Joule Lamp

[stprue]

Just a quick question, has anybody tried this setup using a pancake style coil?

[Lynxsteam]

I have tried just about everything.  The pancake coil will give you very high voltage but when you load it, the oscillations often stop.  Doesn't mean it can't work with some more thought and effort.  I wasn't interested in lighting just one bulb so I moved on to designs that could handle larger loads. 

Imagine a machine that runs off energy stored in a flywheel.  If the flywheel is small you can only extract a little energy or it will stall.  If the flywheel is large you can pull a lot of energy out of it and it will keep turning with just short bursts of input energy. 

[JouleSeeker]

  Lynxsteam -- I really like your approach of building these super-coils (your latest design) and making them available -- selling them!  I hope they sell like hot-cakes.  I'm very glad to do testing (and see response below to your questions).

We need some way to get these inventions out the door, and you're taking a marketing approach which I hope works well, very well.  There is nothing wrong IMHO with seeking a fair return on an invention! 

I have encouraged Slider to take his small device (small, one-led and different from yours) into production mode also -- based on your bold step here.  At least I think it is bold and great!

We have on these boards discussed the dangers associated with seeking a patent; but you're not doing that.

Joule Seeker,

Can you put in simple terms what the fantastic results you are seeing means?  For instance you are seeing more lumens per watt than the bulbs are specified to put out.  And we are inputting fewer watts than the bulbs would normally require.  What should someone expect from this type of DC converter?  Dim light and super efficiency, or good light at the same power draw as House grid?
As you report higher and higher lumens per watt it sounds really good, but we need some context or perspective.
For instance 109lumens per watt sounds good, but the bulbs are running with about half the watts they require.  Does that mean we need twice as many bulbs for useful light in a house?

Good questions; I wish I knew all the answers.   Yesterday with your "cranberry" air-core design (admittedly with added ferrite rods) I got 612 Lumens with 5.6 W input (5 bulbs, running at 12.8 V) -- which I think is amazing really.  The bulbs are designed for 1.5 W (each); this is running a little below that, 1.1 W each.

A 40-watt incandescent puts out about 500 Lumens, roughly 13 Lm/W, so 109 Lm/W is much better -- and 612 Lumens is quite bright.

Yes, we seem to be above the rated Lumens per watt typical for LED bulbs.  Two caveats:
1.  this particular bulb is from China and my experience is that they aren't careful in giving accurate lumens values (I've tested a dozen or so Chinese LED bulbs in my light box)
2.  Using Lumens out to estimate POWER-out is a start, but not a compelling result yet IMO.  For instance, it may be that at higher frequency and voltage, these bulbs exceed their rated Lm/W but without any ou-behavior involved.  I suspect that is the case.
So I would like to take the "next step" and actually measure the WATTS out from this device....  I'm working on it and would appreciate any ideas.

I would like to dump the AC power-out into a resistance-load, warm water, and measure the temp-rise.  Simple calorimeter approach.  If this loading does not itself change the circuit's efficiency!

As Mags says, it may be that the LED bulb first rectifies the AC input -- this is what I found when I disassembled a CFL bulb; but I haven't disassembled an LED bulb yet.   DC out makes it easier to measure Power out (IMO) -- so this is another approach to measuring P-out.

Thoughts?

[Lynxsteam]

Just to clarify, this will be "open source" information.  I am just going to offer ready made ones in case someone doesn't have the materials or finds that quantity minimums are too much $$$.  The 11# spools of copper I buy now are about $140 each, insulated wire is $79 a spool.  There is 450 feet of wire on the new model.

To measure power output is going to be very tricky.  Output changes according to load.  If you could get a resistive load like a heating element and adjust the Ohms until you get to the same hz as you would expect with the LED bulbs it might be accurate.  This is how we measure output of alternators at different rpm.  My guess is - there is very little energy lost in the DC-AC conversion.  So if you have 5 watts in at 95% that is 4.75 watts out, divided by 95 volts = 50 ma which is about right for LEDs.  I do think the frequency is like a "virtual amperage" in that the electrons impinge on the load with much more velocity. 

Sort of the difference between firing a bullet from a rifle vs dropping a bullet on your shoe.

[e2matrix]

Nice work guys!   I've just got a little info to add as I'm not sure how you are measuring Lumens.   I spent years on a forum that is very concerned with accurate measurement of lumen output.   What is not commonly understood is that you need more than just a light meter to get accurate measurement.   The only way to get accurate measurements is with an integrating sphere where the light is inside a sphere.  Measurements done any other way can easily be off by 50% or more.  I don't want to dampen any enthusiasm.  Seeing Lynxstreams vid I was impressed with the amount of light and I'm sure you are onto something good here.   Just be aware of the Lumen measurement situation though.  Integrating sphere's are very expensive but Google search DIY integrating sphere's and you'll find some ways to make your own for reasonable if it is really important to have those Lumens exact.