Joule Thief Kit released

Discussion in 'Marketplace' started by takao21203, Jun 3, 2014.

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  1. takao21203

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  2. #12

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  3. takao21203

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    That's not the point. Yes I know there are small USB converter PCBs, and MCP1640 chips, and stuff like that, all in the $1 range.

    The kit is meant to be for DIY and to build a real, oldfashioned joule thief.

    Actually you could 5 or even more complete circuits from the kit componenents.

    It is not effective to sell $1 articles on ebay because the initial fee and the shipping costs.
     
  4. absf

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    Dec 29, 2010
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    It should be interesting for those newbies who like to step up 1.5V to something higher to do all their wonderful experiments.:D

    Allen
     
  5. takao21203

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    I have over the years actually build quite a lot such circuits. I will show them soon on my blog.

    It is a useful circuit to know for some applications, even with all these chips available. I also use (and sell) these.
     
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  6. Wendy

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    I'll be putting something similar eventually in the Experiments volume of the book.
     
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  7. #12

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    A joule thief circuit is a wonderful thing to play with. It would make a great experiment for a lot of people.
     
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  8. djsfantasi

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    I would have liked to see some schematics included of example circuits that could be built with the kit.
     
  9. takao21203

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    Yes I also got requests from customers for schematics.

    There is a link on the item page already. I will populate the wordpress page soon with content.

    The kit is designed to build various LED torch circuits, for this reason it is including inductors, PNP and NPN transistors, and also small capacitors.

    There is a webpage already with a lot of LED torch circuits on Talking Electronics.
     
  10. Brownout

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    Jan 10, 2012
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    There's a gazzilion on the web :) BTW, is wire-wrap wire still made? I think that would be easy to work with for those who don't use a kit.
     
  11. djsfantasi

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    Of course there's a gazillion schematics available. I just thought for a "kit", the potential market would be increased if schematics specific to the supplied parts were included.

    More of a marketability comment than an availability comment.
     
  12. Brownout

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    What would really be unique would be a design guide. Since all the parameters of the cores would be know for a kit, the kit user should be able to predict how the circuit will work, frequency, output voltage, etc.

    As opposed to the ones on the web where they say "wind a few turns and try...."
     
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  13. takao21203

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    I have added parts to the kit, for instance 1 K Ohm resistors, and capacitors too.

    There is some information now on the webpage but the classic joule thief is simple, and it can be built with the kit.

    Should I really make a webpage with detailed step by step instructions?
     
    Last edited: Aug 15, 2014
  14. MikeML

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    Oct 2, 2009
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    I never have understood the fascination with getting the last 3% of the energy out of a throw-away battery...

    Hell of a lot of work just to get 3% more...
     
  15. Wendy

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    It is more than that. One AA battery, one LED that has a Vf of 3.5VDC. Without the basic circuit it would not work, but the added battery life is a bonus.
     
  16. takao21203

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    I find it fascinating to build more and more new variations of it, some surface mount, some without transformers, sometimes rewinding transformers.

    I never properly understood the formular for induction coils, tough after years playing with them, I do understand most of their parameters, and the correlations of these.

    Of course, for a kit being sold, suitable cores are required.

    As for analogue electronics, I am a learner and amateur at best (even if lets say I can think into all kinds of circuits quick).

    Got myself a component tester recently, could not imagine to do without one now.
     
  17. takao21203

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    The fascination is similar to using a web schematic for an FM transmitter, the transistors not available, so it is clear it wont work with the substitute 2n3904, but after thinking into the circuit, and making modifications, it does work.

    Including to realize it needs a feedback from the antenna- inserting a thin wire into the copper spiral (works as a small capacitor).

    Without it- totally weak and distorted signal, with it, good transmission.

    It still remains a mystery to me what it does exactly (OK I understood I had to change the Biasing because the 2n3904 is a bit on the margin at 100 MHz).

    Also just using some 8 turns TOKO inductors unknown values, for all of the coils, but got it working.

    Was a really entertaining afternoon.

    Others buy a commercial failsafe kit with a printed PCB and get the same satisfaction.

    With my JT kit you can play around and the parts were all tested so they work well for these kinds of circuits, but you arent bound to a schematic and you can build quite a few different circuits.
     
  18. Brownout

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    Making a joule thief is a "hell of a lot of work????" HA! Making simple, functional circuits is playtime. The best thing about simple circuits like this is how the demonstrate basic electronic and physical principles without the need for higher integrated components. IMO, the best way to investigate electronics are by using the most basic components available. And believe it or not, I see versions of the JT in all kinds of commercial products. The switching power module in the CCF lamp I took apart was nothing more than a high voltage version of the JT. It uses a push-pull scheme for added efficiency.
     
  19. takao21203

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    I have three component kits on offer now, the first one is selling so far, the second one sold once, the third one not at all.

    I want to release two or three more:

    -One for SMD joule thief.
    -One with increased difficulty, required to open and rewind small old potcore transformers.
    -One very basic + low price, just designed to build one or two joule thiefs with no modifications.

    As soon as the others sell a little more, I will put efforts into this.

    Joule thief technically is a blocking oscillator, I found for instance an old PDF where the circuit is explained professionally, it was used in the 1960s and 1970s, if well designed it can outperform ICs, and archieve more than 80% efficiency.

    The circuit existed before the term Joule Thief was coined.

    I can dig out the PDF + link if requested, I think there is a website with quite a few old books from Siemens scanned and published as PDFs, with permission. Not sure if it was Siemens tough, but one of these large Electronic companies. Maybe it was Valvo.
     
  20. Brownout

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    That's correct. Blocking oscillators have been around a long time, and there's nothing special about the JT. It's just an old design given a new name. Blocking oscillators have been used in circuits having nothing to do with power. Some old TV's I worked on used them for horizontal and vertical oscillators. Technically, a blocking oscillator uses core saturation to achieve sustained oscillations. I think many of the JT's posted online depends more on saturation of the transistor. To really make a blocking oscillator, you should have a core with specific saturation characteristics.
     
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