't one transformer used?
  6. 1 point

    negative ioniser

    Hi all, I am looking for a circuit that operates in 9-12 DC and will generate voltage in 2-3KV range with negiligible current. I came across many designs but interested if anyone knows any circuit that uses common step down transformer with primary and secondary reversed as the first step in conversion.I am planning to use Cockcroft–Walton multiplier to increase the voltage from transformer. Flyback transformers are difficult to find /not familar for me to use.But would defenitely consider if its readily available I came across this circuit and like to know if something similar can be tried with a step down transformer http://www.aaroncake.net/circuits/flampdrv.asp If anyone know any schematic with small flyback transformers I would be glad to try.I am only concerened about availability. The whole purpose is to make a negative ion generator to clean dust from my vinyls. I donot want to use the ones based on Pizo electric but somehing that will generate a massive negative ion flow that will neutralize all sticky dust on my LPs .The prime consideration is making it as small as possible.
  7. 1 point

    negative ioniser

    The same basic blocking oscillator circuit, normally used to drive a flyback transformer, can also drive a centre tapped or dual primary mains transformer. Here's an example of a capacitor charger using a mains transformer with a centre tapped primary. It should be able to drive a voltage multiplier circuit.                     C1 1 uF                   D2 1N4948   R2                 +------||------+        T1    1.2kV PRV  1K 1W                 |              |           +-----|>|-----/\/\---+------o +                 | R1 4.7K, 1W  |   red  ||( blk                 |                 +-----/\/\-----+------+ ||(                     |                 |                  yel )||(                   +_|_ C2  + o----------------------------------+ ||(                    --- 300 uF                 |                  red )||(                   - |  450 V                 |      +--------------+ ||(                     |                 |  Q1  |                ||( blk                 | 6 to 12         |    |/ C                  +--------------------+------o - VDC, 2A         +----|    2N3055    Stancor P-6134             D1 _|_   |\ E           117 V Primary (blk-blk)         1N4007 /_\     |            6.3 VCT Secondary (red-yel-red)                 |      |  - o------------+------+ http://www.repairfaq.org/sam/samschem.htm#schssi
  8. 1 point

    Electronic Gun !!!!!!!!!

  9. 1 point


    TOYOTA Car indicator flasher part number TOYOTA:81980-50030.
  10. 1 point

    Small vacuum tube Tesla coil

    nice old fashioned work is it dangerous to touch the fling electrons ????
  11. 1 point

    My ZVS Flyback Driver with pcb

    This is my ZVS Flyback driver with pcb/desinged. It is very simple. ZVS Flyback Driver ;D <Y> ./'\.
  12. 1 point
    Silent Jack

    High Voltage low amperage

    No, lead acid batteries are far too heavy. I was looking at maybe NiMH or more likely some LiPo batteries commonly used on RC cars and the like. Looking at 3-6AmpH class batteries. Might lean towards 12V, since there is so much standard stuff for that as far as wiring and other components. Safety is of course important and any good suggestions on grounding/shielding are welcome and appreciated.
  13. 1 point
    Kevin Weddle

    High Voltage low amperage

    A transformer will deliver a high enough voltage that you want. High voltage transformers are expensive, but can usually be found in electronics products no longer used, and be cascaded for high voltgage. Be aware that high voltage burns and shock can occur, and a high enough voltage can lay you in the hospital.
  14. 1 point

    High Voltage low amperage

    10,000V at 0.02A is 200W which is a lot of power for a little power supply.
  15. 1 point

    High Voltage low amperage

    Possibly a flyback converter? They can usually be output current limited by limiting the current availiable to the transformer. Do you need it to be highly efficient or are you not too fussed?
  16. 1 point
    Silent Jack

    Electronic Gun !!!!!!!!!

    [i would not encourage children to develop high tech weaponry and would firmly discourage them from using them on themselves or others.] I saw a project online once that took a page from the XREF taser shotgun rounds, concept. It used pressurized air to propel a charged disposable camera capacitor, prongs first out of a simple barrel. Interesting concept, though from what I read, the 330V would be far to little to achieve the taser effect. That and I understand a specific waveform is needed to affect strictly skeletal muscle and not cardiac muscle. Seems like a safety concern to me.
  17. 1 point

    Electronic suplus stores

    Hello RFamateur and welcome to the form. Here are a few. These have stuff some good lot outdated. http://www.goldmine-elec.com/default.htm http://unicornelectronics.com/prod.htm http://www.mpja.com/category/LEDs/LEDs.asp http://www.futurlec.com/index.shtml http://www.allelectronics.com/ http://www.danssmallpartsandkits.net/ http://www.alltronics.com/assortments.htm These are good suppliers http://www.mouser.com/index.cfm?handler=home http://www.futureelectronics.com/en/Pages/index.aspx http://www.web-tronics.com/ http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDisplay?storeId=10001&catalogId=10001&langId=-1 That should get you going. gogo
  18. 1 point

    Electronic Gun !!!!!!!!!

    Hi Shantanu, Electrolytic capacitors have a vent on top to slowly release gasses that build up when the capacitor is connected with backwards polarity then has a high current. With a very high current, the vent cannot release the gasses slowly so the capacitor explodes. A 9V battery cannot provide a very high current. Maybe a battery made with series-connected AA Ni-Cad or Ni-MH cells would provide enough current for a backwards electrolytic capacitor to explode. Bad-smelling "fluff" comes out.
  19. 1 point
    Here is the book in pdf for you all. You can press the free button and you have to wait about a minute then it gives you the links. Just pick one. http://rapidshare.com/files/3372603/Practical_Electronics_for_Inventors.pdf
  20. 1 point
    Calm down people. It is not Mixos's fault, if it is against the law he has to remove the content. This site is very good for asking electronic related questions, I have yet to find a better one.
  21. 1 point
    I am very sad too :-[ [move] :'( :-[ :-\ :'( :-[[/move] No doubt, ER has been the one of most attractive features of the site. All the thanks and respect goes to Mr. Ante for such a good contribution to this part of site. I now request MIXOS to leave the contents as it is not reasonable to throw away ones friends(books).
  22. 1 point
    Here is all I have Playstation2_Repairguide.pdf
  23. 1 point

    Electronics Goldmine!!

    MP, Just click on
  24. 1 point

    0-30 Vdc Stabilized Power Supply

    R16 is 1K and is OK ???
  25. 1 point

    0-30 Vdc Stabilized Power Supply

    Think of the commas as periods or the periods as commas. These are used differently in different continents. It means the same. MP